LTE/SAE System Overview: Student Book LZT1238828 R15A
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LTE/SAE System Overview
STUDENT BOOK LZT1238828 R15A
LZT1238828 R15A
LTE/SAE System Overview
DISCLAIMER This book is a training document and contains simplifications. Therefore, it must not be considered as a specification of the system. The contents of this document are subject to revision without notice due to ongoing progress in methodology, design and manufacturing. Ericsson shall have no liability for any error or damage of any kind resulting from the use of this document. This document is not intended to replace the technical documentation that was shipped with your system. Always refer to that technical documentation during operation and maintenance.
© Ericsson AB 2017
This document was produced by Ericsson. •
The book is to be used for training purposes only and it is strictly prohibited to copy, reproduce, disclose or distribute it in any manner without the express written consent from Ericsson.
This Student Book, LZT1238828, R15A supports course number LZU1087020.
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Table of Contents
Table of Contents 1 LTE/SAE INTRODUCTION .............................................................. 11 1 INTRODUCTION ............................................................................12 1.1 LTE BASIC REQUIREMENTS (REL 8) ........................................ 16 1.1.1 TARGET RATES FOR USER THROUGHPUT.......................... 17 1.1.2 TARGETS FOR SPECTRUM EFFICIENCY .............................. 18 1.2 OVERALL EVOLVED PACKET SYSTEM (EPS) ARCHITECTURE .................................................................................19 2 LTE RADIO INTERFACE ................................................................22 3 PROTOCOL STATES AND MOBILITY ........................................... 24 4 QOS HANDLING ............................................................................25 5 SUMMARY .....................................................................................28
2 EPC ARCHITECTURE ..................................................................... 29 1 EPC ARCHITECTURE....................................................................30 1.1 ERICSSON VOLTE ARCHITECTURE ......................................... 31 1.2 MOBILITY MANAGEMENT ENTITY (MME) ................................. 31 1.2.1 MKVIII .......................................................................................32 1.2.2 MKX ..........................................................................................34 1.2.3 VIRTUAL SGSN-MME ..............................................................36 1.3 VSGSN-MME ARCHITECTURE ..................................................36 1.4 POLICY AND CHARGING RULES FUNCTION (PCRF) .............. 38 1.5 HOME SUBSCRIBER SERVER (HSS) ........................................ 39 1.6 SERVING GATEWAY (SGW) ......................................................39 1.7 PACKET DATA NETWORK GATEWAY (PGW) ........................... 40 2 MME AND S-GW POOLING ...........................................................43 3 OVERVIEW SAE/LTE INTERFACES .............................................. 45
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3.1 UU INTERFACE...........................................................................47 3.2 S1 INTERFACE ...........................................................................47 3.3 X2 INTERFACE ...........................................................................49 3.4 OTHER EPS INTERFACES .........................................................49 4 EVOLVED IP NETWORK SOLUTION............................................. 52 5 SUMMARY .....................................................................................54
3 E-UTRAN ARCHITECTURE ............................................................ 57 1 INTRODUCTION ............................................................................58 1.1 ENB FUNCTIONALITY ................................................................58 2 LTE AIR INTERFACE .....................................................................61 2.1 OFDMA/SC-FDMA FREQUENCY DOMAIN................................. 61 2.2 OFDMA/SC-FDMA TIME DOMAIN .............................................. 63 2.3 ADAPTIVE MODULATION...........................................................65 2.4 ADAPTIVE CODING ....................................................................66 2.5 MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) ......................... 67 2.6 LTE SCHEDULING ......................................................................68 2.7 DOWNLINK PHYSICAL BIT RATES ............................................ 68 2.8 CARRIER AGGREGATION .........................................................70 2.9 UPLINK PHYSICAL BIT RATES ..................................................74 2.10 CARRIER AGGREGATION IN UPLINK ..................................... 74 2.11 REFERENCE SIGNALS.............................................................74 2.12 LEAN CARRIER.........................................................................76 2.13 UE CATEGORIES......................................................................76 2.14 LTE FREQUENCY BANDS ........................................................79 2.15 TDD OPERATION......................................................................81 3 LTE-ADVANCED ............................................................................82 4 ERICSSON RADIO SYSTEM .........................................................89
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Table of Contents 4.1 SITE TYPES ................................................................................92 4.1.1 SERIES .....................................................................................93 4.2 RADIO NODES .......................................................................... 100 4.2.1 RADIO MODULES .................................................................. 101 4.2.2 SMAL CELLS .......................................................................... 104 4.2.3 BASEBAND MODULES .......................................................... 109 4.3 TRANSPORT ............................................................................. 114 4.3.1 ERICSSON BACKHAUL ......................................................... 115 4.3.2 ERICSSON FRONTHAUL ....................................................... 116 4.4 ENCLOSURE ............................................................................. 117 4.4.1 ENCLOSURE NEW FAMILY ................................................... 119 4.4.2 POWER PRODUCTS.............................................................. 120 5 SYNCHRONIZATION IN LTE ....................................................... 121 5.1 WHY AND WHEN SYNCHRONIZATION IS NEEDED ............... 121 5.2 WHAT ARE THE DIFFERENT TYPES OF SYNCHRONIZATION ......................................................................... 123 5.3 WHAT ARE THE SOLUTIONS FOR SYNCHRONIZATION? ..... 123 5.4 ERICSSONS SYNCHRONIZATION ALTERNATIVES ............... 124 6 SECURITY IN LTE ........................................................................ 126 6.1 INTEGRATED SECURITY CONTROL ....................................... 127 6.2 AIR INTERFACE SECURITY ..................................................... 128 6.3
TRANSPORT NETWORK SECURITY ....................................... 128
6.4 TRANSPORT AND AIR INTERFACE SECURITY ...................... 129 6.5 SMALL CELL AUTO INTEGRATION ON UNTRUSTED BACKHAUL ........................................................................................130 6.6 DIGITAL CERTIFICATE AND PKI INFRASTRUCTURE ............ 132 6.7 REAL TIME SECURITY EVENT LOGGING ............................... 133 6.8 NODE HARDENING .................................................................. 134
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6.9 SECURE EXECUTION ENVIRONMENT ................................... 134 7 SUMMARY ...................................................................................136
4 KEY LTE SOLUTIONS .................................................................. 137 1 VOICE AND LTE........................................................................... 138 1.1 CS FALLBACK ........................................................................... 139 1.1.1 EMERGENCY CALL HANDLING ............................................ 140 1.2 VOLTE (IMS BASED MMTEL) ................................................... 141 1.2.1 IMS AND STANDARDIZATION ............................................... 141 1.2.2 MMTEL BASIC SERVICE ....................................................... 143 1.2.3 THE MMTEL SERVICE PLATFORM....................................... 144 1.2.4 ERICSSON IMS PORTFOLIO OVERVIEW ............................. 145 1.2.5 ERICSSON IMS NODES ........................................................ 146 1.3 PORTFOLIO RELATED TO IMS ................................................ 150 1.3.1 INTERWORKING .................................................................... 150 1.3.2 SUPPORT SYSTEMS ............................................................. 151 1.3.3 ERICSSON ENRICHED COMMUNICATION SERVICES........ 155 1.3.4 VOLTE ARCHITECTURE........................................................ 156 1.3.5 IMS ARCHITECTURE ............................................................. 157 1.3.6 MOBILITY - SINGLE RADIO VOICE CALL CONTINUITY (SRVCC) ............................................................................................161 1.4 WI-FI CALLING .......................................................................... 163 2
LTE BROADCAST ........................................................................ 166
2.1 LTE BROADCAST NETWORK ARCHITECTURE...................... 167 2.2 SERVICES AND MBSFN PRINCIPLE ....................................... 168 3 LOCATION SERVICES ................................................................. 170 3.1 GATEWAY MOBILE POSITIONING CENTER (GMPC) FUNCTIONAL OVERVIEW ................................................................ 171
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Table of Contents 3.2 SERVING MOBILE POSITIONING CENTER (SMPC) FUNCTIONAL OVERVIEW ................................................................ 172 4 SUMMARY ...................................................................................173
5 LTE MOBILITY............................................................................... 175 1 INTRODUCTION .......................................................................... 176 2 IDLE MODE MOBILITY................................................................. 177 2.1 PERIODIC TAU.......................................................................... 177 3 CONNECTED MODE MOBILITY .................................................. 179 3.1 INTRA LTE INTRA FREQUENCY HANDOVER ......................... 181 3.1.1 INTRA-LTE HANDOVER TYPES ............................................ 182 3.2 POOR COVERAGE HANDLING ................................................ 183 3.2.1 SESSION CONTINUITY, INTER-FREQUENCY AND IRAT HANDOVER .......................................................................................184 3.2.2 LTE AND WI-FI MOBILITY ...................................................... 185 4 SUMMARY ...................................................................................186
6 OPERATION AND MAINTENANCE IN LTE RAN ......................... 187 1 OVERVIEW...................................................................................188 2 O&M ARCHITECTURE IN LTE RAN............................................. 194 2.1 OSS-RC AND ENM.................................................................... 194 2.2 G1 RBS (MACRO, MICRO) O&M ARCHITECTURE .................. 196 2.3 PICO RBS (RBS 6402) O&M ARCHITECTURE ......................... 197 2.4 G2 RBS (BASEBAND 52XX) O&M ARCHITECTURE ................ 197 3 OPERATION AND MAINTENANCE (O&M) AREAS ..................... 198 3.1 CONFIGURATION MANAGEMENT ........................................... 198 3.2 FAULT MANAGEMENT ............................................................. 200 3.3 SECURITY MANAGEMENT....................................................... 203 3.4 SOFTWARE MANAGEMENT .................................................... 203 3.5 PERFORMANCE MANAGEMENT ............................................. 205
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4 SON CONCEPTS ......................................................................... 208 4.1 INTRODUCTION:....................................................................... 208 4.2 SON RELATED FEATURES ...................................................... 210 4.2.1 AUTOMATED NEIGHBOR RELATIONS (ANR) ...................... 210 4.2.2 AUTOMATED MOBILITY OPTIMIZATION .............................. 215 4.2.3 AUTOINTEGRATION OF RBS (AUTO PROVISIONING) ........ 216 4.2.4 AUTOMATIC PCI ASSIGNMENT ............................................ 218 4.2.5 ADVANCED CELL SUPERVISION ......................................... 220 4.2.6 INTER-CELL INTERFACE COORDINATION .......................... 221 4.2.7 SON OPTIMIZATION MANAGER ........................................... 222 5 HARDWARE MANAGEMENT FEATURES ................................... 225 5.1 MULTI-CABINET CONTROL ..................................................... 225 5.2 ANTENNA SYSTEM MONITORING .......................................... 225 6 OTHER LTE RBS KEY O&M FEATURES ..................................... 228 6.1 FAULT CORRELATION RULE ENGINE .................................... 228 6.2 PLUG AND PLAY OF HARDWARE ........................................... 229 6.3 CO-SITING AND MIXED MODE SUPPORT .............................. 229 6.4 DIRECT READING OF KPIS...................................................... 229 6.5 SHARED NETWORK SUPPORT ............................................... 230 6.6 MINIMIZATION OF DRIVE TESTS ............................................ 230 7 SERVICES ....................................................................................232 7.1 PROACTIVE SUPPORT SERVICES ......................................... 232 8 SUMMARY ...................................................................................233
7 THE ROAD TO 5G ......................................................................... 235 1 5G BACKGROUND AND CONCEPTS.......................................... 236 1.1 MOBILE SUBSCRIPTIONS GROWTH ...................................... 236 1.2 5G IMPACT ON NETWORK SOCIETY ...................................... 238
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Table of Contents 1.3 5G IMPACT ON ICT – INFORMATION AND COMMUNICATIONS TECHNOLOGY ................................................ 239 1.3.1 NEW PRACTICES NEEDED ................................................... 239 2 THE STANDARDIZATION ............................................................ 241 2.1 3GPP .........................................................................................242 2.2 METIS ........................................................................................243 3 EVOLUTION OF MOBILE BROADBAND ...................................... 246 3.1 5G USES CASES ...................................................................... 247 3.1.1 SMART GRID.......................................................................... 248 3.2 VIRTUALIZATION ...................................................................... 249 3.2.1 NFV AND SDN ........................................................................ 250 3.2.2 ERICSSON HDS ..................................................................... 252 4 NETWORK ARCHITECTURE ....................................................... 254 4.1 LTE REFERENCE ARCHITECTURE ......................................... 254 4.1.1 INTERFACES ......................................................................... 254 4.2 SIMILAR LOGICAL NETWORK ................................................. 255 4.3 COMMON NETWORK ARCHITECTURE................................... 255 4.4 RADIO ACCESS ........................................................................ 257 4.4.1 MASSIVE MIMO ..................................................................... 260 4.4.2 ERICSSON RADIO SYSTEM.................................................. 261 5 SUMMARY ...................................................................................262
8 INDEX ............................................................................................ 263 9 TABLE OF FIGURES ..................................................................... 269 10 ABBREVIATIONS AND ACRONYMS ......................................... 273
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LTE/SAE Introduction
1 LTE/SAE Introduction
Objectives On completion of this chapter the students will be able to: 1 Explain the background and architecture of E-UTRAN and EPC 1.1 Describe the evolution of cellular networks 1.2 Summarize the evolution of 3GPP releases, from release 99 to release 14 1.3 Explain the logical architecture of EPS and the interworking with other technologies 1.4 Explain the EPS bearer concept and give an overview of the LTE QoS framework
Figure 1-1: Objectives of Chapter 1
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LTE/SAE System Overview
1
INTRODUCTION This course describes the Long Term Evolution (LTE) and System Architecture Evolution (SAE) for third generation cellular networks as in Release 8 of 3GPP (Third Generation Partnership Project). The focus is on the system from a Mobile Broadband (MBB) service point of view. Voice service is briefly discussed in the IMS chapter. The term “generation” regarding cellular network evolution is sometimes misleading and not always accurate. However, many people often refer to “2G”, “3G” or even “4G” when it comes to the different generations of the mobile telecommunications systems. The following historical overview is based on conventional and informal terms in the mobile industry, media and press. First generation (1G) of modern cellular networks includes e.g. NMT (Nordic Mobile Telephony), AMPS (Advanced Mobile Phone Service) and TACS (Total Access Communication System). These systems all have in common that the user traffic, which is voice, is transmitted with analogue FDMA (Frequency Division Multiple Access) radio techniques. NMT was developed during the seventies and launched 1981. Second generation (2G) includes systems like GSM (Global System for Mobile communications), D-AMPS (Dual-mode AMPS), PDC (Personal Digital Communications) and IS-95. The new thing with these systems was that they supported both voice and data traffic with digital TDMA (Time Division Multiple Access) or CDMA (Code Division Multiple Access) circuit switched radio techniques. GSM standardization started in 1982 and it was launched 1991. Enhancements of 2G, like the introduction of packet data GPRS (General Packet Radio Service), is often referred to as 2.5G. Further enhancements, like EDGE (Enhanced Data rates for GSM and TDMA Evolution), is referred to as 2.75G. In 1986, the ITU (International Telecommunication Union) started to work on the IMT-2000 standard, which is a guideline for every Third generation (3G) standard. In 1992, the World Administrative Radio Conference (WARC) identified the radio frequency bands 1885-2025 and 2110-2200 MHz as the common worldwide spectrum for 3G systems. In January 1998, European Telecommunications Standards Institute (ETSI) reached a consensus where WCDMA (Wideband Code Division Multiple Access) and TD-CDMA (Time Division- Code Division Multiple Access) were chosen as multiple access methods for the FDD (Frequency Division Duplex) and TDD (Time Division Duplex) mode of UMTS (Universal Mobile Telecommunication System), respectively. UMTS is the term used in Europe for 3G systems. 3G was commercially launched 2001 in Japan and 2003 in Europe.
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LTE/SAE Introduction
Figure 1-2: History briefly summarizes the history of cellular technologies. › 1G FDMA (NMT, AMPS, TACS)
80’s
- Voice (analog traffic, digital signaling)
› 2G TDMA (GSM, D-AMPS, PDC) and CDMA (IS-95) - Voice, SMS, CS data transfer ~ 9.6 kbit/s (50 kbit/s HSCSD)
90’s
› 2.5G TDMA (GPRS)
00’s
- PS data transfer ~ 50 kbit/s
› 2.75G TDMA (GPRS+EDGE)
00’s
- PS data ~ 500kbit/s
› 3-3.5G WCDMA (UMTS) and CDMA 2000
00’s
- PS & CS data transfer ~ 14-84 Mbit/s (HSPA/HSPA+), Voice, SMS
› 3.9G OFDMA (LTE/SAE) - PS Data and
2010
Voice (VoIP) for LTE ~ 300 Mbit/s
› 4G OFDMA (LTE Advanced/Pro)
2015
– IMT Advanced (3GPP Rel 10-13) – Higher spectrum efficiency, ~ 1 Gbit/s
› 5G OFDMA (5G, 5E, 5X…)
2020
– IMT 2020 (3GPP Rel 14- ) – Lower latency, flexibility, energy efficiency,… ~10 Gbit/s
Figure 1-2: History
The 3rd Generation Partnership Project (3GPP) is a collaboration agreement that was established in December 1998. The collaboration agreement brings together a number of telecommunications standards bodies, e.g. ARIB, CCSA, ETSI, TTA and TTC. The original scope of 3GPP was to produce globally applicable Technical Specifications and Technical Reports for a 3rd Generation Mobile System based on evolved GSM core networks and the radio access technologies that they support (i.e., Universal Terrestrial Radio Access (UTRA) both Frequency Division Duplex (FDD) and Time Division Duplex (TDD) modes). The scope was subsequently amended to include the maintenance and development of the Global System for Mobile communication (GSM) Technical Specifications and Technical Reports including evolved radio access technologies (e.g. General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE)). See www.3gpp.org for further information. The first practically implemented 3GPP specification for WCDMA was released and frozen 1999 and is called Release 99. WCDMA Release 99 supports both circuit switched (CS) and packet switched (PS) traffic up to a theoretical rate 2 Mbps. The evolution of 3G called HSDPA (High Speed Downlink Packet Access, specified in Release 5 - 2002) and HSUPA (High Speed Uplink Packet Access, specified in Release 6 – 2004) increase the maximum downlink (DL) bit rate to 14 Mbps and the uplink (UL) rate to maximum 5.76 Mbps. HSDPA and HSUPA is referred to as HSPA (High Speed Packet Access). HSUPA is also called EUL (Enhanced Uplink).
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LTE/SAE System Overview
The next step for WCDMA, called HSPA evolution or HSPA+, is currently ongoing (specified in Release 7 and 8) and aims to increase the maximum bit rates even further (up to 42 Mbps in DL). This is accomplished using e.g. MIMO (Multiple Input Multiple Output) antenna solutions and Higher Order Modulation (HOM). In September 2007 the 3GPP family was extended with yet another member, the Evolved UTRAN (E-UTRAN). The work with creating the concept was officially started in the summer of 2006 when the study phase was successfully completed and the 3GPP work item “3G Long Term Evolution – Evolved Packet System RAN” (LTE) commenced. More than 50 companies and research institutes are participating in the largest joint standardization effort ever to specify the new world wide radio access and the evolved core network technology. Ericsson is playing a key role as an important and visual driver in this process. R99 3G Rel 4
WCDMA
Rel 5
Rel 6
WCDMA/HSPA HSDPA
HSUPA MBMS
Rel 7
Rel 8
HSPA Evolution MIMO HOM CPC
Further enhancements
5G
4G Rel 9
Rel 10-13
Rel 14-
LTE Dual Band support IRAT Enhancements
LTE Advanced Pro
LTE Evolution & NR
MIMO, MTC, LAA and D2D enhancements
› HSPA / HSPA + – gradually improved performance at a low additional cost.
› LTE – improved performance in a wide range of spectrum allocations with increased simplicity and reduced cost.
Figure 1-3: 3G Evolution
The standard development in 3GPP is grouped into two work items, where Long Term Evolution (LTE) targets the radio network evolution and System Architecture Evolution (SAE) targets the evolution of the packet core network. Common to both LTE and SAE is that only a Packet Switched (PS) domain will be specified. The result of these work items are the Evolved UTRAN (EUTRAN) and the Evolved Packet Core (EPC). These together (E-UTRAN+EPC) builds the Evolved Packet System (EPS). LTE/SAE is specified from Release 8. Note that LTE and SAE refer to the work items in 3GPP. The name of the actual Radio Access Network (RAN) is E-UTRAN and the name of the Core Network (CN) is EPC.
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LTE/SAE Introduction
A parallel Partnership Project was also established - "3GPP2," which, quite similar to its sister project 3GPP, also standardizes International Telecommunication Union's (ITU) International Mobile Telecommunications "IMT-2000" based networks. 3GPP2 focuses on the evolution of cdmaOne with cdma2000 and EV-DO (HRPD) while 3GPP focuses on the evolution of GSM, WCDMA, HSPA and LTE. 3GPP2 is divided into four Technical specification groups comprised of representatives from the Project's Individual Member companies. The TSGs are: -
TSG-A for Access Network Interfaces - TSG-C for cdma2000 - TSG-S Services and Systems Aspects - TSG-X Core Networks GSM Track (3GPP)
GSM
WCDMA
HSPA/HSPA+
LTE LTE FDD FDD-and TDD - TDD
TD-SCDMA CDMA Track (3GPP2)
CDMA One
EVDO Rev A 2001
2005
2008
2010
LTE is the Global standard for Mobile Broadband in high speed - FDD and TDD Figure 1-4: Mobile System Evolution
The E-UTRAN standard is based on Orthogonal Frequency Division Multiplexing (OFDM) and OFDMA (Orthogonal Frequency Division Multiple Access) downlink operation and Single Carrier Frequency Domain Multiple Access (SC-FDMA) uplink operation. These choices support great spectrum flexibility with a number of possible deployments from 1.4 MHz up to 20 MHz spectrum allocations. It will support both FDD and TDD mode of operation and targets both a paired spectrum allocation with uplink and downlink separated in frequency, and unpaired spectrum with uplink and downlink operating on the same frequency. Furthermore, E-UTRAN supports use of different MIMO (Multiple Input Multiple Output) multiple antenna configurations. This increases the data rates and spectrum efficiency. LTE is sometimes referred to as 3.9G. Why not 4G? Well, ITU has defined IMT Advanced, which is the follower to IMT2000. IMT Advanced is regarded as 4G and is meant to support theoretical bitrates up to approximately 1Gbit/s and may be deployed with LTE Advanced as a foundation.
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LTE/SAE System Overview
The first commercial LTE networks based on Release 8 was implemented in 2009. EPS in Release 8 is based on a simplified network architecture compared to Release 6. The number of user-plane nodes is reduced from four in Release 6 (NodeB, RNC, SGSN and GGSN) to only two (e-NodeB and SAE-GW) in EPS. The SAE-GW can be divided into a Serving GW (S-GW) and a Packet Data GW (P-GW), but often resides in the same physical node, referred to as SAE-GW or P/S-GW. A control plane node called MME (Mobility Management Entity) is also part of EPC.
1.1
LTE Basic Requirements (Rel 8) The performance of LTE as specified in Release 8 shall fulfill a number of requirements regarding throughput and latency listed below. This seems to be quite easily achieved, thanks to, among other improvements, the simplified network architecture. Data rates of more than 300 Mbps in DL seems to be possible to reach. Also, it is a requirement that E-UTRAN architecture should reduce the cost of future network deployment whilst enabling the usage of existing site locations. It is expected that the reduction of the number of nodes and interfaces contributes to this overall goal. Furthermore, should all specified interfaces be open for multi-vendor equipment interoperability. There are two identified interfaces that will be standardized, S1 and X2. For them no major problems regarding multi-vendor interoperability have been identified during the study item phase. E-UTRA should support significantly increased instantaneous peak data rates. The supported peak data rate should scale according to size of the spectrum allocation. Note that the peak data rates may depend on the numbers of transmit and receive antennas (MIMO configuration) at the UE (User Equipment). The targets for DL and UL peak data rates are specified in terms of a reference UE configuration comprising: a) Downlink capability: 2 receive antennas at UE b) Uplink capability: 1 transmit antenna at UE For this baseline configuration, the system should support an instantaneous downlink peak data rate of 100Mbps within a 20 MHz downlink spectrum allocation (5 bps/Hz) and an instantaneous uplink peak data rate of 50Mbps (2.5 bps/Hz) within a 20MHz uplink spectrum allocation. The peak data rates should then scale linearly with the size of the spectrum allocation. In case of spectrum shared between downlink and uplink transmission, E-UTRA does not need to support the above instantaneous peak data rates simultaneously.
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LTE/SAE Introduction
The control plane latency should be lower than 100ms. The control plane latency is here defined as the transition time from ECM-IDLE to ECM-CONNECTED state (see later in this chapter for definition of these states). Also, the one-way user plane latency shall not exceed 5 ms in an unloaded situation for small IP-packets. › High data rates – – –
Downlink: >100 Mbps Uplink: >50 Mbps Cell-edge data rates 2-3 x HSPA Rel. 6 (@ 2006)
› State-of-the-art towards 4G
› Low delay/latency – –
› Cost-effective migration from current/future 3G systems
User plane RTT: < 10 ms RAN RTT Channel set-up: < 100 ms idle-to-active
› Focus on services from the packet-switched domain
› High spectral efficiency –
Targeting 3 X HSPA Rel. 6 (@ 2006 )
› Spectrum flexibility – –
Operation in a wide-range of spectrum allocations, new and existing Wide range of Bandwidth: 1.4, 3, 5, 10, 15 and 20 MHz, FDD and TDD
› Simplicity – Less signaling, Auto Configuration e-NodeB – ”PnP”, ”Simple as an Apple”
Figure 1-5: LTE 3GPP Rel 8 Targets
1.1.1
Target rates for user throughput Downlink - Target for user throughput per MHz at the 5 % point of the C.D.F., 2 to 3 times Release 6 HSDPA. - Target for averaged user throughput per MHz, 3 to 4 times Release 6 HSDPA Both targets should be achieved assuming Release 6 reference performance is based on a single Tx antenna at the Node B with enhanced performance type 1 receiver in UE whilst the E-UTRA may use a maximum of 2 Tx antennas at the Node B and 2 Rx antennas at the UE. - The supported user throughput should scale with the spectrum bandwidth. Uplink - Target for user throughput per MHz at the 5 % point of the C.D.F., 2 to 3 times Release 6 Enhanced Uplink (deployed with a single Tx antenna at the UE and 2 Rx antennas at the Node B).
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LTE/SAE System Overview
- Target for averaged user throughput per MHz, 2 to 3 times Release 6 Enhanced Uplink (deployed with a single Tx antenna at the UE and 2 Rx antennas at the Node B). - Both should be achievable by the E-UTRA using a maximum of a single Tx antenna at the UE and 2 Rx antennas at the Node B. Greater user throughput should be achievable using multiple Tx antennas at the UE. - The user throughput should scale with the spectrum bandwidth provided that the maximum transmit power is also scaled.
1.1.2
Targets for spectrum efficiency E-UTRA should deliver significantly improved spectrum efficiency and increased cell edge bit rate whilst maintaining the same site locations as deployed today. Spectrum efficiency needs to be significantly increased as following: Downlink In a loaded network, target for spectrum efficiency (bits/sec/Hz/site), 3 to 4 times Release 6 HSDPA This should be achieved assuming Release 6 reference performance is based on a single Tx antenna at the Node B with enhanced performance type 1 receiver in UE whilst the E-UTRA may use a maximum of 2 Tx antennas at the Node B and 2 Rx antennas at the UE. Uplink In a loaded network, target for spectrum efficiency (bits/sec/Hz/site), 2 to 3 times Release 6 Enhanced Uplink (deployed with a single Tx antenna at the UE and 2 Rx antennas at the Node B). This should be achievable by the E-UTRA using a maximum of a single Tx antenna at the UE and 2Rx antennas at the Node B. The 3GPP releases 9-12 will be highlighted in chapter 3, E-UTRAN Architecture.
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LTE/SAE Introduction
1.2
Overall Evolved Packet System (EPS) Architecture This part contains a description of the overall Evolved Packet Core (EPC) and EUTRAN architecture, and how other 3GPP systems are integrated into this architecture. We further provide a description of the main functions provided by the different interfaces and nodes. Overview EPS Architecture Figure 1-6: EPS Architecture shows a simplified picture of the EPS architecture. The EPS system is made up of the Evolved Packet Core (EPC) and the EUTRAN. The EPC provides access to external data networks (e.g., Internet, Corporate Networks) and operator services (e.g., MMS, MBMS). It also performs functions related to security (authentication, key agreement), subscriber information, charging and inter-access mobility (GERAN/UTRAN/E-UTRAN/IWLAN/CDMA2000 etc.). The CN also tracks the mobility of inactive terminals (i.e., terminals in power saving state). E-UTRAN performs all radio related functions for active terminals (i.e. terminals sending data). Between the EPC and E-UTRAN there is an interface called S1 and between the eNBs there is an interface called X2. Packet Switched Networks SGi
EPS (Evolved Packet System) EPC (Evolved Packet Core)
Gx
2G/3G Core Network HSS
SGs
MME
S10
S6a
MSC-S
PCRF
PGW
S5/S8 S11
S3
MME
S4
WCDMA/GSM RAN
SGW
S1-C
SGSN
E-UTRAN (Evolved UMTS Terrestrial Radio Access Network )
SAE (System Architecture Evolution)
S1-U X2
eNodeB
eNodeB
X2
eNodeB
X2
LTE (Long Term Evolution)
Figure 1-6: EPS Architecture
An E-UTRA capable terminal is connected directly to E-UTRAN. However some parts of the terminal control-plane protocol stack is also terminated in the EPC.
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Similar to UMTS, EPS supports a bearer concept for supporting end-user data services. The EPS Bearer (similar to a PDP context of previous 3GPP releases) is defined between the User Equipment (UE) and the P-GW node in the EPC (which provide the end users IP point of presence towards external networks). The EPS bearer is further sub-divided into an E-UTRAN Radio Access Bearer (E-RAB) over the radio interface and S1 between the UE and S-GW, and an S5/S8 bearer between S-GW and P-GW (S8 when S-GW and P-GW belong to different operators). End-to-end services (e.g. IP services) are multiplexed on different EPS Bearers. There is a many-to-one relation between End-to-end services and EPS Bearers.
Figure 1-7: EPS Bearer Concept
An UL TFT (Traffic Flow Template) in the UE binds an SDF (Service Data Flow) to an EPS bearer in the uplink direction. Multiple SDFs can be multiplexed onto the same EPS bearer by including multiple uplink packet filters in the UL TFT. A DL TFT in the PDN GW binds an SDF to an EPS bearer in the downlink direction. Multiple SDFs can be multiplexed onto the same EPS bearer by including multiple downlink packet filters in the DL TFT. An E-RAB transports the packets of an EPS bearer between the UE and the EPC. When an E-RAB exists there is a one-to-one mapping between this E-RAB and an EPS bearer. A data radio bearer transports the packets of an EPS bearer between a UE and an eNB. When a data radio bearer exists there is a one-to-one mapping between this data radio bearer and the EPS bearer/E-RAB.
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An S1 bearer transports the packets of an E-RAB between an eNodeB and a Serving GW. An S5/S8 bearer transports the packets of an EPS bearer between a Serving GW and a PDN GW. A UE stores a mapping between an uplink packet filter and a data radio bearer to create the binding between an SDF , Service Data Flow, and a data radio bearer in the uplink. A PDN GW stores a mapping between a downlink packet filter and an S5/S8a bearer to create the binding between an SDF and an S5/S8a bearer in the downlink. An eNB stores a one-to-one mapping between a data radio bearer and an S1 bearer to create the binding between a data radio bearer and an S1 bearer in both the uplink and downlink. A Serving GW stores a one-to-one mapping between an S1 bearer and an S5/S8a bearer to create the binding between an S1 bearer and an S5/S8a bearer in both the uplink and downlink.
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LTE/SAE System Overview
2
LTE RADIO INTERFACE The LTE radio interface is based on OFDM (Orthogonal Frequency Division Multiplex) in DL and SC-FDMA (Single Carrier Frequency Division Multiple Access) in UL. These techniques are well suited for flexible bandwidth operation. This enables operators to deploy LTE in different regions with different frequency bands and bandwidths available. OFDM also shows very good performance in highly time dispersive radio environments (i.e. many delayed and strong multipath reflexes). That is because the data stream is distributed over many subcarriers. Each subcarrier will thus have a slow symbol rate and correspondingly, a long symbol time. This means that the Inter Symbol Interference (ISI) is reduced. The uplink transmission technique, SC-FDMA, is realized in a similar manner as for the downlink (OFDM) and is also called DFTS-OFDM (Discrete Fourier Transform Spread – OFDM). The time domain structure is also similar in uplink and downlink. SC-FDMA has much lower PAPR (Peak to Average Power Ratio) than OFDM. This is one of the reasons for the choice of SC-FDMA for the uplink since the power amplifier in the UE can be manufactured at a lower cost then. In addition to that, both FDD (Frequency Division Duplex) and TDD (Time Division Duplex) is supported, which opens up for deployment in both the paired and unpaired spectrum. In FDD different frequency bands are used for UL and DL. In TDD the UL and DL transmissions are separated in time. There are pros and cons with both methods. TDD has some more overhead and latency due to the frequent switching in time. On the other hand, the TDD mode enables radio channel reciprocity, which means that UL measurements can be used for DL transmissions and vice versa. The TTD mode is also simpler to deploy in areas with limited available spectrum since it can utilize unpaired frequency bands. A half-duplex FDD mode (HD-FDD) is also defined, where the UE does not have to transmit at the same time as it receives. Therefore, more cost effective UEs can be manufactured since a duplex filter is not needed. The radio resources are defined in the time- and frequency domains and divided into so called resource blocks. Dynamic channel dependent scheduling allocates a number of these time- and frequency resources to different users at different times. Link adaptation adapts the modulation scheme and coding rate to the varying radio channel condition. HARQ (Hybrid Automatic Repeat and Request) caters for very quick layer 2 retransmission functionality. In addition, ordinary ARQ is implemented in the RLC layer. The LTE radio transmissions are based on a very short TTI (Transmission Time Interval) of 1ms, which speeds up the operation of all of the above functions. The short TTI also reduces the radio interface latency, which is one of the main concerns in LTE development.
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The figure below summarizes the main goals of the first LTE release (Rel 8): User #1 scheduled
User #2 scheduled
Δf=15k Hz
› Downlink: Adaptive OFDM – Channel-dependent scheduling and link adaptation in time and frequency domain
User #3 scheduled
› Uplink: SC-FDMA with dynamic bandwidth (Pre-coded OFDM) – Low PAPR Higher power efficiency – Reduced uplink interference (enables intra-cell orthogonality )
180 k Hz
frequency
› Multi-Antennas, both RBS and terminal – MIMO, antenna beams, TX- and RX diversity, interference rejection – High bit rates and high capacity
frequency
TX
RX
› Flexible bandwidth – Possible to deploy in 6 different bandwidths up to 20 MHz › Harmonized FDD and TDD concept 1.4 – Maximum commonality between FDD and TDD
3
5
FDD-only › Minimum UE capability: BW = 20 MHz
10
15
20 MHz
Half-duplex FDD
fDL
fDL
fUL
fUL
TDD-only
fDL/UL
Figure 1-8: LTE Physical Layer
In contrary to WCDMA the uplink transmissions in LTE are well separated within a cell (intra-cell orthogonality) thanks to the SC-FDMA solution. This leads to a less extensive power control operation. In order to increase the spectrum efficiency, capacity and overall data rates the use of multiple antennas, MIMO (Multiple Input Multiple Output) are included in the standard. With these multiple antennas and advanced signal processing such as spatial multiplexing, the radio channel can be separated into several layers, or “data pipes”. Up to four layers can be utilized. This corresponds to up to four times higher data rates for a given bandwidth.
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LTE/SAE System Overview
3
PROTOCOL STATES AND MOBILITY One of the major simplifications comparing with Rel 6 WCDMA that are made in EPS are in the area of protocol states. While in WCDMA there are four different RRC States defined while being connected (Cell_DCH, Cell_FACH, URA_PCH and Cell_PCH) in LTE there is only one and that is RRC_Connected. As Figure 1-9: Protocol States and Mobility illustrates there are only two RRC States: IDLE and CONNECTED. On the EPC side UE can be either EMM_DEREGISTERED or EMM_REGISTERED. MME
Track ing Area Update (TAU)
Handover
eNB Tracking Area (TA) UE position known on TA level in MME
UE position known on Cell level in eNodeB
Detach, Attach reject, TAU reject
ECM: EPS Connection Management EMM: EPS Mobility Management RRC: Radio Resource Control
Signaling connection establishment
UE position not known in network
ECM-IDLE
PLMN selection
ECM-CONNECTED
RRC_IDLE
RRC_IDLE
EMMDEREGISTERED
RRC_CONNECTE D
Signaling connection release
EMMREGISTERED
Attach accept, TAU accept
Figure 1-9: Protocol States and Mobility
In EPS cells are grouped in Tracking Area (TA) comparing with WCDMA where cells are grouped into Routing Areas (RAs) Location Areas (Las) and UMTS Registration Areas (URAs). Further a single UE can be known on TA list level decreasing signaling load.
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4
QOS HANDLING The LTE Quality of Service (QoS) Handling coordinates and assigns the appropriate QoS to other functions in LTE RAN. The RBS maps QCIs (Quality of Service Class Indicators) to priorities for different Data Radio Bearers (DRBs) in the LTE radio interface and different data flows in the transport network. The LTE QoS Handling complies with the 3GPP Rel 8 QoS concept. It provides service differentiation per user equipment by support of multiple parallel bearers. To provide service differentiation in the uplink, traffic separation must be ensured between the different data flows within the user equipment. This is done by offering an operator-configurable mapping between QCIs and LCGs (Logical Channel Groups, also sometimes referred to as radio bearer groups). Moreover, service differentiation is enabled by mapping of QCIs to priorities as defined in 3GPP TS 23.203. In the uplink, these priorities will serve as a basis for the user equipment to establish differentiation/prioritization between its logical channels. Signalling Radio Bearers (SRBs) are assigned higher priority than Data Radio Bearers (DRBs). SRB1 has higher priority than SRB2. For the UL, the transport network benefits from QoS by mapping QCI to DiffServ Code Point (DSCP) in the RBS. This enables the transport network to prioritize between its different data flows over the S1 interface in the uplink and over the X2 interface for the downlink data in case of Packet Forwarding. For the DL, a similar mapping is performed in the S-GW for the S1 DL data. All QoS class identifiers defined by 3GPP are accepted.
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LTE/SAE System Overview
The figure below shows an overview of the QoS implementation in LTE: QCI
Priority
LCG
DSCP
Pbit
1
2
2
46
5
2
4
1
36
4
: :
: :
: :
:
: :
9
9
3
:
0
10-256
10
3
12
0
IP connectivity
Transport Network QoS PGW IP connectivity
Radio Network QoS Traffic assigned QCI related scheduling priority (1..10)
DSCP IP Header
SGW IP connectivity
Ethernet Header Pbits
eNodeB
Traffic mapped to one of 4 LCGs
QCI mapped to DSCP and Pbits
Figure 1-10: LTE QoS Implementation
QoS Handling is based on mapping QCIs received from the core network to RBS-specific parameters. This makes it possible to have different priorities and DSCP values. The Scheduler is an essential QoS enabler. In the downlink, the Scheduler operates on individual logical channels, with scheduling priorities based on a Round Robin or Proportional Fair scheduling strategy. In the uplink, the scheduling in the RBS operates on Logical Channel Groups (LCGs) using similar scheduling strategies as in the downlink to grant resources. In uplink, the distribution of the granted resources is done per logical channel internally within the user equipment using the rate control function. The RBS maps the QCI to LCG and informs the user equipment about the association of a logical channel to an LCG and the logical channel priority for each logical channel. In the Transport Network the QCI is used to define the Differentiated Services Code Point (DSCP) value that is used in the IP header which in turn is mapped to the Ethernet Priority bit (Pbit) value in the Ethernet frame header. DSCP is used to provide QoS separation in any IP routers in the transport network while Ethernet Pbit is used for QoS separation in Ethernet switches. All this mapping is controlled by the Operator by means of Network parameters Standardized QCIs (1-9) are used according to 3GPP TS 23.203.
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Non-standardized QCIs (10-256) are all given the same priority, which shall be lower compared to priorities for the standardized QCIs. The priority settings enable traffic separation of the different data flows in the RBS. For the uplink, the priorities are sent to the UE, which may differentiate/prioritize between its logical channels. Mapping QCIs to Logical Channel Groups (LCGs) can be configured in OSS-RC and enables traffic separation in the uplink. There are three LCGs (1-3) available. By default, LCG 1 is assigned to all QCIs. Non-standardized QCIs are all given the same configurable DSCP value. From OSS-RC it is possible to control the scheduling strategy (proportional fair or resource fair) per RBS. Multiple RBSs can be configured in parallel from OSS-RC.
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LTE/SAE System Overview
5
SUMMARY The students should now be able to: 1 Explain the background and architecture of E-UTRAN and EPC 1.1 Describe the evolution of cellular networks 1.2 Summarize the evolution of 3GPP releases, from release 99 to release 14 1.3 Explain the logical architecture of EPS and the interworking with other technologies 1.4 Explain the EPS bearer concept and give an overview of the LTE QoS framework Figure 1-11: Summary of Chapter 1
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2 EPC Architecture
Objectives
On completion of this chapter the students will be able to: 2 2.1 2.2 2.3 2.4
Describe the EPC Architecture Describe the interfaces in EPS Describe the Evolved Packet Core (EPC) Describe the role of the MME, S-GW and PDN-GW Describe the S1 (and X2) protocol stacks
Figure 2-1: Objectives of Chapter 2
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LTE/SAE System Overview
1
EPC ARCHITECTURE The responsibilities of the Mobility Management Entity (MME), Home Subscriber Server (HSS), Policy and Charging Rules Function (PCRF), Serving Gateway (SGW) and Packet Data Network Gateway (PGW) EPC nodes are illustrated in the figure below. HSS Responsibilities: • User subscription details • User registration management • Storage of UE security parameters • Maintain knowledge of used PGW
PGW Responsibilities: • QoS Policy Control and Enforcement • Packet Filtering • Charging • IP PoP
Gn
HSS
HSS S10
SGSNMME
SG6
MME
Gx
PGW S5/S8 S11
S1-MME
SGW
S1-U
MME Responsibilities: • UE attach/detach handling • NAS Security • EPS Bearer Handling eNodeB • Mobility Management for Idle Mode UEs • GW Selection • Paging
PCRF
SAPC PCRF:
EPG
Deploys a set of operator-created business rules
SGW Responsibilities: • Local anchor for mobility • Network routing information • Charging for roaming users • Lawful Intercept
Figure 2-2: Evolved Packet Core (EPC)
The figure above also illustrated the hardware that supports these EPC nodes.
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EPC Architecture
1.1
Ericsson VoLTE Architecture The figure below illustrates the nodes and networks that represents the Ericsson implementation of the VoLTE architecture. This is the architecture which is further described in this book. Relevant nodes and interfaces are shown as defined in 3GPP. •
the EPC/LTE network can be in either in the Home or Visited network
•
the MMTel services are always executed in the Home network.
•
the SBG/P-CSCF nodes can be in the visited network for IMS roaming
•
the same HSS is used in both MMTel and LTE/EPC Serving Network
Home Network
S6a Sh
MME S11
S1-MME
HSS MMTel AS
PCRF Gx
Rx
ISC Cx
e-Uu
S1-U
SGi
IR.92
eNodeB
Mw P-CSCF/
S&P GW
I-/SCSCF
IMS AGw
LTE Gm P-CSCF
Mb
IMS AGw
Ut
E-UTRAN
EPC, Evolved Packet Core
EPS, Evolved Packet System
IMS
VoLTE, Voice over LTE
Figure 2-3: LTE/EPC/IMS Architecture
1.2
Mobility Management Entity (MME) The MME handles the mobility and session management functions listed below: UE attach/detach handling This allows UE to register and de-register to the network.
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LTE/SAE System Overview
Security The MME implements functions for Authentication and Authorization to verify users’ identities grant access to the network and track users’ activities, respectively. In addition, the MME performs ciphering and integrity protection of NAS message signaling. EPS Bearer Handling The MME manages the setting up, modification and tearing down of EPS Bearers. It is assumed that a UE in E-UTRAN will always have one default EPS Bearer established at the time of attachment to the network. Mobility Management for Idle Mode UEs The MME manages mobility of idle mode UEs. Idle mode UEs are tracked with the granularity of Tracking Areas (see mobility chapter). There two types of native SGSN-MME hardware supported at the current release. MkVIII and MkX. MkVIII
MkX
(5th generation HW)
(6th generation HW)
vSGSN-MME (High level architecture)
IBENv4 IBTEv4 IBAS/IBACv4 IBS7v4 FSBv4 PEBv4/v5
GEP3 GEP3-HDD/SDD SCXB2 CMXB3 APP GEP3-SS7 (optional)
GEP5 GEP5-SSD SMXB
Figure 2-4: Ericsson SGSN-MME Hardware evolution overview
1.2.1
MKVIII The SGSN-MME MkVIII hardware consists of a cabinet housing one, two, or three magazines where they house various Plug-In Units (PIUs). At the bottom of the cabinet are two Active Patch Panels (APPs), from where the internal cabling connects to all switches in the magazines. All components are accessible and maintained from the front of the cabinet
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Figure below shows the characteristic of the Ericsson SGSN-MME MkVIII.
Processing blades (GEP3, GEP5)
Cabinet (BYB 501)
Ethernet switches (SCXB2 and CMXB3)
Subracks (EGEM2)
WDH: 60*40*180 cm Footprint 0.24 m2 Volume 0.43 m3 Power & Fan Modules (PFMs)
Active Patch Panels (APPs) for external Ethernet connectivity
Figure 2-5: MkVIII hardware
The EGEM2 (Evolved Generic Ericson Magazine 2) houses a high performance backplane for interconnectivity of all the components for the MkVIII hardware. The backplane in an EGEM2 magazine provides the following dual redundant features: •
Power distribution to all slots
•
1 GbE connections to each slot from the System Control Switch Boards (SCXBs)
•
10 GbE connections to slot 1–24 from the Component Main Switch Boards (CMXBs)
•
Intelligent Platform Management Bus (IPMB) used for supervision and management between PIUs.
Each magazine contains two 1 GbE switches (SCXBs) and two 10 GbE switches (CMXBs) that interconnects the slots in the backplane. Processing PIUs, such as the GEP3s are connected to both types of switches through the backplane. All switches are also connected to each other for synchronization purposes.
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LTE/SAE System Overview
The SGSN-MME hardware incorporates functionality for redundancy, hot swap capabilities, and two-step distribution of power. It also complies to worldwide telecom approvals such as for electromagnetic compatibility, earthquake protection, and safety features. Ericsson-standard building practices are applied for easy installation and maintenance. The SGSN-MME 13A on MkVIII hardware provides triple access for GSM, WCDMA and LTE access types. The new hardware platform MkVIII enables scalability from entry level to 10M+ SAU in a single node, to efficiently handle strong market growth of smart phones, mobile broadband and M2M connected devices.
1.2.2
MkX The SGSN-MME MkX hardware consists of a cabinet housing which houses up to three magazines. A magazine contains various Plug-In Units (PIUs). All components are accessible and maintained from the front of the cabinet.
Increased performance and scalability
Increased functionality and flexibility
Cloud evolution and migration
Figure 2-6: SGSN-MME MkX
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Figure below shows the characteristic of the Ericsson SGSN-MME MkX. Ericsson Blade System (EBS) Processing and storage blades (GEP5)
Cabinet (BYB 501)
Ethernet switch blades (SMXB)
Subracks (EGEM2) WDH: 60*40*180 cm Footprint 0.24 m2 Volume 0.43 m3 Power & Fan Modules (PFMs)
Figure 2-7: SGSN-MME MkX Hardware Architecture
The MkX hardware, introduced in the release SGSN-MME 15A, has increased performance and scalability. It provides triple access for GSM, WCDMA and LTE access types. It supports the new GEP5 processing blade introduced instead of the GEP3 processing blade used by MkVIII. It has increased functionality and flexibility. It offers enhanced routing solution enabling new functionality and improved characteristics. SGSN-MME MkX supports cloud evolution and enables the migration to cloud. It is possible to have pool interworking with virtual SGSN-MMEs and it supports a common feature set across native & virtual nodes. Both the MkVIII and MkX platforms are all-IP and only support IP connectivity.
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1.2.3
Virtual SGSN-MME Ericsson’s virtual SGSN-MME is an evolution of the SGSN-MME for native networks. In addition to deployment on purpose built HW (MkVIII or MkX), it is possible to deploy SGSN-MME 16A in a cloud environment.
SGSN Pool Proxy (including Gb/FRGb/IP)
NFV
High performance PNF
High performance VNF
SGSN-MME MkX
vSGSN-MME
Common feature set and development across native & virtual SGSN-MMEs,including support for all access types LTE/3G/2G Pool interworking between native & virtual SGSN-MMEs Smooth and secure migration / transformation to NFV while leveraging previous investments in native nodes
Figure 2-8: vSGSN-MME
The virtual SGSN-MME is based on the same architecture as the physical SGSNMME, including middleware and application software. This provides a common feature set for both physical and virtual SGSN-MME. It also assures interworking between virtual SGSN-MME, physical SGSN-MME, and related peer network elements
1.3
vSGSN-MME Architecture The virtual SGSN-MME is executed in a cloud environment, which consists of the following components:
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•
Cloud infrastructure: The Ericsson CEE or a third-party cloud infrastructure, providing Infrastructure as a Service (IaaS), where the virtual SGSN-MME executes on a cluster of VMs. The CEE supports Ericsson or third-party COTS hardware for compute, storage, and networking. The ECEE is based on OpenStack components, the Kernel-based Virtual Machine (KVM) hypervisor, and the high performance Ericsson Virtual Switch (EVS) based on Open vSwitch (OVS).
•
Cloud management system: the Ericsson ECM or a third-party cloud management system, providing management and orchestration of the virtual resources. The ECM provides
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EPC Architecture
management and orchestration of services running on virtualized resources. It is possible that one ECM serves multiple tenants and applications sharing infrastructure. The ECM supports onboarding and instantiation of virtual applications using the Open Virtualization Format (OVF) package standard. The ECM also supports general-purpose VNF life cycle management, which depending on the use case can substitute or complement parts of the OSS-RC/ENM VNFM functionality. •
Ericsson OSS-RC or Ericsson Network Manager (ENM): providing network and element management of the Ericsson Physical Network Functions (PNFs) and Virtual Network Functions (VNFs). Also, providing a Virtual Network Function Manager (VNFM) for the Ericsson VNFs. It is a Element Manager for both the physical and the virtual SGSN-MME. The virtual SGSN-MME has the same northbound interfaces to OSS-RC/ENM as the physical SGSN-MME. Therefore, both the physical and the virtual SGSN-MME can be managed together in a seamless way, with equal support from OSSRC/ENM
•
Legacy OSS/BSS systems of the operator
Virtual SGSN-MME is deployed in the cloud infrastructure as a cluster of VMs. The VM roles, number of VMs, VM sizes, and VM images are described in the following sections. Example: vGP guest VM
+ Software configurable Traffic Mix Optimization for LTE/3G/2G
2G/3G only
Guest SCTP SS7
CP
UP
Using para-virtualized drivers for networking and disk access (e.g. virtio, vmxnet3)
SGSN-MME middleware
2 vNICs per vGP guest VM for node internal connectivity
Linux + Fast Path Networking
(DPDK accelerated) Virtual Switch (e.g. OVS)
Cloud Infrastructure SW (e.g. OpenStack, libvirt etc)
Linux / KVM or VMware® ESXi™
Virtual Switch performance and characteristics of great importance to the VNFs
Host Hardware (x86 CPU(s), NICs, etc)
Usually 2-4 x 10G pNICs per host machine assigned to LAN and/or SAN, plus redundancy (HW+cloud dependent)
Figure 2-9: vSGSN-MME High level architectural
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1.4
Policy and Charging Rules Function (PCRF) The PCRF is a server that deploys a set of operator-created business rules. These rules define how Network resources should be allocated to subscribers and applications and under what conditions. The PCRF communicates with the PGW over the Gx interface to manage subscriber and network information according to the established rules. The Ericsson Service-Aware Policy Controller (SAPC) supports the PCRF functionality in the EPC. The SAPC application runs on top of Ericsson Telecom Server Platform (TSP 6.0) platform. The TSP 6.0 platform is supported by Ericsson Network Server Platform (NSP) hardware using BYB 501 cabinets.
› PCRF supported by Ericsson SAPC › HSS and SAPC can be built on Native solutions like TSP and BSP or Virtualized within Ericsson Cloud System solution. › TSP is high availability platform (99.99% availability target) › NSP/BSP hardware using BYB 501 › Support for VoLTE and two-sided business models
BSP 8100 / GEP5
› Network Function Virtualization Figure 2-10: PCRF and HSS Nodes
In addition to the classic SAPC development on TSP platform (features above), there is now a parallel track, called eSAPC. The eSAPC is delivered on a new software platform based on the Common Components and supports both EBS and COTS, Commercial-off-the-shelf hardware.
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The vSAPC is a SW-only product, capable of being deployed in Ericsson BSP 8100, 3P HW or Cloud Data Centers
› SAPC 14A, 14B and 15B are based on TSP/NSP. › vSAPC 15A and vSAPC 16A are based on a virtualized architecture. vSAPC 15A can be deployed in non-cloud (node-based) or cloud environments (VNF-based). COTS/EBS HW is supported. › vSAPC 16A is a SW only product that can be deployed either on certified Blade Server Platform (BSP) or validated Commercial Off-TheShelf (COTS) HW configurations. › SAPC 16B can be based on NSP 6.1 or BSP8100. › vSAPC16B supports both Ericsson (EBS) and COTS HW. Figure 2-11: SAPC Classical and Virtual releases
1.5
Home Subscriber Server (HSS) The HSS is the database that holds the subscription information for UE subscribing to the EPS network. The HSS stores, for example, the location of the UE (on MME node level), and authentication parameters. The HSS is an evolution of the Home Location Register (HLR).The HSS application also runs on top of the Ericsson Telecom Server Platform (TSP 6.0) platform.
1.6
Serving Gateway (SGW) The SGW routes the user plane communication from the UE to the PGW. The UE is attached to the same SGW during the complete session. The SGW has the following responsibilities: Local anchor for mobility The SGW acts as a local anchor to support the mobility of UEs between eNodeBs within the SGW service area. Network routing information The SGW is responsible for routing the user plane data to the correct PGW when the UE is attached to the network. Charging for roaming users The SGW is responsible for charging roaming users, the is users connected to another PGW. The user is charged for traffic according to the rate that applies for a particular service, subscription, etc.
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LTE/SAE System Overview
Lawful Intercept This function enables communications to be electronically intercepted, or eavesdropped, by law enforcement agencies, should it be authorized by judicial or regulatory mandates. The SGW is only changed when the UE moves to a new SGW pool area while the PGW is normally kept as long as the UE is attached to the network.
1.7
Packet Data Network Gateway (PGW) The PGW is the gateway between the internal EPS network and external IP Networks, for example, the Internet or a corporate LAN. The UE can be connected to several PGWs simultaneously to access multiple Packet Data Networks. The PGW has the following responsibilities: QoS Policy Control and Enforcement To simplify bearer requests from an application point of view, increase operator’s control over its network resources and limit the potential for abuse by users, EPS QoS is network controlled. The policy control and enforcement functions associate users’ traffic flows with appropriate QoS classes and executes rate policing to prohibit users or flows from exceeding the QoS limits specified in users’ subscription agreements. Downlink (DL) traffic is policed in the PGW whereas Uplink (UL) traffic is policed in the eNodeB. Packet Filtering Filtering of IP packets to/from the external IP Networks. Charging The charging function is responsible for charging the user for its traffic according to the rate that applies for a particular service, subscription, etc. The SGW and the PGW functions can also be shared with the GGSN hardware on the Juniper M-120/M-320 platform. This is referred to as Evolved Packet Gateway (EPG) and allows one node to support GGSN, SGW and PGW functionality. The SGW and PGW functionality is supported from the GGSNMPG 2010A software release onwards.
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EPC Architecture
Some characteristics of the EPG node are given in the figure below. The Evolved Packet Gateway 16B software can be deployed both as native node on SSR 8020 and 8010 hardware and as Virtual Network Function as part of Ericsson virtual Evolved Packet Core solutions
Common components › Common, modular Ericsson IP Operating System › Common switch fabric cards, line cards, service cards › Common route processor and alarm cards Reduced costs › Integration › Maintenance › Sparing
1x100GbE Line Card (SSR)
SSR 8020
SSR 8010
SSC performance enhancement › Capacity increase › User performance support of LTE Advanced
BACKPLANE CAPACITY (HALF-DX)
UP TO 8 TBPS
100 and 400 GBPS
PER-SLOT CAPACIY (FULL-DX) HEIGHT (RU)
UP TO 16 TBPS
21
38
Figure 2-12: EPG 16B platform support
EPG is supported on both the M120/M320 and SSR platforms. Both platforms shall have the same mobile gateway features and all standardized interfaces preserved. Smart Services Router provides superior performance, 10 times better performance such as in throughput, signaling, number of sessions handled, etc. compared to EPG on Juniper.
GERAN AND UTRAN ARCHITECTURE Figure 2-13: Typical Implementation of combined SGSN/MME shows a standardization view on how GERAN, UTRAN and E-UTRAN are integrated into the SAE CN. It should however be noted that the SGSN and MME shares a lot of common functionality. It is also required that the CN protocols, Session Management (SM) and Mobility Management (MM), used in 2G/3G are compatible with the respective protocols used in EPS meaning that the SGSN and MME share a common evolution in the 3GPP standard.
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In a typical implementation/deployment view, it is likely that the 2G/3G SGSN and the MME are merged into one node. This will make it possible to support intra SGSN/MME and inter P/S-GW/GGSN node mobility between the different accesses.
MMESGSN Uu
WCDMA/GSM RAN
Gr
S4
HSS
SGSN S6a
S4
S12
Gn Gn
S-GW
S6 PCRF
S1MME Uu
LTE RAN
MME
Gx
S11
OCS Gy
EPG
S1-U S-GW
PDN
SGi
S5 PDNGW
s2a
S12
S-GW
Trusted non-3GPP access TWAN - Trusted (TWAN) WLAN Access Network
Figure 2-13: Typical Implementation of combined SGSN/MME
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2
MME AND S-GW POOLING It is possible to pool a number of MME and S-GW nodes together in order to eliminate the risk that one node failure will cause parts of the network to be out of service. This is possible since there is a many-to-many relation interface between eNBs and EPC nodes where each eNB is associated with a set of MME and S-GW called an MME and S-GW pool. The resulting network is nonhierarchical. Independent pooling MME and S-GW are supported, it is however not possible to change a S-GW without involving the MME. An operator may pool MMEs and S-GWs into one or several pools depending on organization, regulatory requirements, transport providers etc. (This is illustrated in Figure 2-14). The flexibility of the pooling concept makes it possible to enable partial sharing of networks; i.e., to use only a part of the operator’s network as a shared network. The individual pooled MMEs and S-GWs do not have to be located on the same physical site, but can be distributed in the network. All pools of a particular operator are assumed to be interconnected by means of an interface similar to the S3/S4/S10/S11 interface. When a UE attaches to the network, it is assigned to one of the MMEs that belong to the MME pool associated with the eNB through which the UE is attaching, the MME then selects an S-GW in the S-GW pool. No change of MME or S-GW is required while the UE moves around among eNBs belonging to the same MME or S-GW pool. If the UE moves out of the pools coverage it is reassigned to an MME or S-GW in the pool associated with the new eNB. The P-GW who performs charging, policy enforcement and UE’s IP PoP (Point of Presence) is not changed when the S-GW is relocated. The main purpose of the S-GW is to act as a local mobility anchor and to buffer packets during E-UTRAN paging. In Ericsson view S-GW will be rare and in most case the S-GW and PGW is performed by the same physical node. MME relocation may be more motivated since there may be limits on how many eNBs the MME is connected to.
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LTE/SAE System Overview
Figure 2-14 below shows an example of when pooling is used. Before: S+P-GW After: P-GW only
SGW
MME MME S10 MME MME MME IP PoP PGW S5 SGW SGW SGW SGW
1
S-GW
MME MME MME MME MME SGW
SGW
SGW
2
› MME relocation occurs primarily only when moving between MME Pool Areas. – With well-designed MME Pool Areas, this is a rare case. – With a 1:1 relation with MME Pool : SGW Service area the same applies to SGW Relocation
› The IP Point of Presence (IP PoP) is fixed in the originally selected PDN GW › At Inter-pool/SGW Service Area mobility => two GWs in the user plane (SGW & PGW)
Figure 2-14: MME Pooling - Moving between pools
Partially overlapping pools will also be supported. Overlapping pools may have some benefits since it makes it possible to avoid some of the negative effects of hard pool borders, however it comes with extra complexity.
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3
OVERVIEW SAE/LTE INTERFACES This section contains a brief overview of the SAE/LTE interfaces.
MME
S1-M
Uu
S-GW
S11
S5/S8
PDN-GW
eNodeB
UE
NAS RRC PDPC RLC MAC L1
RRC PDPC RLC MAC L1
Relay
NAS S1-AP SCTP IP L2 L1
S1-AP SCTP IP L2 L1
Relay
Relay
GTPv2-C
GTPv2-C
GTPv2-C
GTPv2-C
UDP IP L2 L1
UDP IP L2 L1
UDP IP L2 L1
UDP IP L2 L1
Figure 2-15: LTE/EPC Control Plane
S1-U
Uu
S5/S8
PDN-GW
SGi
eNodeB
UE
Application IP PDPC RLC MAC L1
S-GW
PDPC RLC MAC L1
Relay
GTPv1-U UDP/IP L2 L1
GTPv1-U UDP/IP L2 L1
Relay
GTPv1-U UDP/IP L2 L1
IP GTPv1-U UDP/IP L2 L1
Figure 2-16: LTE/EPC User Plane
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LTE/SAE System Overview
PDN GW (PCEF)
Gx
Diameter TCP IP L2 L1
SAPC (PCRF)
Diameter TCP IP L2 L1
Figure 2-17: Basic EPC architecture – Gx interface
The figures below contain a brief overview of the SAE/LTE interfaces.
Figure 2-18: Basic EPC architecture – Rx interface
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SBG/ P-CSCF
SGi
PDN-GW
SBG/ P-CSCF
SGi
PDN-GW
User Data SIP UDP/TCP
RTP
UDP/TCP
UDP/TCP UDP
UDP/TCP UDP
IP
IP
IP
IP
L2
L2
L2
L2
L1
L1
L1
L1
Figure 2-19: Basic EPC architecture – SGi interface
Gm
S-GW
S1-U
Uu
S5/S8
SGi
PDN-GW
SBG/ P-CSCF
eNodeB
UE
SIP
SIP
UDP/IP
UDP/IP Relay
PDPC RLC
PDPC RLC
MAC
MAC
L2
L2
L1
L1
L1
L1
GTPv1-U UDP/IP
GTPv1-U UDP/IP
Relay
GTPv1-U UDP/IP
UDP/IP
UDP/IP
L2
L2
L1
L1
L2 L1
L2 L1
GTPv1-U UDP/IP
Figure 2-20: Basic MMTel architecture – Gm interface
3.1
Uu Interface Uu is the interface between the UE and the eNodeB. The control plane signaling is covered by the RRC protocol (Radio Resource Management). RRC can also carry NAS messages (signaling messages between the UE and the MME). RRC is carried by PDCP, RLC and MAC. The user plane is carried by PDCP, RLC and MAC.
3.2
S1 Interface S1 S1 is the interface between eNBs and MME and S-GW. In the user plane this interface will be based on GTP User Data Tunneling (GTP-U) (similar to today’s Iu and Gn interface). In the control plane the interface is more similar to Radio Access Network Application Part (RANAP), with some simplifications and changes due to the different functional split and mobility within EPS. It has been agreed to split the S1 interface into a S1-CP (control) and S1-UP part (user plane). The signaling transport on S1-CP will be based on SCTP (Streaming Control Transmission Protocol). The signaling protocol for S1 is called S1-AP (Application Protocol).
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S1-AP protocol has the following functions: EPS Bearer management function This overall functionality is responsible for setting up, modifying and releasing EPS bearers, which are triggered by the MME The release of EPS bearers may be triggered by the eNB as well. Initial Context Transfer function This functionality is used to establish an S1UE context in the eNB, to setup the default IP connectivity, to setup one or more SAE bearer(s) if requested by the MME, and to transfer NAS signaling related information to the eNB if needed. Mobility Functions for UEs in LTE_ACTIVE in order to enable - a change of eNBs within SAE/LTE (Inter MME/S-GW Handovers) via the S1 interface (with EPC involvement). - a change of RAN nodes between different RATs (Inter-3GPP-RAT Handovers) via the S1 interface (with EPC involvement). Paging: This functionality provides the EPC the capability to page the UE. S1 interface management functions: - Reset functionality to ensure a well-defined initialization on the S1 interface. - Error Indication functionality to allow a proper error reporting/handling in cases where no failure messages are defined. - Overload function to indicate the load situation in the control plane of the S1 interface. NAS Signaling transport function between the UE and the MME is used: - to transfer NAS signaling related information and to establish the S1 UE context in the eNB. - to transfer NAS signaling related information when the S1 UE context in the eNB is already established. S1 UE context Release function This functionality is responsible to manage the release of UE specific context in the eNB and the MME. S1 is a many-to-many interface.
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3.3
X2 Interface X2 is the interface between eNBs. The interface is mainly used to support active mode UE mobility (Packet Forwarding). This interface may also be used for multi-cell Radio Resource Management (RRM) functions. The X2-CP interface consists of a signaling protocol called X2-AP on top of SCTP. The X2-UP interface is based on GTP-U. The X2-UP interface is used to support loss-less mobility (packet forwarding). The X2-AP protocol provides the following functions: Mobility Management. This function allows the eNB to move the responsibility of a certain UE to another eNB. Forwarding of user plane data is a part of the mobility management. Load Management. This function eNBs to indicate overload and traffic load to each other. Reporting of General Error Situations. This function allows reporting of general error situations, for which function specific error messages have not been defined. The X2 interface is a many-to-many interface.
3.4
Other EPS Interfaces Gi Gi is the interface to external packet data networks (e.g., Internet) and contains the end-user’s IP point of presence. All user- and control-plane functions that use the Gi interface are handled above the end-user’s IP layer. All terminal mobility within 3GPP will be handled below the Gi interface. S3 S3 is a control interface between the MME and 2G/3G SGSNs. The interface is based on Gn/GTP-C (SGSN-SGSN), possibly with some new functionality to support signaling free idle mode mobility between E-UTRAN and UTRAN/GERAN. S3 will not support packet forwarding; instead this will be supported on the S4 interface. S3 is a many-to-many interface. The S3 interface is similar to the S10 interface between MMEs which will be used for intra-LTE mobility between two MME pool areas. S4 S4 is the interface between the P-GW and 2G/3G SGSNs. The interface is based on Gn/GTP (SGSN-GGSN). The user plane interface is based on GTP-U (same as S1-UP and Iu-UP) and the control plane is based on GTP-C (similar to S11). S4 is a many-to-many interface.
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LTE/SAE System Overview
The S4 interface is backwards compatible with the Gn interface. S6 S6a enables transfer of subscription and authentication data for authenticating/authorizing user access to the evolved system (AAA interface) between MME and HSS. S6d is between the SGSN and the HSS. S6 is based on Diameter. S5/S8 S5/S8 is the interface between the S-GW and P-GW. In principle S5 and S8 is the same interface, the difference being that S8 is used when roaming between different operators while S5 is network internal. The S5 / S8 interface will exist in two flavors one based on Gn/GTP (SGSN-GGSN) and the other will use the IETF specified Proxy Mobile IP (PMIP) for mobility control with additional mechanism to handle QoS. The usage of PMIP or GTP on S5/S8 will not be visible over the S1 interface or in the terminal. In the non roaming case the S-GW and P-GW functions can be performed in one physical node. It has been agreed in 3GPP that the usage of PMIP or GTP on S5 and S8 should not impact RAN behavior or impact the terminals. S5 / S8 is a many-to-many interface. In the roaming case S8 is providing user and control plane between the Serving GW in the VPLMN and the PDN GW in the HPLMN. S8 is the inter PLMN variant of S5. S9 S9 provides transfer of (QoS) policy and charging control information between the Home PCRF and the Visited PCRF in order to support local breakout function. S10 S10 is a control interface between the MMEs which will be very similar to the S3 interface between the SGSN and MME. The interface is based on Gn/GTP-C (SGSN-SGSN) with additional functionality. S10 is a many-to-many interface. S11 S11 is the interface between the MME and S-GW. The interface is based on Gn/GTP-Control (GTP-C) (interface between SGSN-GGSN) with some additional functions for paging coordination, mobility compared to the legacy Gn/GTP-C (SGSN-GGSN) interface. S11 is a many-to-many interface.
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S12 S12 is the interface between UTRAN and Serving GW for user plane tunneling when Direct Tunnel is established. It is based on the Iu-u/Gn-u reference point using the GTP-U protocol as defined between SGSN and UTRAN or respectively between SGSN and GGSN. Usage of S12 is an operator configuration option. S13 S13 enables UE identity check procedure between MME and EIR. SGi SGi is the interface between the PDN GW and the packet data network. Packet data network may be an operator external public or private packet data network or an intra operator packet data network, e.g. for provision of IMS services. This interface corresponds to Gi for 3GPP accesses. Sx Sx in an Ericsson interface which interconnects MME and SAPC (PCRF in Ericsson). It allows to introduce Mobility Based Policy decreasing the signaling load in EPC. Rx Rx is the interface between the application server and the PCRF Gx Gx provides transfer of (QoS) policy and charging rules from PCRF to Policy and Charging Enforcement Function (PCEF) in the PDN GW.
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LTE/SAE System Overview
4
EVOLVED IP NETWORK SOLUTION Ericsson offers EIN to smoothly interconnect the network nodes. EIN Provides the IP transport solution Including IP security, synchronization, Quality of Service etc. The Evolved IP Network solution (EIN) provides an IP transport foundation for multi-service broadband offerings. It is based on Ericsson’s broad portfolio of IP, microwave and optical and network management products. It’s continually developed and enhanced, and supported by Ericsson Global Services.
Figure 2-21: Evolved IP network solution composition
IP transport infrastructure plays a key role in meeting subscriber expectations for reliability and superior performance. An effective end-to-end network will keep up with rapidly evolving technology and standards, new user devices and demanding subscriber requirements.
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EPC Architecture
At the same time, an operator requires IP network flexibility to facilitate multiservice capabilities, continued capacity and coverage expansion, and to deliver attractive and cost-effective new services. Multi-access
Multimedia traffic High Availability
2G 3G 4G WiFi
Network Management
Mobile
Mobility
Residential
Video
Gaming
Performance Management QoS WWW
Security Enterprise
Synchronization Voice telephony
End-to-End solution attributes
Music
Figure 2-22: EIN solution Attributes
End-to-End means providing IP/MPLS transport from the access networks to the packet gateway connections to external networks
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LTE/SAE System Overview
5
SUMMARY The students should now be able to: 2 2.1 2.2 2.3 2.4
Describe the EPC Architecture Describe the interfaces in EPS Describe the Evolved Packet Core (EPC) Describe the role of the MME, S-GW and PDN-GW Describe the S1 (and X2) protocol stacks
Figure 2-23: Summary of chapter 2
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Intentionally Blank
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E-UTRAN Architecture
3 E-UTRAN Architecture
Objectives On completion of this chapter the students will be able to: 3 Describe the E-UTRAN Architecture 3.1 List the functionality of the eNodeB 3.2 Describe the radio interface techniques, OFDM/SC-FDMA and the physical bit rates 3.3 Discuss Link Adaption in LTE 3.4 Describe the basic principles of MIMO 3.5 Explain the concept of Advanced Carrier Aggregation 3.6 Describe the RBS 6000 Hardware for LTE 3.7 Describe the Ericsson Radio System 3.8 Explain Heterogeneous Network 3.9 Outline on overview level the security in LTE 3.10 Describe the different type of synch in LTE Figure 3-1: Objectives of Chapter 3
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1
INTRODUCTION The radio interface in LTE is developed according to the requirements of spectrum flexibility, spectrum efficiency, cost effectiveness etc. Robustness against time dispersion has influenced the choice of transmission technique in both UL and DL. Spectrum flexibility incorporates the possibility of using both paired and unpaired spectrum, i.e. LTE should support both FDD- and TDD-based duplex arrangements, respectively. Also, the support for operation in six different bandwidths, 1.4, 3, 5, 10, 15 and 20 MHz, plays an important role in the spectrum flexibility part in the standardization of the radio interface. Actually, the LTE radio interface implementation supports operation in any bandwidth between 1.4 and 20 MHz in steps of one resource block, which corresponds to 12 subcarriers or 180 kHz. A high spectrum efficiency is achieved by the use of higher order modulation schemes, like 16-QAM, 64-QAM and 256-QAM and advanced antenna solutions, including transmit- and receiver diversity, beam forming and spatial multiplexing (MIMO). Furthermore, the Inter-symbol Interference (ISI) is reduced by the choice of OFDM in the DL and SC-FDMA in UL. Both of these methods results in a long symbol time and thus a reduced ISI, which increases the performance in highly time dispersive radio environments. The UL and DL have a similar time-domain structure.
1.1
eNB functionality E-UTRAN consists solely of the evolved Node B (eNB), which is responsible for all radio interface functionality. eNB is the RAN node in the EPS architecture that is responsible for radio transmission to and reception from UEs in one or more cells. The eNB is connected to EPC nodes by means of an S1 interface. The eNB is also connected to its neighbor eNBs by means of the X2 interface. Some significant changes have been made to the eNB functional allocation compared to UTRAN. Most Rel-6 RNC functionality has been moved to the E-UTRAN eNB.
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A description of the functionality provided by eNB is given in Figure 3-2 below. eNodeB Responsibilities: ›
Cell control and MME pool support
›
Mobility control
›
Control and User Plane security
›
Shared Channel handling
›
Segmentation/Concatenation
›
HARQ
›
Scheduling
›
Multiplexing and Mapping
›
Physical layer functionality
›
Measurements and reporting
RBS 6000 S1-C S1-U
eNodeB
X2
eNodeB
EUTRAN
LTE Uu UE
Figure 3-2: Evolved UTRAN (EUTRAN)
Cell control and MME pool support eNB owns and controls the radio resources of its own cells. Cell resources are requested by and granted to MMEs in an ordered fashion. This arrangement supports the MME pooling concept. S-GW pooling is managed by the MMEs and is not really seen in the eNB. Mobility control The eNB is responsible for controlling the mobility for terminals in active state. This is done by ordering the UE to perform measurement and then performing handover when necessary. Control and User Plane security The ciphering of user plane data over the radio interface is terminated in the eNB. Also the ciphering and integrity protection of RRC signaling is terminated in the eNB. Shared Channel handling Since the eNB owns the cell resources, the eNB also handles the shared and random access channels used for signaling and initial access.
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LTE/SAE System Overview
Segmentation/Concatenation Radio Link Control (RLC) Service Data Units (SDUs) received from the Packet Data Convergence Protocol (PDCP) layer consist of whole IP packets and may be larger than the transport block size provided by the physical layer. Thus, the RLC layer must support segmentation and concatenation to adapt the payload to the transport block size. HARQ A Medium Access Control (MAC) Hybrid Automatic Repeat reQuest (HARQ) layer with fast feedback provides a means for quickly correcting most errors from the radio channel. To achieve low delay and efficient use of radio resources the HARQ operates with a native error rate which is sufficient only for services with moderate error rate requirements such as, for instance, VoIP. Lower error rates are achieved by letting an outer Automatic Repeat reQuest (ARQ) layer in the eNB handle the HARQ errors. Scheduling A scheduling with support for QoS provides for efficient scheduling of UP and CP data. Multiplexing and Mapping The eNB performs mapping of logical channels on to transport channels. Physical layer functionality The eNB handles the physical layer such as scrambling, Tx diversity, beam forming processing and OFDM modulation. The eNB also handles layer one functions like link adaptation and power control. Measurements and reporting eNB provides functions for configuring and making measurements on the radio environment and eNB-internal variables and conditions. The collected data is used internally for RRM but can be reported for the purpose of multi-cell RRM.
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2
LTE AIR INTERFACE The 3GPP has chosen Orthogonal Frequency Division Multiplex (OFDM) as the air interface for downlink (eNodeB to UE) and Single Carrier Frequency Division Multiple Access (SC-FDMA) for the uplink (UE to eNodeB). Both of these access techniques use a combination of frequency and time division multiple access.
2.1
OFDMA/SC-FDMA Frequency Domain As in all data communications the bitrate is proportional to the bandwidth and Signal to Noise ratio (S/N). For a fixed bandwidth the higher the S/N the higher is the possible throughput. The S/N ratio across the RF spectrum as seen by each UE can be quite different. In this example the S/N is high for one user and low for the other on the same frequency, in reality the S/N for Ue:s has no such dependency. The figure below highlights the OFDM symbol in the time and frequency grid and the OFDMA access. In the uplink we have SC-FDMA. User #1 scheduled
Δf=15kHz
User #2 scheduled
› Downlink: Adaptive OFDM/OFDMA – Channel-dependent scheduling and link adaptation in time and frequency domain
User #3 scheduled
OFDMA › Uplink: SC-FDMA with dynamic bandwidth (Pre-coded OFDM) – Low PAPR Higher power efficiency – Reduced uplink interference (enables intra-cell orthogonality ) – Channel-dependent scheduling and link adaptation in time and frequency domain
frequency
180 kHz
frequency
OFDM
Figure 3-3: LTE Physical Layer
With OFDMA and SC-FDMA the RF spectrum is divided up into 15 kHz subcarriers as illustrated above. These are allocated to UEs in groups of 12 known as Resource Blocks (RBs). The LTE specifications support a number of Channel Bandwidths ranging from 1.4 to 20 MHz.
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LTE/SAE System Overview
This is illustrated in the figure below. Channel Bandwidth [MHz] Transmission Bandwidth Configuration [RB]
Channel edge
Resource block
Channel edge
Transmission Bandwidth [RB]
DC carrier (downlink only)
Active Resource Blocks Channel Bandwidth [MHz] Number of Resource Blocks
1.4
3
5
10
15
20
6
15
25
50
75
100
Figure 3-4: LTE Channel Bandwidth
The Direct Current (DC) carrier in the centre of the bandwidth along with a number at the channel edge are not used leaving the number of active RBs ranging from 6 to 100 as illustrated in the figure above. The highest LTE is achieved with the 100 RBs available using 20 MHz Channel Bandwidth. The fact that there are several LTE Channel Bandwidths supported makes the deployment of LTE possible in areas of limited RF spectrum.
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2.2
OFDMA/SC-FDMA Time Domain All radio transmissions are subjected to multiple reflections, diffractions and attenuations caused by natural objects (buildings, hills etc) resulting in what is known as ‘Multipath Propagation’ as illustrated in Figure 3-5 below.
RRC_ CONNECTED
‘Delay Spread’ is 1-2 µs in urban/suburban and up to 20 µs in hilly areas Symbol duration < Delay Spread => Inter Symbol Interference (ISI) Overcome with RAKE Receiver or Equalizer in WCDMA and GSM LTE Symbol duration >Delay Spread and Cyclic Prefix (CP) is used Figure 3-5: RF Multipath Propagation
The energy for a single symbol (or bit) is split between the various paths and arrives at different time intervals. The delay between these various arrivals, known as ‘Delay Spread’ is typically 1-2 µs in urban and suburban areas and up to 20 µs in hilly areas as illustrated in Figure 3-5 above. If the symbol duration is less than the delay spread late arrival of previous symbols causes what is known as ‘Inter Symbol Interference’ (ISI). In WCDMA and GSM this is overcome using sophisticated receiver techniques like the RAKE receiver and equalizer. To keep the cost of LTE terminals low it was decided to use a symbol duration greater than the Delay Spread and to include something known as a ‘Cyclic Prefix’ (CP).
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LTE/SAE System Overview
LTE uses the same 10 msec Radio Frame duration as WCDMA sub-divided into ten 1 msec sub-frames with each of these further sub-divided into 14 symbols as illustrated in Figure 3-6 below.
10 msec Radio Frame Resource Block 1 msec Sub-fame carries 14 symbols Sub-carrier #1
Sub-carrier #12 A CP > Delay Spread will completely remove ISI as the receiver sees each reflection is seen as the same symbol
≈ 71.4 µs
CP ≈ 4.7 µs
Symbol ≈ 66.7 µs
Figure 3-6: OFDMA/SC-FDMA (Time Domain)
A closer look at each symbol which has a duration approximately 71.4 µs shows that the symbol itself is actually only 66.7 µs which is still much longer than the greatest delay spread expected for LTE. This leaves approximately 4.7 µs which is used for the Cyclic Prefix (CP) which is copy of the last part of the symbol as illustrated in Figure 3-6 above. Having the CP longer than the delay spread will completely remove ISI since each reflection is seen by the receiver as the same symbol. This normal CP of 4.7 µs will completely remove ISI in urban and suburban environments. There are also extended CPs of 16.7 μs and 33.3 μs specified by the 3GPP to cope with greater delay spreads in other environments.
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2.3
Adaptive Modulation The type of modulation used in LTE depends on the radio environment. The UE estimates the quality in the downlink and signals it back to the eNodeB in the Channel Quality Indicator (CQI). The uplink reference signals that are embedded into the uplink transmission are used by the eNodeB to estimate the quality in the uplink. The eNodeB decides which modulation technique should be used based on the quality of the downlink and uplink radio environment. LTE supports the following modulation techniques in the downlink and uplink.
•
256 Quadrature Amplitude Modulation (256 QAM) which uses 256 different quadrature and amplitude combinations to carry 8 bits per symbol (DL only)
•
64 Quadrature Amplitude Modulation (64 QAM) which uses 64 different quadrature and amplitude combinations to carry 6 bits per symbol
•
16 Quadrature Amplitude Modulation (16 QAM) which uses 16 different quadrature and amplitude combinations to carry 4 bits per symbol
•
Quadrature Phase Shift Keying (QPSK) which used 4 different quadratures to send 2 bits per symbol.
Adaptive modulation is illustrated below in the figure below:
Radio Environment: Poor
Good
RRC_ CONNECTED
QPSK (2 bits/symbol)
RRC_ CONNECTED
16 QAM (4 bits/symbol)
64 QAM (6 bits/symbol)
RRC_ CONNECTED
256-QAM 8 bits/symbol
eNodeB Figure 3-7: Adaptive Modulation
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LTE/SAE System Overview
As illustrated in the figure above QPSK modulation is used in poor radio environments yielding the lowest throughput. As the environment improves 16 or 64 QAM may be used increasing the throughput and finally in a good radio environment 256 QAM may be used yielding the highest throughput.
2.4
Adaptive Coding To check if the data has been received correctly the transmitter adds a 24-bit CRC to each block of user data before it is passed through a Turbo Coder. The Turbo Coder adds extra ‘parity bits’ to enable the receiver to recover bit errors introduced by the air interface. The more parity bits sent the greater the protection against bit errors but at the expense of the user data rate. Based on the quality of the radio environment these parity bits can be punctured or removed reducing the protection but increasing the user data rate. The eNodeB will adapt the coding rate to suit the radio environment. For example in poor radio environments a low coding rate which contains more parity than systematic bits and offers a high protection against bit errors would be used. On the other hand when the radio environment is high a coding rate which contains more systematic than parity bits could be used offering lower protection but higher user data rate as illustrated in Figure 3-8.
Radio Environment: Poor
Systematic Bit
Good
RRC_ CONNECTED
Parity Bit
RRC_ CONNECTED
Low data rate/ high protection
high data rate/ low protection
eNodeB
Figure 3-8: Adaptive Coding
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The eNodeB will adapt the modulation and coding rate to offer the UE the best possible data rate in various radio environments while maintaining an adequate Bit Error Rate (BER).
2.5
Multiple Input Multiple Output (MIMO) The LTE specifications support the use of Multiple Input Multiple Output (MIMO) techniques using multiple antennas at the eNodeB and UE. In the first releases of LTE the eNodeB is equipped with two transmit antennas and the UE with two receive antennas. In a poor ratio environment, the both eNodeB antennas may be used to send the same data to improve reception at the UE. In this instance the MIMO technique used is ‘Transmit Diversity’ as illustrated in Figure 3-9 below.
Radio Environment:
User data bits
Poor
Good
RRC_ CONNECTED
RRC_ CONNECTED
Ant A 1 2 3 4 5 6 7 8 Ant B 1 2 3 4 5 6 7 8
TX Diversity => Improved reception
Layer1 Layer2
Ant A
Ant B
1 2 3 4 5 6 7 8 9 1011 1213 14 1516
Spatial Multiplexing => Increased Throughput
eNodeB
Figure 3-9: MIMO Techniques
In a good environment each eNodeB transmit antenna may be used to carry different data streams to the UE. In this instance the MIMO technique used is ‘Spatial Multiplexing’ which increases the throughput as illustrated in Figure 3-9 above. Theoretically, we can then multiply this data rate by the number of MIMO layers used 2x2 as in this example or 4x4 which uses 4 transmit and receive antennas. Since the UE has only a single transmit antenna MIMO is not used in the uplink.
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LTE/SAE System Overview
2.6
LTE Scheduling The principle behind downlink scheduling in LTE is to allocate UEs the RBs that have the highest S/N ratio and hence can use the highest order modulation, least coding and MIMO spatial multiplexing. Scheduling in this way gives the most efficient use of the RF spectrum. In the illustration in Figure 3-10 below two users are sharing the available channel bandwidth with both scheduled to use the RBs with the best S/N every 1 msec.
Downlink
Uplink User 1 User 2
=> Low PAPR
User #1 scheduled User #2 scheduled
Users allocated RBs with the Highest S/N
=>
User 1
User 3
User 2
User 4
RRC_ CONNECTED
Low battery consumption
Users allocated ‘Single Carrier’
Figure 3-10: LTE Scheduling
To minimize the Peak to Average Power Ratio (PAPR) of the UE transmitter and thus reduce battery consumption the UE is only scheduled on consecutive RBs in the uplink. From the UE’s perspective the frequency allocation is seen as a single carrier, thus giving the term Single Carrier Frequency Division Multiple Access (SC-FDMA) used to describe the LTE uplink access technique as illustrated in Figure 3-10 above.
2.7
Downlink Physical Bit Rates Since there are 12 sub-carriers per Resource Block (RB) and 14 symbols per subframe the downlink can transmit (12X14) 168 symbols every msec for each RB in the system bandwidth.
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The figure below presents the LTE Downlink Physical rates. 10 msec
168 168 168 168 168 168 168 168 168 168 Frequency
1.4 MHz BW => 6 RBs 3 MHz BW => 16 RBs 5 MHz BW => 25 RBs 10 MHz BW => 50 RBs 15 MHz BW => 75 RBs 20 MHz BW => 100 RBs
168 168 168 168 168 168 168 168 168 168 Eg 168 X 10 X 100 = 168000 symbols in 10 msec = 16.8 Msps = 100.8 Mbps using 64 QAM and 201.6* Mbps using 64 QAM and MIMO * User rate will be less due to signaling and adaptive coding overhead Figure 3-11: LTE Downlink Physical Rates
The number of RBs available depends on the System bandwidth ranging from 6 RBs in 1.4 MHz to 100 in 20 MHz. The highest physical bit rate will be achieved using the 20 MHz system bandwidth with 64 QAM modulation and MIMO spatial multiplexing. This produces a peak physical bit rate of 201.6 Mbps as calculated in the figure above. The user bit rate will be less than 201.6 Mbps due to signaling and adaptive coding overheads.
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LTE/SAE System Overview
The figure below presents others possible Physical Rates for LTE.
Advanced Carrier Aggregation
› Higher throughput can be reached with different features combination.
and MIMO Combination
› 150 Mbps › 300 Mbps
+
› 450 Mbps › 600 Mbps ›… Figure 3-12: Downlink Throughput
2.8
Carrier Aggregation Carrier aggregation is introduced in 3GPP rel10 in order to increase the bandwidth, and thereby increase the bitrate and capacity. Carrier aggregation can be used for both FDD and TDD. Each aggregated carrier is referred to as a component carrier, CC. The component carrier can have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of five component carriers can be aggregated according to 3GPP, hence the maximum aggregated bandwidth is 100 MHz. The individual component carriers can also be of different bandwidths. › Inter-band (carriers on different frequency bands). Band B
Band A
› Non contiguous Intra-band CA (component carriers within the same operating frequency band with uncoordinated spectrum in-between them). Band A
› Contiguous Intra-band CA (component carriers within the same operating frequency band fulfilling the nominal channel spacing requirements). Band A
Figure 3-13: Contiguous Intraband CA
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The figure below summarizes the Carrier Aggregation feature.
› Included functions – 3CC DL Carrier Aggregation Extension – Carrier Aggregation – Carrier Aggregation FDD-TDD – DL 4CC Carrier Aggregation – [New] – Dynamic SCell Selection for Carrier Aggregation – Supplementary Downlink for Carrier Aggregation – Uplink Carrier Aggregation
Figure 3-14: Carrier Aggregation
A way to arrange aggregation would be to use contiguous component carriers within the same operating frequency band (as defined for LTE), so called intraband contiguous. This might not always be possible, due to operator frequency allocation scenarios. For non-contiguous allocation it could either be intra-band, i.e. the component carriers belong to the same operating frequency band, but have a gap, or gaps, in between, or it could be inter-band, in which case the component carriers belong to different operating frequency bands. The main benefit of non-contiguous intraband CA support is to allow the customer to aggregate scattered spectrum in a band as well as allowing spectrum from different bands. “4 Component Carrier Downlink Carrier Aggregation Extension” is a function in the “Carrier Aggregation” available from L17A. It enables an operator to aggregate 4 carriers and a total of up to maximum 80 MHz of spectrum to be configured per device. It is possible to use 4 component carriers together with 256 QAM modulation and 2 or 4 layer MIMO per frequency. A total of 10 MIMO layers is supported in L17A which can provide peak rates of up to 1 Gbps. Carrier aggregation not only enables higher peak rates, it can also be used to extend DL coverage of high frequency bands by aggregation of lower frequency bands.
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LTE/SAE System Overview
The figure below presents the 4-Carrier Aggregation feature. 4CC - Carrier Aggregation
› Description
– Carrier aggregation provides the ability to transmit data to a single UE on multiple carriers simultaneously – Introduces support for carrier aggregation for up to 80 MHz using 4 DL component carriers › Mix of 2/4 layer MIMO and 256 QAM - 4 carriers with 4x2/2x2MIMO (total 8 MIMO layers) is supported › All component carriers must be connected to a common Baseband or in an Elastic RAN configuration
› Operator benefit – Carrier Aggregation enables an operator to offer significantly increased downlink speed across the coverage area – More efficient use of scattered spectrum – Beat competition on end user experience
Figure 3-15: DL 4CC Carrier Aggregation
1 UL & 2 DL CCs
CA UE with 2C CA
1 UL & 3 DL CCs
CA UE with 3C CA 1 UL & 1 DL CCs
UE without CA 1 UL & 4 DL CCs
CA UE with 4C CA
Peak rates of up to 1 Gbps Figure 3-16: 4CC DL Carrier Aggregation Extension – FDD/TDD
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The figure below presents the 5-Carrier Aggregation feature. 5CC - Carrier Aggregation
› Description – Introduces support for carrier aggregation for up to 100 MHz using 5 DL component carriers › Mix of 4x2 and 2x2 MIMO and 256 QAM on all carriers › All component carriers must be connected to a common Baseband 5212/5216 or in an Elastic RAN configuration › Up to 1.0 Gbps per UE using 20 MHz carriers and BB 5216
› Operator benefit – Carrier Aggregation enables an operator to offer significantly increased downlink speed across the coverage area – More efficient use of scattered spectrum – Beat competition on end user experience
Figure 3-17: DL 5CC Carrier Aggregation
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LTE/SAE System Overview
2.9
Uplink Physical Bit Rates In the first releases of LTE UEs do not support 64 QAM modulation or MIMO transmission in the uplink giving the slightly less peak physical bit rate of 67.2 Mbps. This is illustrated in Figure 3-18 below.
10 msec
168 168 168 168 168 168 168 168 168 168 1.4 MHz BW => 6 RBs Frequency
3 MHz BW => 16 RBs 5 MHz BW => 25 RBs 10 MHz BW => 50 RBs 15 MHz BW => 75 RBs 20 MHz BW => 100 RBs
168 168 168 168 168 168 168 168 168 168 Eg 168 X 10 X 100 = 168000 symbols in 10 msec = 16.8 Msps = 67.2 Mbps using 16 QAM * User rate will be less due to signaling and adaptive coding overhead Figure 3-18: LTE Uplink Physical Bit Rates
As in the downlink the user bit rate will be less than 67.2 Mbps due to signaling and adaptive coding overheads.
2.10
Carrier Aggregation in uplink In Rel 12 the UL- Carrier Aggregation Enhancements supports 2CC uplink carrier aggregation up to 40MHz
2.11
Reference Signals The majority of the signaling overhead in the uplink and downlink is attributed to ‘Reference Signals’. Each Downlink RB carries 8 Reference Signals separate in frequency and time in every sub-frame that are known by the UE as illustrated in Figure 3-19 below. The UE measures the Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) which are used for mobility. Based on the RSRQ the UE can calculate the Channel Quality Indicator (CQI) of all RBs and report it back to eNodeB scheduler. Based on this the eNodeB can decide on the modulation and coding that is used.
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The figure below presents the LTE Reference Signals.
Downlink Reference Signals
UE Measures: - Reference Signal Received Power (RSRP) - Reference Signal Received Quality (RSRQ) Used for mobility Uplink Demodulation Reference Signals
Used by the eNodeB for synchronization of the uplink Figure 3-19: LTE Reference Signals
Every 1 msec each uplink RB also carries 24 Demodulation Reference Signals as illustrated in Figure 3-19 above. These are used as a training sequence to synchronize the uplink transmission so that it can be demodulated by the eNodeB in the same way as pilot bits are used in WCDMA. The 3GPP also specify ‘Sounding Reference Signals (SRS) for the uplink which are not associated with uplink data transmission and are used mainly for channel quality determination if channel dependent scheduling is used.
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LTE/SAE System Overview
2.12
Lean Carrier Significant reduction of Reference Symbols in Downlink Ericsson Lean Carrier:
Ericsson Lean Carrier:
Current LTE reference User Data signaling causes Throughput interference between cells
Ericsson Lean Carrier User Data dynamically reduces Throughput reference signaling by up to 80%, reducing inter-cell interference
Interference
Interference
USER DATA
USER DATA
Figure 3-20: ERICSSON LEAN CARRIER Applying 5G concepts to today’s 4G LTE
Traffic distribution varies geographically and over time and Ericsson Lean Carrier dynamically removes reference signals when they are not needed across the network as traffic load varies over time. Up to 80% reduction in emitted reference signal power reduces severe inter cell interference and enables utilization of higher order modulation – LTE 64 QAM and 256 QAM
2.13
UE Categories The 3GPP have defined 17 LTE UE categories ranging from Category 1 which is a low cost unit supporting a downlink peak bit rate of 10 Mbps up to category 5 which supports a downlink peak bit rate of 300 Mbps using 4X4 MIMO.
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The figure below presents the LTE UE Categories (1/2). Category
0
1
2
3
4
5
6
7
8
DL Peak Rate
1
10
50
100
150
300
300
300
3000
UL Peak Rate
1
5
25
50
50
75
50
100
1500
Max DL mod
64QAM
Max UL mod
Layers for spatial mux.
16QAM
1
1
2
64 QAM
4
16QAM
4(2)
4(2)
64
8
Figure 3-21: LTE UE Categories (1/2)
The peak bit rates shown in the figure above are valid for 20 MHz Channel bandwidth using Frequency Division Duplex (FDD) which means that there is two separate 20 MHz blocks of RF spectrum for downlink and uplink. Since the peak downlink and uplink physical bit rates for 20 MHz bandwidths are 201.6 Mbps and 67.2 Mbps respectively and the Category 4 UE supports a peak downlink bit rate of 150 Mbps and 50 Mbps in the uplink the RS, signaling and coding overhead is approximately 25%.
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LTE/SAE System Overview
The figure below presents the LTE UE Categories (2/2). Category
9
10
11
12
13
14
15
16
17
DL Peak Rate
450
450
600
600
400
400
800
1000
2500
UL Peak Rate
50
100
50
100
150
100
*
*
*
4(2)
4(2)
8
Max DL mod
64 QAM
256 QAM
Max UL mod
16 QAM
64 QAM
Layers for spatial mux.
4(2)
4(2)
4(2)
4(2)
4(2)
8
Figure 3-22: LTE UE Categories (2/2)
There are many other dimensions to a UE category and additional details such as Maximum number of DL-SCH transport block bits received within a TTI or Total number of soft channel bits etc can be found in TS 36.306. As opposed to HSPA in LTE there is only one category for both UL and DL. The category 0 is targeting the M2M market. The figures above including Figure 324: LTE FDD Frequency Bands 2/2 above are relevant for the 17 downlink categories.
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2.14
LTE Frequency Bands The previous bit rate calculations were all based on Frequency Division Duplex (FDD) where there is two separate 20 MHz blocks of RF spectrum for downlink and uplink as illustrated in the figures below. Band
”Identifier”
0
900P
1
IMT Core Band
2
UL [MHz]
5
10
15
20
Duplex
935 - 960
●
●
●
●
45
1920 – 1980
2110 – 2170
●
●
●
●
190
PCS 1900
1850 – 1910
1930 - 1990
●
●
●
●
●
●
80
3
GSM 1800
1710 – 1785
1805 – 1880
●
●
●
●
●
●
95
4
AWS (US & other)
1710 – 1755
2110 - 2155
●
●
●
●
●
●
400
5
850
824 – 849
869 – 894
●
●
●
●
45
6
850 (Japan #1)
830 – 840
875 – 885
●
●
45
7
IMT Extension
2500 – 2570
2620 – 2690
●
●
8
GSM 900
880 – 915
925 – 960
●
●
9
1700 (Japan)
1750 – 1785
1845 -1880
●
10
3G Americas
1710 – 1770
2110 – 2170
11
1500 (Japan #1)
1427.9-1452.9
1475.9-1500.9
12
US 700
698 – 716
728 - 746
●
13
US 700
777 - 787
746 - 756
14
US 700
788 - 798
758 - 768
15,16
Reserved
-
-
890 - 915
DL [MHz]
1.4
3
●
●
●
●
●
95
●
●
●
●
400
●
●
●
●
48
●
●
●
30
●
●
●
●
-31
●
●
●
●
-30
●
●
120 45
Figure 3-23: LTE FDD Frequency Bands 1/2
Band
”Identifier”
UL [MHz]
DL [MHz]
1.4
3
5
10
15
20
Duplex
17
US 700
704 - 716
734 - 746
●
●
18
850 (Japan #2)
815 – 830
860 - 875
●
●
●
45
19
850 (Japan #3)
830 - 845
875 - 890
●
●
●
45
30
20
Digital Dividend
832 – 862
791 - 821
●
●
●
21
1500 (Japan #2)
1447.9 – 1462.9
1495.9 – 1510.9
●
●
●
22
3500
3410 – 3490
3510 – 3590
●
●
●
●
100
23
S-Band (AWS-4)
2000 – 2020
2180 – 2200
●
●
●
●
180
24
L-Band (US)
1626.5 – 1660.5
1525 – 1559
●
●
25
Extended PCS blocks A-G
1850 – 1915
1930 – 1995
●
●
●
●
●
●
80
26
Extended CLR
814 – 849
859 – 894
●
●
●
●
●
27
SMR (adjacent to band 5)
807 – 824
852 – 869
●
●
●
●
28
APT
703 – 748
758 – 803
●
●
●
29
Lower SMH blocks D/E
N/A
717 – 728
●
●
●
●
●
●
●
30
WCS blocks A/B
2305 – 2315
2350 – 2360
31
LTE 450 Brazil
452.5 – 457.5
462.5 – 467.5
32
SDL L-Band
N/A
1452 – 1496
●
●
●
●
●
-41 48
98,5
45 45
●
●
55
45 10
●
●
●
Figure 3-24: LTE FDD Frequency Bands 2/2
In some scenarios LTE is deployed in a frequency band where there is not two separate 20 MHz blocks of RF spectrum for downlink and uplink.
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LTE/SAE System Overview
In these frequency bands illustrated in the figure below, Time Division Duplex (TDD) where the downlink and uplink takes turns to use the same RF spectrum. Band
”Identifier”
Frequencies [MHz]
1.4
3
5
10
15
20 ●
33
TDD 2000
1900 – 1920
●
●
●
34
TDD 2000
2010 – 2025
●
●
●
35
TDD 1900
1850 – 1910
●
●
●
●
●
●
36
TDD 1900
1930 – 1990
●
●
●
●
●
●
37
PCS Center Gap
1910 – 1930
●
●
●
●
38
IMT Extension Center Gap
2570 – 2620
●
●
●
●
39
China TDD
1880 – 1920
●
●
●
●
40
2.3 TDD
2300 – 2400
●
●
●
●
41
US 2600
2496 - 2690
●
●
●
●
42
3500
3400 - 3600
●
●
●
●
43
3700
3600 – 3800
●
●
●
●
44
APT700 LTE
●
●
●
●
●
●
●
698 - 806
45
TD 1500
1447-1467
46
TD Unlicenced
5150-5925
●
● ●
Figure 3-25: LTE TDD Frequency Bands
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2.15
TDD Operation In LTE TDD mode each10 msec Radio Frame is divided into to two equal-sized half-frames consisting of five subframes as illustrated in the figure below.
10 msec Radio Frame
0
1
2
3
DwPTS
GP
UpPTS
5
6
7
DwPTS
GP
UpPTS
4
8
9
TDD Configurations: 0
#0
#2
#3
#4
#5
#7
#8
#9
1
#0
#2
#3
#4
#5
#7
#8
#9
2
#0
#2
#3
#4
#5
#7
#8
#9
3
#0
#2
#3
#4
#5
#6
#7
#8
#9
4
#0
#2
#3
#4
#5
#6
#7
#8
#9
5
#0
#2
#3
#4
#5
#6
#7
#8
#9
6
#0
#2
#3
#4
#5
#7
#8
#9
Figure 3-26: LTE TDD Operation
The second subframe within each half-frame (subframe #1 and #6 within the frame) has a special structure. More specifically, it consists of a downlink part (DwPTS), a guard period (GP), and an uplink part (UpPTS). The downlink-touplink switching point thus takes place within the second subframe of each halfframe, i.e. there can be two downlink-to-uplink switching points within each frame. The corresponding uplink-to-downlink switching point can take place at any sub-sequent subframe boundary within the half-frame. Thus, the first subframe of each half frame is always a downlink subframe. The 3GPP specify seven different TDD configurations with one and two switching points within the 10 msec Radio Frame as illustrated in Figure 3-26: above. The uplink and downlink peak bit rates in the network will depend on the TDD configuration used.
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LTE/SAE System Overview
3
LTE-ADVANCED This standard is a major enhancement of the LTE standard. It was submitted as a candidate 4G system to ITU-T in late 2009 as meeting the requirements of the IMT-Advanced standard. It was standardized by the 3rd Generation Partnership Project (3GPP) in March 2011 as 3GPP Release 10. The main focus is on higher capacity. The markets driving force to further strive towards LTE–Advanced - LTE Release10 was higher bitrates to a low cost, and also, fulfil the requirements set by ITU for IMT Advanced, also referred to as 4G. The main improvements are listed in Figure 3-27 below. LTE Advanced
› Increased peak data rate, DL 3 Gbps, UL 1.5 Gbps › Higher spectral efficiency, from a maximum of 16bps/Hz in R8 to 30 bps/Hz in R10 › Increased number of simultaneously active subscribers › Improved performance at cell edges, e.g. for DL 2x2 MIMO at least 2.40 bps/Hz/cell. LTE-Advanced focus is on higher capacity Figure 3-27: LTE Advanced Rel 10
The main new functionalities introduced in LTE-Advanced are
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•
Carrier Aggregation (CA),
•
Enhanced use of multi-antenna techniques
•
Relay Nodes (RN)
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There is also an improved support for heterogeneous deployments.
Enhancements for Heterogeneous Deployments
Carrier Aggregation Enhancements (New band comb., inter-band TDD w. diff. UL-DL)
(Larger range expansion for co-channel)
CoMP (Co-ordinated Multipoint Transmission) ePDCCH – FDM with data
Downlink Control Channel Enhancements (To enable CoMP and control channel ICIC)
Improved UE requirements (IRC receivers)
Figure 3-28: LTE 3GPP Rel 11 - Further enhancements
One way to increase the peak rate is to use wider bandwidth, up to 100MHz or even more is proposed. This is achieved by aggregating Rel8 carriers, for example by combining 5x20MHz carriers were we get 100MHz in total. This is called carrier aggregation if it is done in the same band and the carriers are contiguous. Spectrum aggregation is used if the carriers are non-contiguous. Non-contiguous also means that the carriers can be in separate spectrum, for example 10 MHZ in 1800 band, 10Mhz in 2600 band etc to get a larger total bandwidth. R8 terminals can still be used in each separate carrier while more advanced terminals are required for the aggregated spectrum. Ericsson uses the term Carrier Aggregation for Inter / Intra and contiguous / non-contiguous bands. Another way to increase peak rates is by using more antennas, up to 8 antennas in downlink and up to 4 in uplink is discussed. 20MHz and 4x4 MIMO gave us peak rate 300Mbps, 5 times that means 1.5Gbps and then if we also double number of antennas, 8 instead of 4, the peak rate in downlink can in theory be as high as 3Gbps. You also remember that peak rate in 20MHz in uplink in Release 8 is 75Mbps as only one data stream is used so 5 times 20MHz gives us 375Mbps and then 4 uplink antennas result in 1.5Gbps! But 3GPP targets for Rel10 are 1Gbps in DL and 500Mbps in UL.
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LTE/SAE System Overview
3GPP Release 11 includes further enhancements of Release 10 solutions as well as new solutions. These enhancements include e.g.: •
Carrier Aggregation enhancements, e.g. new band combinations, interband TDD with different UL/DL bands
•
Enhancements for heterogeneous deployments where larger range expansion for co-channel deployments is enabled
•
Co-ordinated Multipoint Transmission where transmissions in several cells are combined to increase performance. This is to some extent similar to soft handover in WCDMA
•
Downlink Control Channel Enhancements (e.g. Enhanced PDCCH, ePDCCH). Here e.g. The PDCCH is subject to CoMP, Beamforming, ICIC etc to increase coverage and capacity for the DL control signalling.
•
Improved UE requirements increases the performance of the UE receiver, e.g. Reducing inter-cell interference, which otherwise would be a large problem with the other features mentioned here utilized heavily.
3GPP Release 12 includes more enhancements with e.g. FDD/TDD Carrier Aggregation support, 256-QAM and UE receiver enhancements (NAICS).
UL- Carrier Aggregation Enhancements (Support for 2CC Uplink carrier aggregation up to 40MHz) 256-QAM
›
Enhancements for Heterogeneous Deployments (Deployed in single or multicarrier environments)
256-QAM Downlink
8 bits/symbol
Downlink MIMO Enhancements Two Channel State Information (CSI) enhancements
UE Receiver Enhancements Network Assisted Interference Cancellation and Suppression (NAICS) receivers
Figure 3-29: LTE 3GPP Rel 12 - Further enhancements
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For 3GPP Release 13: LTE Advanced Pro 3GPP has approved a new LTE marker see Figure 3-30 that will be used for the appropriate specifications from Release 13 onwards. LTE-Advanced Pro will allow mobile standards users to associate various new features – from the Release’s freeze in March 2016 – with a distinctive marker that evolves the LTE and LTE-Advanced technology series. The new term is intended to mark the point in time where the LTE platform has been dramatically enhanced to address new markets as well as adding functionality to improve efficiency. The major advances achieved with the completion of Release 13 include: MTC enhancements, public safety features – such as D2D and ProSe - small cell dualconnectivity and architecture, carrier aggregation enhancements, interworking with Wi-Fi, licensed assisted access (at 5 GHz), 3D/FD-MIMO, indoor positioning, single cell-point to multi-point and work on latency reduction. Many of these features were started in previous Releases, but will become mature in Release 13.
Enhancements for MTC Enhancements for D2D
Enhancements of LTE-U, LAA
Elevation Beamforming
Fair sharing with Wi-Fi: LBT
FD-MIMO
CA Enhancements
…and more Figure 3-30: Evolution of LTE - 3GPP Release 13
LTE in unlicensed spectrum (aka Licensed-Assisted Access) The goal is to study enhancements for LTE to operate in unlicensed spectrum.
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LTE/SAE System Overview
While licensed spectrum remains 3GPP operators’ top priority to deliver advanced services and user experience, the opportunistic use of unlicensed spectrum is becoming an important complement to meet the growing traffic demand. Licensed-Assisted Access will give operators the option to make use of unlicensed spectrum with a unified network, offering potential operational cost saving, improved spectral efficiency and a better user experience. The focus of the Release 13 work is on the aggregation of a primary cell, operating in licensed spectrum to deliver critical information and guaranteed Quality of Service, with a secondary cell, operating in unlicensed spectrum to opportunistically boost data rate. A key objective of the project is to ensure fair coexistence between LTE LAA and Wi-Fi. Fair sharing with Wi-Fi: To ensure fair sharing of the unlicensed spectrum between LTE and co-existing Wi-Fi, a Listen-Before-Talk algorithm, LBT, can be implemented in the radio to ensure that no other transmission is ongoing before DL transmission burst with PDSCH is transmitted. The LBT functionality can be realized by a CCA (Clear Channel Assessment) algorithm. Carrier Aggregation enhancements The LTE CA framework was standardized in Release 10, with the protocol allowing aggregation of up to 5 Component Carriers (CCs) in downlink and uplink. As operators have planned for deployments with the aggregation of more and more carriers, it has become necessary to expand the LTE CA framework to be able to aggregate more than 5 CCs. The goal in Release 13 is to expand LTE CA up to 32 CCs and hence provide a major leap in the achievable data rates for LTE as well as in the flexibility to aggregate large numbers of carriers in different bands. But the enhanced framework will also be useful for LAA operation in unlicensed spectrum where large blocks of spectrum are available. LTE enhancements for Machine-Type Communications (MTC) Continuing the normative work started in Release 12 to specify key physical layer and RF enablers to enhance LTE’s suitability for the promising IoT market, the key focus for Release 13 is to define a new low complexity UE category type that supports reduced bandwidth, reduced transmit power, reduced support for downlink transmission modes, ultra-long battery life via power consumption reduction techniques and extended coverage operation. In terms of reduced bandwidth the goal is to specify 1.4 MHz operation at the terminal within any LTE system bandwidth, allowing operators to multiplex reduced bandwidth MTC devices and regular devices in their existing LTE deployments. For coverage, the goal is to improve by 15dB the coverage of delay-tolerant MTC devices, allowing operators to reach MTC devices in poor coverage conditions – such as meters located in basements.
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Enhancements for D2D The goal of the project is to enhance the D2D/ProSe framework standardized in Release 12 to support more advanced proximity services for Public Safety (PS) and Consumer use cases. Part of the work will be to support the requirements being identified by the System groups as necessary for Mission Critical Push-ToTalk (MCPTT), which is the ongoing project to complete support of PS services in the 3GPP platform based on the requirements coming from various administrations and industry stakeholders. Elevation Beamforming / Full-Dimension MIMO Beamforming and MIMO have been identified as key technologies to address the future capacity demand. But so far 3GPP evaluations for these features have mostly considered antenna arrays that exploit the azimuth dimension. So 3GPP RAN is now studying how two-dimensional antenna arrays can further improve the LTE spectral efficiency by also exploiting the vertical dimension for beamforming and MIMO operations. Also, while the standard currently supports MIMO systems with up to 8 antenna ports, the new study will look into highorder MIMO systems with up to 64 antenna ports at the eNB, to become more relevant to the use of higher frequencies in the future. Enhanced multi-user transmission techniques The goal of the project is to study downlink multi-user transmissions using superposition coding to see if such techniques can increase spectral efficiency of the LTE system. Indoor positioning The study will first determine the performance of already specified positioning methods in indoor environments, and later evaluate potential improvements to the existing methods or new positioning methods in order to achieve better positioning accuracy. While initially driven by the FCC request to improve the positioning accuracy in indoor environments for emergency calls, the work can further expand the capability of the LTE platform allowing operators to address the growing market of indoor positioning.
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LTE/SAE System Overview
Single-cell Point-to-Multipoint (SC-PTM) eMBMS was developed to efficiently deliver multicast services over areas typically spanning multiple cells. However, there could be a number of applications that may benefit from supporting multicast services over a single cell. A 3GPP Study Item for “Support of single-cell point-to-multipoint transmission in LTE” will determine any potential benefits and solutions of SCPTM operation based on the LTE downlink shared channel.
› Latency reduction
› LAA enhancements
› Enhanced MTC support
› Massive MIMO (enhanced FDMIMO) › ITS/V2x support Figure 3-31: Evolution of LTE Rel14 -3GPP Release 14
5G activities within 3GPP start early 2016 with Release 14. Latency reductions enables improved user performance and new use cases. Licensed Assisted Access enhancements enables increased data rates and higher capacity. Enhanced MTC support enables improved spectral efficiency for massive MTC. Massive MIMO (enhanced FD-MIMO) improves data rates, higher capacity. ITS/V2x support and Intelligent Transport Systems and vehicle to vehicle or vehicle to anything is also addressed. For us 5G wireless access, see figure below, is the overall wireless access solution of the future, fulfilling the needs and requirements for 2020 and beyond. Clearly LTE will be an important part of that future and, consequently, we see the evolution of LTE being a key part of the oveall 5G wireless access solution. More specifically, the evolution of LTE will apply to existing spectrum currently used by LTE, spectrum for which the possibility to introduce 5G capabilities is highly beneficial and, in many cases, vital.
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4
ERICSSON RADIO SYSTEM The Ericsson Radio System is an evolution of RBS 6000 and provides all necessary components for a successful deployment of a heterogeneous network. With the Radio System we are moving from a cabinet based Radio Base Station solution to a modular system that can be adapted to specific operator needs, enabling Multi-band, Multi-standard and Multi-layer sites in distributed, centralized, or any other type of configuration. Cabinet or enclosure is still part of a flexible component in the Radio System just like e.g. the Power or Baseband modules. The key features with Ericsson Radio System hardware are: •
Multi-standard – End to end multi-standard support including radio and baseband
•
Multi-band – The new radios in combination with the innovative rail system provides a very efficient and flexible way to build multi-band sites
•
Multi-layer – Both macro and small cells supported
•
Radio performance – High performance radio and baseband design
•
Scalability – This means having the architecture and building blocks allowing the construction of a site supporting from a single band with Psi Coverage up to several bands
•
Flexibility – Enabling operators to build the sites that they need whether it be a distributed or centralized node, delivering the capacity and performance where it is needed
•
Energy efficiency – Sustainable and profitable networks
•
Total Cost of Ownership – Secure the best business case for mobile networks
The Ericsson Radio System has a modular design, where the different units are used in many different configurations. All hardware and software are backwards compatible with the installed base of RBS 6000 nodes. To allow operators to capitalize on these exciting opportunities, Ericsson has introduced the Ericsson Radio System, an end-to-end radio modular and scalable network portfolio of hardware and software that has been designed to fit all site types and traffic scenarios as networks grow in scale and complexity on the road to 5G.
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LTE/SAE System Overview
Ericsson Radio System is an innovative, modular system that enables mobile operators to address growth opportunities and transform their radio networks by leveraging a multi-standard, multi-band and multi-layer architecture (3xMulti), delivering industry-leading performance on the smallest site footprint with the lowest energy consumption. Ericsson Radio System has been designed to accommodate the mobile data traffic increases expected by 2020 at the same – or lower – energy consumption levels of today. Ericsson Radio System consists of hardware and software for radio, baseband, power, enclosure, antenna and site solutions, the industry-leading MINI-LINK portfolio for microwave transmission and a fully integrated IP Router portfolio, all managed by a common management system. With Ericsson Radio System, operators can reap the benefits of growing mobile broadband demand from consumers, businesses and the Internet of Things (IoT), Cloud RAN to further extend their business as they evolve to 5G. The industry’s most compact radios – 50% smaller and lighter than previous generations – enable more compact, higher density and cost-efficient site designs. Reduction of the Total Cost of Ownership by 20% can be obtained through innovations such as a quick one-bolt installation process combined with the smaller size, weight, wind load and a high energy efficiency. With its fast and flexible deployment capability, site acquisition challenges are solved, time-torevenue is minimized and operating expenses are kept under control. Ericsson Radio System also includes the industry’s most powerful baseband – twice the capacity compared to previous products – enabling operators to build distributed and centralized baseband configurations supporting high-capacity 3xMulti architectures. It is the industries first full Mixed mode baseband supporting GSM, WCDMA, LTE and Massive IoT simultanously on one board. Ericsson’s Many-Core Architecture, at the heart of the new baseband, supports massive multi-core processing with ten times the energy efficiency of commercial, off-the-shelf processors. Multi-standard operation is supported, including carrier aggregation of combined LTE TDD and FDD operation. Going hand in hand with this paradigm shift, is the Ericsson Radio System Software which brings together LTE FDD & TDD, WCDMA and GSM into a unified architecture. With this, operators can better manage the complexities of the network with one O&M system for all standards. Over the past year the Ericsson Radio System has been awarded a number of prestigous prices. It has been the Red Dot Award for both the Ericsson Radio System macro series and Ericsson Radio System micro series. Ericsson Radio System was recognized by the GSMA with the Global Mobile Award for best mobile infrastructure. The flexible architecture of the Ericsson Radio System enables a variety of site deployments and consists of the following building blocks:
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•
Site
•
Radio
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•
Small-cells
•
Front haul
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Baseband and integrated transport
•
Backhaul
•
Power
•
Enclosure including climate system
•
Controller
The figure below presents the Ericsson Radio System building blocks.
Ericsson Radio System Site Types
Radio Nodes
Baseband
Radio
Baseband Interconnect
Macro / Micro
Baseband Processing
AIR
Small Cells
Series
Transport
Fronthaul
Mini-link
Enclosures
Router 6000
Enclosure Module
Power Module
Figure 3-32: From Radio Base Station to Radio System
To allow operators to capitalize on these exciting opportunities, Ericsson has introduced the Ericsson Radio System, an end-to-end radio modular and scalable network portfolio of hardware and software that has been designed to fit all site types and traffic scenarios as networks grow in scale and complexity on the road to 5G. Ericsson Radio System is an innovative, modular system that enables mobile operators to address growth opportunities and transform their radio networks by leveraging a multi-standard, multi-band and multi-layer architecture (3xMulti), delivering industry-leading performance on the smallest site footprint with the lowest energy consumption. Ericsson Radio System has been designed to accommodate the mobile data traffic increases expected by 2020 at the same – or lower – energy consumption levels of today.
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LTE/SAE System Overview
Ericsson Radio System consists of hardware and software for radio, baseband, power, enclosure, antenna and site solutions, the industry-leading MINI-LINK portfolio for microwave transmission and a fully integrated IP Router portfolio, all managed by a common management system. With Ericsson Radio System, operators can reap the benefits of growing mobile broadband demand from consumers, businesses and the Internet of Things (IoT), Cloud RAN to further extend their business as they evolve to 5G. The industry’s most compact radios – 50% smaller and lighter than previous generations – enable more compact, higher density and cost-efficient site designs. Reduction of the Total Cost of Ownership by 20% can be obtained through innovations such as a quick one-bolt installation process combined with the smaller size, weight, wind load and a high energy efficiency. With its fast and flexible deployment capability, site acquisition challenges are solved, time-torevenue is minimized and operating expenses are kept under control. Ericsson Radio System also includes the industry’s most powerful baseband – twice the capacity compared to previous products – enabling operators to build distributed and centralized baseband configurations supporting high-capacity 3xMulti architectures. It is the industries first full Mixed mode baseband supporting GSM, WCDMA, LTE and Massive IoT simultanously on one board. Ericsson’s Many-Core Architecture, at the heart of the new baseband, supports massive multi-core processing with ten times the energy efficiency of commercial, off-the-shelf processors. Multi-standard operation is supported, including carrier aggregation of combined LTE TDD and FDD operation. Going hand in hand with this paradigm shift, is the Ericsson Radio System Software which brings together LTE FDD & TDD, WCDMA and GSM into a unified architecture. With this, operators can better manage the complexities of the network with one O&M system for all standards. Over the past year the Ericsson Radio System has been awarded a number of prestigous prices. It has been the Red Dot Award for both the Ericsson Radio System macro series and Ericsson Radio System micro series. Ericsson Radio System was recognized by the GSMA with the Global Mobile Award for best mobile infrastructure.
4.1
Site Types The Ericsson Radio System Series make it possible to build up different site types by integrating radio, baseband, power, backhaul, fronthaul, battery-backup, enclosures and other site products into groups. Radio System Series support both outdoor and indoor deployments, including zero- footprint and self-contained 19-inch-assemblies.
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The figure below presents the main Outdoor and Indoor solutions of the Ericsson Radio System. › Outdoor: – 61 Series – 63 Series – 65 Series
› Indoor: – 62 Series – 64 Series – 66 Series
Figure 3-33: Ericsson Radio System - Site Types (1/4)
4.1.1
Series The Ericsson Radio System can be evaluated into Outdoor and Indoor Solutions. Outdoor: •
61-series: Floor-mounted macro based site type 61-series enclosure is normally used for radio, baseband, backhaul, fronthaul, power and battery backup.
•
63-series: Zero-footprint macro site type “Carry to site” products for wall or pole mount that reduce site rent and speed up site acquisition
•
65-series: Self-contained micro site type Micro product with baseband, radio and backhaul supporting single as well as multi sector.
Indoor:
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62-series: Enclosure-based site type Enclosure-based floor mounted, zero-footprint or larger 19” shelf based products.
•
64-series: Self-contained Pico site type Pico radio with integrated baseband and backhaul.
•
66-series: Self-contained 19” products site type Self-contained products optimized for installation in standard 19’’ racks.
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LTE/SAE System Overview
The figure below presents the main Outdoor and Indoor solutions of the Ericsson Radio System.
Figure 3-34: Ericsson Radio System - Site Types (2/4)
The figure below presents the Radio System Series subdivided into Radios, Basebands, Backhaul, Fronthaul and Radio Sites.
Figure 3-35: Ericsson Radio System - Site Types (3/4)
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The figure below presents more examples of Radio System Series.
Figure 3-36: Ericsson Radio System - Site Types (4/4)
4.1.1.1
RBS 6101 RBS 6101 is the small outdoor base station belonging to the highly successful RBS 6000 family of state-of-the-art, multi standard base stations. The RBS 6000 series is designed to support a flexible mix of GSM, WCDMA, LTE and CDMA in the same base station, thereby ensuring a smooth transition between the radio technologies. RBS 6101 provides world-leading performance when it comes to radio performance, capacity capabilities and flexibility. RBS 6101 can be used in a wide range of different applications. All equipment needed for constituting a complete site, such as power supplies and transmission equipment, is integrated in the single cabinet. Battery backup can be supplied either internally or externally. RBS 6101 can be configured as a complete macro site with internally installed radio units. Used as a macro site, RBS 6101 can be equipped to provide virtually any combination of digital and radio units, available for all relevant radio standards and frequency bands. RBS 6101 can also be used as a main unit in a main-remote configuration. Here, the radios are remotely installed in order to provide the best radio link budget possible. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR) where the radio parts and the antenna are integrated in one single unit. The remote radios are connected with optical fiber CPRI links. RBS 6101 also provides power supply to up to nine remote radios. The two types of configurations, macro and main-remote, can be combined in the RBS 6101 cabinet. In these hybrid configurations, RBS 6101 is equipped both with internal radio units as well as connected to remote radios
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4.1.1.2
RBS 6102 RBS 6102 is the high capacity outdoor base station belonging to the highly successful RBS 6000 family of state-of-the-art, multi standard base stations. The RBS 6000 series is designed to support a flexible mix of GSM, WCDMA, LTE and CDMA in the same base station, thereby ensuring a smooth transition between the radio technologies. RBS 6102 provides world-leading performance when it comes to radio performance, capacity capabilities and flexibility. RBS 6102 can be used in a wide range of different applications. All equipment needed for constituting a complete site, such as power supplies and transmission equipment, is integrated in the single cabinet. Battery backup can be supplied either internally or externally. RBS 6102 can be configured as a complete macro site with two shelves of internally installed radio units. Used as a macro site, RBS 6102 can be equipped to provide virtually any combination of digital and radio units, available for all relevant radio standards and frequency bands. RBS 6102 can also be used as a main unit in a main-remote configuration. Here, the radios are remotely installed in order to provide the best radio link budget possible. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR) where the radio parts and the antenna are integrated in one single unit. The remote radios are connected with optical fiber CPRI links. RBS 6102 also provides power supply to up to eighteen remote radios. The two types of configurations, macro and main-remote, can be combined in the RBS 6102 cabinet. In these hybrid configurations, RBS 6102 is equipped both with internal radio units as well as connected to remote radios.
4.1.1.3
RBS 6120 The RBS 6120 is a multi flexible outdoor radio base station that belongs to the new generation outdoor enclosure system. The RBS is designed to support a flexible mix of GSM, WCDMA and LTE in one cabinet thereby ensuring smooth transition between radio standards. The RBS 6120 provides world leading performance in radio performance, capacity and capability. The RBS 6120 is designed to support any hybrid, macro or main remote configuration. This allows for flexible site configurations when it comes to deployment of digital and radio units. The deployment can be realized in one or several cabinets allowing for internal or external location of transmission equipment or batteries. The RBS 6120 can be ordered as an AC powered site, holding its own rectifiers, with internal or external batteries. RBS 6120 can also be ordered as a DC powered site with optional external power outputs for customer equipment. Any choice of direct air cooling (DAC) or Thermosiphone cooling system is available from start.
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Used as a macro site the RBS 6120 can be configured to provide Remote Radio RBS 6120 AC any combination with up to 8 digital and up to 12 radio units for all relevant radiostandards and frequency bands. The RBS 6120 can also be used as a main unit in a main remote configuration using up to 16 internally installed digital units and up to 18 remote radio units. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR).
4.1.1.4
RBS 6201 RBS 6201 is the high capacity indoor base station belonging to the highly successful RBS 6000 family of state-of-the-art, multi standard base stations. The RBS 6000 series is designed to support a flexible mix of GSM, WCDMA, LTE and CDMA in the same base station, thereby ensuring a smooth transition between the radio technologies. RBS 6201 provides world-leading performance when it comes to radio performance, capacity capabilities and flexibility. RBS 6201 can be used in a wide range of different indoor sites. All equipment needed for constituting a complete site, such as power supplies and transmission equipment, can be integrated in the single cabinet. Battery backup can be supplied externally. RBS 6201 can be configured as a complete macro site with two shelves of internally installed radio units. Used as a macro site, RBS 6201 can be equipped to provide virtually any combination of digital and radio units, available for all relevant radio standards and frequency bands. RBS 6201 can also be configured as a hybrid base station, with both internal radio units and main unit equipment for connection of remotely installed radios, in order to provide the best radio link budget possible. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR) where the radio parts and the antenna are integrated in one single unit. The remote radios are connected with optical fiber CPRI links. RBS 6202 RBS 6202 is the compact (zero footprint) indoor base station belonging to the highly successful RBS 6000 family of state-of-the-art, multi standard base stations. The RBS 6000 series is designed to support a flexible mix of GSM, WCDMA, LTE and CDMA in the same base station, thereby ensuring a smooth transition between the radio technologies. RBS 6202 provides a multi standard base station in any 19 inch rack solution, offering world-leading performance when it comes to radio performance, capacity capabilities and flexibility. RBS 6202 can be used in a wide range of different indoor sites where site space is an issue. Battery backup can be supplied externally.
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LTE/SAE System Overview
RBS 6202 can be configured as a complete macro site with one shelf of internally installed radio units. Used as a macro site, RBS 6202 can be equipped to provide virtually any combination of digital and radio units, available for all relevant radio standards and frequency bands. RBS 6202 can also be used as a main unit in a main-remote configuration. Here, the radios are remotely installed in order to provide the best radio link budget possible. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR) where the radio parts and the antenna are integrated in one single unit. The remote radios are connected with optical fiber CPRI links. The two types of configurations, macro and main-remote, can be combined in the RBS 6202 cabinet. In these hybrid configurations, RBS 6202 is equipped both with internal radio units as well as connected to remote radios.
4.1.1.5
RBS 6301 RBS 6301 is the outdoor “carry-to-site” main-remote base station belonging to the highly successful RBS 6000 family of state-of-the-art, multi-standard base stations. The RBS 6000 series is designed to support a flexible mix of GSM, WCDMA, LTE and CDMA in the same base station, thereby ensuring a smooth transition between the radio technologies. RBS 6301 focuses on delivering high radio performance in a complete site. It is made for easy “carry-to-site” installations. The compact size and low weight simplifies passages through doors, tight corridors, staircases, elevators, manholes etc. The radios are remotely installed in order to provide the best radio link budget possible. The remote radios can be of two types: remote radio units (RRU) installed close to the antenna, or antenna integrated radio units (AIR) where the radio parts and the antenna are integrated in one single unit. The remote radios are connected with optical fiber CPRI links. An optional battery backup equipment, BBS 6301, can be connected to the base station. The backup system shares the basic hardware design with RBS 6301.
4.1.1.6
RBS 6302 RBS 6302 is an outdoor main-remote base station, ideal for deployment in challenging environments. The main-remote concept reduces feeder losses and enables the system to use the same high-performance network features at lower output power, thereby lowering power consumption and both capital and operational expenditure. The convection cooling technique guarantees silent operation and removes the need for scheduled maintenance. This makes RBS 6302 the ideal choice where low acoustic noise levels are of major importance.
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The radio units connected to the RBS 6302 main unit can be either remote radio units (RRU), designed to allow easy deployment, preferably close to the antennas for pole, wall or tower installation, thereby minimizing feeder losses. The other alternative is to use antenna-integrated radio units (AIR), where the radio unit and the antenna are combined into a single unit and installed in the usual antenna location.
4.1.1.7
RBS 6402 The RBS 6402 is a high performance indoor Pico Cell offering three standards (LTE, WCDMA and Wi-Fi), 10 frequency bands and up to 300 Mbps LTE carrier aggregation. The flexibility, cost-effectiveness and performance in a tablet-sized footprint make it optimal for smaller buildings.
4.1.1.8
RBS 6501 Ericsson multi-standard micro RBS 6501 supporting 3GPP 37.104 which gives full medium range coverage support in a heterogeneous network environment. The integrated radio with 2x5 W provides right micro cell size & capacity. The RBS 6501 is designed to handle high capacity micro cells, single or multi sectors. RBS 6501 also supports multiband sites with an integrated interface to micro RRU. The multi-standard design allows for migration from WCDMA to LTE with help of a SW upgrade. The compact design and high integration makes it easy to find suitable site locations for optimal radio performance. The deployment and commissioning process is made easy with auto integration. All this coupled with Macro feature parity for WCDM, LTE, including e.g. MIMO and carrier aggregation makes the RBS 6501 the easy choice for operators looking at deploying outdoor small cells in heterogeneous networks
4.1.1.9
RBS 6601 RBS 6601 is a main-remote solution optimized to deliver high radio performance for efficient cell planning in a wide range of indoor applications. The main-remote concept provides the same high-performance network capabilities as macro base stations, but with lower power consumption and less site requirements. The radio units connected to the RBS 6601 main unit can be either remote radio units (RRU), designed to allow easy deployment, preferably close to the antennas for pole, wall or tower installation, thereby minimizing feeder losses. The other alternative is to use antenna-integrated radio units (AIR), where the radio unit and the antenna are combined into a single unit and installed in the usual antenna location.
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The figure below presents the RBS 6601.
› 19 inch indoor main unit for baseband › Mix and match – – – – –
Baseband 5212 Baseband 5216 Baseband R503 Baseband T503 RBS 6000 DUG, DUS & TCU
› Provide the optimal capacity & configuration of GSM, WCDMA or LTE and combinations thereof
Figure 3-37: Ericsson Radio System - RBS 6601
4.2
Radio Nodes In the Ericsson Radio System the Radio Nodes are divided into Radio Modules, Baseband Modules and Small Cells. Small cells
RBS 6402
RD 2242
RD 4442
IRU 2242
IDU 5205
IDU 5209
Radio Modules
Radio 0208
Radio 2217
Radio 2218
Radio 8808
Radio 2219
Radio 4407
Radio 2203
AIR 11, AIR 21, AIR 32, AIR 2488
Baseband Modules
Baseband 5212
Baseband 5216
Baseband R503
Baseband C608
Baseband P614
Baseband 6630/6620
Baseband 6502
Baseband 6303
Figure 3-38: Ericsson Radio System - Radio Nodes
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4.2.1
Radio Modules There are different versions of radios that support macro or micro configurations.
4.2.1.1
Radio Macro Below can be find a list of Radio Macro possibilities.
4.2.1.1.1
•
Radio 2217
•
Radio 0208
•
Radio 2212
•
Radio 2012
•
Radio 4415
•
Radio 2219
•
Radio 2216
•
Radio 2218
•
Radio 4407
•
Radio 4412
•
Radio 8808
AIR – ANTENNA INTEGRATED RADIO Ericsson Antenna Integrated Radio (AIR) addresses the challenge of rolling out high quality HSPA and LTE coverage rapidly and cost effectively by integrating both antennas and radio units in a single, easy-to-install assembly. In this way, AIR simplifies and speeds up the process of building network coverage and capacity with no need for additional antennas and Remote Radio Units (RRUs). The AIR unit replaces the antenna, RRUs, Tower Mounted Amplifiers (TMA), feeders and jumpers. An AIR unit can also cater for regular passive antenna functionality on several different frequency bands while at the same time serve as antenna integrated radio unit for up to two different active bands.
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Fewer boxes need to be installed per site:
•
Reducing site cost
•
Easier to find new sites/upgrade existing sites (zoning and jurisdictional approvals)
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LTE/SAE System Overview
Installed in a mast it reduces the overall wind loading compared to traditional configurations The tight radio and antenna integration in AIR improves the radio performance as well as overall link budget and indoor coverage. AIR is a multi-standard unit supporting single or mixed mode operation of GSM, WCDMA and LTE for applicable frequency bands.
› AIR: Antenna Integrated Radio › Specialized to improve and densify challenging macro sites
AIR 11
AIR 21
AIR 21
AIR 2488
AIR 32
Figure 3-39: Ericsson Radio System – AIR
The current AIR family consist of the four family members AIR 11, 21, 2488 (New) and 32 with different characteristics all bringing benefits for an operator. AIR’s functionality is straight forward. Ericsson has combined three functions into one: 1. a dual TX remote radio unit, RRU 2. an antenna for the RRU, and 3. another passive antenna for yet another frequency band This is done within an outline that is very similar to a regular antenna with the same radiation pattern that you get from AIR. A site solution with AIR is much cleaner than an antenna/RRU solution. There are only three basic types of interfaces: 1. Optical fibers for CPRI that connects to a base-band just like an RRU. 2. Power for the active frequency band’s radios. -48 V DC, again just like for RRUs. 3. An optional regular 7/16 RF connectors for an additional passive antenna functionality.
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AIR 11: 2tx 2rx, 1.3m and 2m •
Active single low band, X-pol antenna column
•
Passive single low band (2 ports)
AIR 21: 2tx 4rx, 1.3m, 2m and 2.4m •
Active on single high band on dual X-pol antenna column
•
Passive on single high(2 ports) OR dual high(2 ports) OR single low(2 ports) band
•
Enabling 4-antenna receiver technology implemented as user specific uplink beamforming using 4-way RX diversity (MRC) and Interference Rejection(IRC)
•
….further improved UL budget and performance compared to AIR 11
AIR 2488: 1,4 m with field replaceable radios for easy upgrade or pay as you grow business model •
Dual or single active band, 2TX - 4RX, GSM, WCDMA and LTE
•
Dual HB x-pol column array
•
Up to 2 x 60W internal PA
•
IBW: 60/70 MHz LTE, WCDMA; 20 MHz GSM
•
Carrier capacity: 8 GSM; 8 WCDMA; 6 LTE
•
Up to 10 Gbps CPRI
•
Passive band: Up to 4xHB and 4x2600 MHz passive ports
•
1.4m antenna gain length class
•
Passive cooling
AIR 32: 4TX 4RX, currently available in roadmap as 1.3m and 2m variants*.
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•
Active single or dual high band, dual X-pol antenna column
•
Passive single high(4 ports) OR dual high(2 ports) AND/OR single low(2 ports) band
•
Enabling 4-antenna receiver & transmitter technology implemented as:
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user specific UL beamforming using 4-way RX diversity (MRC) and Interference Rejection(IRC) user specific DL beam forming using closed-loop spatial multiplexing (MIMO), LTE TM4, DL transmission, i.e. adding beamforming on top of dual layer transmission ,i.e. 2x2 DL spatial multiplexing (MIMO)
4.2.1.2
Radio Micro Below can be find a list of Radio Micro possibilities.
4.2.2
•
Radio 2217
•
Radio 2203
Smal Cells Ericsson ambition is to create a wireless environment where the indoor and outdoor networks perform perfectly and seamlessly together everywhere at anytime to enable the best end user experience. This is made possible through a holistic view of the network and securing performance across all radio network layers (macro and small cells) for multiple bands and standards. Such experience is achieved when all radio network layers work as one logical network, including performance monitoring, providing continued capacity and performance regardless of where users are: indoor, outdoor or on the move. To meet the high requirements of network subscribers and to tackle the challenges of urbanizing environments, we need to take a new approach to network performance. Small Cells alone improve the network performance in certain areas, but integrated Small Cells (macro and small cells combined) deliver high per-user capacity and rate coverage everywhere, with the potential to improve performance in the macro network by offloading traffic generated in hotspots. There are different solutions used to implement a Small Cell site:
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•
Pico RBS
•
Micro RBS
•
Radio Dot System
•
Wifi Spots
•
mRadio
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4.2.2.1
Pico RBS – RBS 6402 The RBS 6402 is a high performance indoor Pico Cell offering three standards (LTE, WCDMA and Wi-Fi), 10 frequency bands and up to 300 Mbps LTE carrier aggregation. The flexibility, cost-effectiveness and performance in a tablet-sized footprint make it optimal for smaller buildings.
Performance › 300 Mbps LTE Carrier aggregation › 2 LTE Carriers 5,10 ,15 or 20 MHz Dual band › 4x250 mW output power › 21 Mbps HSPA (HW prep 42 Mbps)
Flexibility › Up to 10 bands in one unit › Remote selection of Band › 3 Standards, LTE, WCDMA and Wi-Fi simultaneous operation
Easy to deploy › Small All-in-One solution › Data & Power over Ethernet and SON features. › Network-live in 10 min.
Figure 3-40: Ericsson Radio System - RBS 6402
4.2.2.2
Micro RBS – RBS 6502 Ericsson multi-standard micro RBS 6501 supporting 3GPP 37.104 which gives full medium range coverage support in a heterogeneous network environment. The integrated radio with 2x5 W provides right micro cell size & capacity. The RBS 6501 is designed to handle high capacity micro cells, single or multi sectors. RBS 6501 also supports multiband sites with an integrated interface to micro RRU. The multi-standard design allows for migration from WCDMA to LTE with help of a SW upgrade. The compact design and high integration makes it easy to find suitable site locations for optimal radio performance. The deployment and commissioning process is made easy with auto integration. All this coupled with Macro feature parity for WCDM, LTE, including e.g. MIMO and carrier aggregation makes the RBS 6501 the easy choice for operators looking at deploying outdoor small cells in heterogeneous networks.
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The figure below presents the micro RBS 6501. › High capacity
› Output power matters –2x5 W in order to build a strong micro cell
– 1000 connected LTE users
› RBS 6501 supports CPRI out –Dual band and Multi sector flexibility. –6 Cell carriers, 168/23 Mbit/s (DL/UL) –LTE: 120 MHz, 225/75 Mbit/s (DL/UL)
› Easy and Flexible Deployment – AC or DC Power Supply – Integrated GPS with antenna – Integrated or External Antenna
Figure 3-41: Ericsson Radio System - RBS 6501
4.2.2.3
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Micro Radio 2203 •
2TX/2RX FDD, 4TX/4RX by use of two 2203
•
2x5W
•
40 MHz IBW (B1, B2, B3 & B66A: 45 MHz)
•
Up to 4 carriers WCDMA
•
Up to 40 MHz LTE carriers
•
2x 2.5/4.9/9.8 Gbps CPRI
•
4 liter, less than 5kg incl bracket and cover
•
AC or -48 VDC
•
Integrated or external antenna
•
2 external alarm
•
IP 65
•
-40 to +55 ̊C
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4.2.2.4
4.2.2.5
Micro Radio 2205 •
2TX/2RX
•
2x500mW
•
60 MHz IBW TDD
•
Up to 3 LTE carriers
•
2x 2.5/5/9.8Gbps CPRI
•
4 liter, less than 5kg incl bracket and cover
•
AC or -48 VDC
•
Integrated or external antenna
•
2 external alarm
•
IP 65
•
-40 to +55 ̊C
•
Operating Band
•
B46 (LAA)
Wifi Spots Ericsson continues to support our customer’s Wi-Fi requirements and strategies through a variety of offerings, including:
4.2.2.6
•
Strategic partnerships to deliver world-class Wi-Fi solutions for both indoor and outdoor carrier and enterprise applications
•
Robust Wi-Fi software solutions that deliver superior wireless connectivity and network manageability to cable and other operators
•
Broad range of Ericsson-designed software features and platforms that ensure seamless connectivity and best end-user experience
RD – Radio Dot System The Ericsson Radio Dot System is a breakthrough solution that eliminates all barriers to indoor mobile coverage and capacity, to effectively connect indoor users to the whole mobile eco-system. This positions Operators to grow and protect their current indoor business, while also enabling them to expand their opportunities in the Enterprise market.
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LTE/SAE System Overview
The solution is based on a set of innovations making it possible to provide indoor Mobile Broadband across remotely powered active antenna elements using standard enterprise LAN cabling, while sharing common baseband and radio resources. With the Radio Dot System, Ericsson has redefined the indoor small cells concept with the industry’s most cost-effective, most modular and highest performing indoor system. This will allow operators to address and target a wide range of building environments with a common solution. Unlike traditional RBSs, the connection of the radio towards the antenna is to use a CAT 6/7 twisted pair cable. The RDS consists of the following three main subsystems: • Digital Unit (DU) or Baseband •
IRU
•
RD
›Description – The innovative Ericsson Radio Dot System features an elegant design, both in the product and the network architecture, enabling a simple deployment that offers 100% radio coordination across both the outdoor and indoor network domains – Enhanced in L17.Q1 › New Dual Band Radio Dot is introduced › RDS with Baseband 5212 and 5216 is enhanced with Mixed mode radio and mixed mode baseband support › IDU5205 and IDU5209 are enhanced with mixed mode support. › New Remote Indoor Radio Unit (IRU) is introduced
›Operator benefit – Enables mobile operators to deliver consistently high performance voice and data coverage and capacity in the broadest range of enterprise buildings and public venues, including the underserved, high growth, medium-to-large building and venue category.
Figure 3-42: Ericsson Radio System - Radio Dot (1/2)
The DU or Baseband processes baseband signals and provides digital transceiver functionality to the IRU through a CPRI cable, as shown in the figure above. The IRU is an intermediate transceiver and a converter between the DU or Baseband digital radio signals and the RD radio signals. The RD is connected to the IRU over the RDI. The RD transmits and receives radio waves for indoor broadband coverage.
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The figure below presents the Radio Dot System Improvements based in the release L17A. Radio Dot
CAT 6 or 7 twisted pair
Indoor Radio Unit
CPRI
Digital Unit
(20 to 200 m)
Up to 12 IRUs and 18 cells using the Baseband 5216 IRU2242 is supported in - 8 RDs (1 cell & 1 frequency) L17A. Standard Baseband
RD2242 - Single Frequency band - 40 MHz IBW - 2x2 MIMO (17 + 17 dBm) - TX/RX Diversity - 2x1 MISO (1x 20 dBm)
- Baseband 5212 or 5216 - DUS 31 or 41
IDU5205 New in L17A RD4442
- 24 RDs - 600 Mbps New in L17A - Mixed Mode LTE & WCDMA
- Dual Band (LTE + WCDMA) - 2 X 40 MHz IBW - 2x2 MIMO (17 + 17 dBm) - TX/RX Diversity - 2x1 MISO (1x 20 dBm)
IDU5209 Remote IRU New in L17A - 8 or 16 RDs configuration - Integrated AC power supply
- 48 RDs New in L17A - 1 Gbps - Mixed Mode LTE & WCDMA
Figure 3-43: Ericsson Radio System - Radio Dot (2/2)
4.2.3
Baseband Modules Ericsson took the world’s best baseband and made it better. Customer experience in live networks around the world demonstrates Ericsson technology leadership with the best performing networks and the industry’s most compact baseband. Multi-core - Ericsson has taken its world leading Many-Core Architecture and doubled the number of processor cores and coupled it to cutting-edge parallel processing software to deliver the industry-leading radio network system. Ericsson’s Many-core baseband Architecture supports massive multi-core processing with 10 times the energy efficiency of commercial, off-the-shelf processors. Multi-standard - Ericsson’s baseband unit supports LTE (FDD & TDD), WCDMA and GSM on the same, single-board, hardware platform. This provides operators with a future-proof solution and full flexibility in terms of how and when to migrate existing spectrum assets to LTE. Full Mixed-mode – It can run GSM, WCDMA, LTE and Massive IoT concurrently on a single Baseband board. With the increased capacity of Ericsson’s latest Baseband the amount of space and energy required can be reduced. Ericsson’s Baseband architecture provides operators with easy migration of GSM or WCDMA spectrum to LTE, with a simple software update. It is designed for 5G compatibility. It supports Ericsson 5G Plug-Ins which are software-driven innovations that bring key 5G technology concepts to today's mobile network.
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Cell capacity - Supporting 5 LTE bands with Carrier Aggregation or aggregating FDD & TDD carriers to provide coverage AND capacity, Ericsson’s baseband unit provides the bandwidth required to meet the needs or increasing traffic and customers’ performance expectations. The Baseband function in the Ericsson Radio System consists of a number of different products that are used to perform the following important tasks in a radio network: •
Multi-standard GSM, WCDMA and LTE (FDD/TDD)
•
Baseband processing for the uplink and downlink
•
The interfaces between the radio network and the O&M interface for the node
•
Synchronization from the transport network connection or external GPS
•
Backhaul connectivity
•
Passive Inter Modulation (PIM) mitigation
•
Baseband interconnect for elastic RAN
Baseband:
Baseband 5212
Baseband Radio Interconnect:
Baseband R503
Baseband 5216
Baseband Main Unit Figure 3-44: Ericsson Radio System - Baseband Portfolio
Operators will need to manage a complex mix of radio standards, bands and layers over time, and Ericsson is pacing such emphasis on the successful delivery of a 3xMulti radio network evolution with best performance, robust mobility and maximum spectrum efficiency. Operators typically already have multiple radio technology standards in operation (most commonly GSM, WCDMA-HSPA and LTE). Even as new standards are introduced, all these standards are likely to continue to coexist for many years to come.
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With multi-standard mixed mode solution, operators will be able to spread their capital and operating costs across all generations of radio technology and shift traffic handling capacity to the technology that needs it. Hardware- and energyefficiency will be greatly enhanced. As operators roll out 4G LTE networks, and begin developing their strategies for introducing 5G technology, many are keen to refarm spectrum currently used for 2G and 3G networks to the newer, more efficient mobile broadband technologies as soon as possible. Thin Layer GSM is a solution to enable an efficient, highperformance and future-ready GSM network that enables operators to refarm much of their 2G spectrum to 3G and 4G to meet the growing demand for mobile broadband. Such a ‘Thin Layer’ GSM network will be able to handle remaining 2G voice traffic and M2M traffic within much smaller spectrum demands and remain in operators’ networks for a long time. With multiple radio bands in service in their networks, it will be vital for operators to maximize the spectrum efficiency and utilization of these bands. With features like Carrier Aggregation for LTE and Dual Band Multi-Carrier for HSPA, the network is able to deliver higher throughput, capacity, coverage and therefore enhanced user experience from existing frequency allocations. Carrier Aggregation for LTE can combine both FDD and TDD frequencies as well as licensed and unlicensed frequencies. Dual Band Multi Carrier for HSPA enables band combination of low band and high band for extended coverage reach and improved spectrum efficiency.
BASEBAND C608
RADIO
BASEBAND 6303
BASEBAND P614
BASEBAND 6502
BASEBAND 6620 POWER 6302 BASEBAND 6630
Figure 3-45: Ericsson Radio System - Enhanced Baseband Portfolio
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4.2.3.1
Baseband 5212 Baseband 5212 provides the baseband processing resources for the encoding and decoding of the uplink and downlink radio signals, the radio control processing, the radio network synchronization, the IP interface and the O&M interface for the Ericsson Radio System. Baseband 5212 brings together LTE FDD & TDD, WCDMA and GSM onto the same hardware and software architecture, providing operators with unparalleled flexibility and scalability. Baseband 5212 is the standard capacity baseband unit, designed to address high capacity sites and provide flexibility by adding baseband units according to the operators capacity needs.
4.2.3.2
Baseband 5216 Baseband 5216 is part of the Ericsson Radio System and provides the baseband processing resources for the encoding and decoding of the uplink and downlink radio signals, the radio control processing, the radio network synchronization, the IP interface and the O&M interface for the Ericsson Radio System. Baseband 5216 brings together LTE FDD & TDD, WCDMA and GSM onto the same hardware and software architecture, providing operators with unparalleled flexibility and scalability. Baseband 5216 is the premium capacity baseband unit, designed to address extreme capacity sites and provide flexibility with simultaneous operation of two standards on one baseband unit.
4.2.3.3
Baseband R503 Baseband R503 is part of the Ericsson Radio System and increases connectivity for new & existing radio units in large radio system configurations. Legacy RRUs and Digital Units support CPRI interfaces upto 2.5 Gbps. New Baseband and Radios support CPRI interfaces upto 10 Gbps. It is a platform for CPRI rearrangement for instance multiplexing / demultiplexing as well as media conversion electrical optical.
4.2.3.4
Baseband C608 Baseband C608 is an integral part of the Ericsson Radio System and acts as a baseband interconnect for Elastic RAN. With our Elastic RAN solution it possible to build a borderless network where all baseband are interconnected to maximize efficiency and end-user experience.
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To connect more than three basebands using the interconnect links a very low latency layer 2 switch is required, to achieve the maximum coordination. The Baseband C608 is a powerful switch that is used to interconnect the distributed and centralized Basebands in the network. It supports 12x 10 Gbps ports. 1x 10 Gbps port is required per baseband for Carrier Aggregation. Future expansion is possible by adding another Baseband C608 to support UL-CoMP.
4.2.3.5
Baseband P614 Baseband P614 mitigates passive inter modulation (PIM) and operates in the digital domain by analyzing the downlink and uplink digital streams on the CPRI links between the baseband and radio. It uses intelligent algorithms to mitigate the PIM disturbances in the uplink signal before it is decoded in the baseband unit. It can mitigate PIM, both created inside or outside the antenna system from static and dynamic PIM sources and also different band combinations. By doing so it: •
Improves network performance
•
Reduce trouble-shooting effort
•
Enables new band activation on challenging sites
It is a 19-inch unit with 1 HU in height and is end-to-end integrated in Ericsson Radio System and its management system.
4.2.3.6
Baseband 6620/6630 Baseband 6620/6630 are part of the Ericsson Radio System and has a 19-inch, 1 HU building practice. It has the same capacity and mixed mode capabilities as the Baseband 5212/5216. Baseband 6620/6630 is stand-alone and has its own climate control. It also has support for 15 CPRI ports. Baseband 6620/6630 is typically recommended for new installations where a 19inch building practice is used. Baseband 6620/6630 equals 19 inch Baseband Main Unit + Baseband 5212/5216 + Baseband R503
4.2.3.7
Baseband 6502 Baseband 6502 is a multi-standard baseband unit that is optimized for micro sites and works seamlessly with Ericsson Radio System micro radios (Radio 2203/2205). It can be integrated with the Radio 2203/2205, used on the Ericsson Rail or used on sites with distributed radios and baseband architectures.
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It is visually attractive, less than 5 liters in size. It can be AC or DC powered and it supports power-over Ethernet for the MINI-LINK all-outdoor unit enabling highly integrated all outdoor micro site solutions. As it is an integral part of Ericsson Radio System there is full coordination with the macro cells.
4.2.3.8
Baseband 6303 Baseband 6303 enables operators to densify their macro network where available site space is an issue. It enables the operator to build ‘true’ zero footprint Macro sites. It is a multi-standard powerful outdoor baseband unit with similar capacity as the Baseband 5212 that can be installed on the Ericsson Rail system with onebolt installation. It is visually attractive, less than 5 liters in size. It can be AC or DC powered and it supports power-over Ethernet for the MINI-LINK all-outdoor unit. Together with the rail-mounted Power 6302 solution, this allows operators to build sites without enclosure; quickly and compact.
4.3
Transport The Ericsson Radio System offers many possibilities to improve the Transport Solution: •
Transport Fronthaul
•
Transport Backhaul
ROUTER 6000
Indoor
Router 6672
MINI-LINK
Outdoor
Indoor
MINI-LINK 6691
Switch 6391
PT 2020 RAU2 X MINI-LINK 6352
FRONTHAUL
Fronthaul 6681
MINI-LINK 6363
Outdoor
Indoor
Fronthaul 6682
Fronthaul 6689
Fronthaul 6688
MINI-LINK 6351
Fronthaul 6385
Fronthaul 6388
Fronthaul 6392
Figure 3-46: Ericsson Radio System – Transport
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4.3.1
Ericsson Backhaul The expected growth in mobile broadband will have a massive impact on the backhaul network capacity and support for various flavors of radio access network. Concurrently, the long-established trend in backhaul networks for wireless media to replace copper will continue, as copper does not have adequate scalability to meet future demands. In addition, fiber will replace copper and wireless media where and when additional costs and deployment complexity can be justified. A combination of microwave and fiber based backhaul is needed for mobile networks on the road to 5G. Ericsson offers the right solution to achieve this combination: MINI-LINK and Router 6000. These products are fully integrated into the Ericsson Radio System and managed, end-to-end, by Ericsson Network Manager. The latest MINI-LINK solution offers a highly compact and cost-efficient microwave node, as it has a 70% less footprint compared to today’s solution. It also offers market leading node and link capacities in all frequency bands (including the new V- and E-bands). With the world´s smallest high power radio unit, outdoor terminal size can be minimized. A new compact indoor unit and a new dual carrier all outdoor unit, for traditional frequency bands, are added to the portfolio. The Multi-band booster concept is also introduced to combine the best characteristics of different frequency bands to boost capacities, hop lengths and improved spectrum usage •
Aggregation Units o
•
•
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Switch 6391
MINI-LINK Indoor Units o
MINI-LINK TN R6
o
MINI-LINK LH R2
o
MINI-LINK 6600 R1
o
MINI-LINK CN 510 R2
o
MINI-LINK LH R1
o
MINI-LINK TN R5 ETSI
o
MINI-LINK TN R5 ANSI
MINI-LINK Outdoor Units o
MINI-LINK 6366 R1 (NEW)
o
MINI-LINK 6351
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•
4.3.2
o
MINI-LINK 6352
o
MINI-LINK 6363
o
MINI-LINK PT 2020
o
MINI-LINK Outdoor RAU
o
Switch 6391
Router 6000 Series o
Router 6675
o
Router 6672
o
Router 6471
o
Router 6371
•
Site Transmission
•
RAN Transmission
•
CCS
•
RADWIN
Ericsson Fronthaul The increasing demand for mobile broadband capacity and the high value of radio spectrum has resulted in radio features requiring innovative configurations. One such configuration is the colocation of baseband units in a Centralized RAN (C-RAN) architecture. This has facilitated the use of Coordinated Multipoint (CoMP) for expanding and optimizing radio coverage. As a result, the link between remote radio units and baseband units is no longer a simple one-to-one relationship due to the increase in distance and the subsequent transmission latency which impacts radio performance.
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•
Fronthaul 6392
•
Fronthaul 6080 DWDM passive
•
Fronthaul CWDM CWDM passive
•
Fronthaul 6080 DWDM active
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The figure below summarizing the backhaul and fronthaul operation.
› One system
Fiber, Copper or Microwave backhaul
– Microwave
Baseband
– IP Routing
Radio Site
› Flexible architecture
Fronthaul 6392
– Optimal baseband
CPRI over Microwave
Router 6000
Router 8000
Router 6000
Router 8000
Fronthaul 6392
Baseband
CPRI over active fiber
solution for every site – Full coordination – Best efficiency – Best performance
Baseband Baseband Baseband
CPRI over passive fiber
Baseband Hotel
Figure 3-47: Ericsson Radio System - Backhaul and Fronthaul
4.4
Enclosure Ericsson’s enclosures are designed with multiple climate options for optimal energy efficiency and operating conditions in all climates. The enclosures have standardized design and open interfaces to support easy installation of third party equipment. Integration with all other building blocks in the Ericsson Radio System guarantees a high reliability and eases site dimensioning during construction and when expanding capacity and functionality. The enclosures are constructed based on years of experience with network operation in environments with earth quakes, dust, moist and seawater. Locks and doors are highly vandal proof. Enclosure Module
6340
6130
6320
6330
6140
6150
Power Module
6610
6302
6306
Figure 3-48: Ericsson Radio System - Enclosure and Power Modules
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Ericsson Radio System Enclosures can be remotely controlled via the Ericsson Network Manager, the same management system that is used for all other elements in the Ericsson Radio System. This makes it straightforward to remotely configure settings and handle alarms. The enclosures in Ericsson Radio System have the flexibility and minimized footprint to meet any site challenge.
Ultra-compact
AC/DC POWER
Highly scalable
AC/DC POWER
Cost efficient
AC/DC POWER
AC/DC POWER
BASEBAND BASEBAND BATTERY BACKHAUL
BATTERY
All-in-one
BATTERY
BACKHAUL
BACKHAUL
Main-Remote
Power/battery
Transmission
Energy storage
Figure 3-49: Ericsson Radio System - Enclosure Module
The Enclosure product line offers a multitude of different configuration options – all within the same product eco-system enabling easier use among installation and maintenance.
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•
A cost efficient All-in-one solution with AC/DC power, power distribution, equipment space and battery back-up in one enclosure on a small footprint.
•
As a Main-Remote configuration it housing baseband and backhaul equipment
•
As a Pure AC/DC power system with distribution and back-up batteries – for supporting other equipment enclosures or site equipment such as Remote Radio Units (RRUs)
•
Supporting large transmission nodes in the backhaul network
•
Can support as Energy storage for sites with poor or no grid that requires extra-long back-up times.
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4.4.1
Enclosure New Family •
Enclosure 6340
•
Enclosure 6330
•
Enclosure 6320
•
Enclosure 6130
•
Enclosure 6140
•
Enclosure 6150
•
Enclosure 6306
•
Enclosure 6307
The figure below highlights the Enclosure 6320 / 6330 / 6340 benefits.
Benefits: › Mast, pole and wall mount › Compact and light weight for easier and simpler site expansion › Perfect choice for dense urban areas with limited site space › Optimized for developing markets
Figure 3-50: Ericsson Radio System - Enclosure 6320 / 6330 / 6340
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The figure below highlights the Enclosure 6150 benefits.
Benefits: › Optimal for greenfield deployment › High internal battery capacity › Up to 20 kW of DC power › Designed for large configurations – Supports up to 21 Remote Radio Units – Baseband – Transmission
› Control via OSS/ENM or Remote Site Management
Figure 3-51: Ericsson Radio System - Enclosure 6150
4.4.2
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Power Products •
Power 6610
•
Power 6302
•
Power 6306
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5
SYNCHRONIZATION IN LTE In LTE deployments, network synchronization is key and solutions need to meet the rigorous timing and delivery requirements that ensure network quality and availability. Synchronization technology and standards are necessary to support LTE deployments. Various synchronization options are available. “Synchronization” ensures the radios in the target LTE eNb are operating within the performance parameters defined by the (3GPP) standard. Synchronization is achieved by delivering a specifically formatted clock signal or signals to the eNb. These signals in turn are used to generate the modulation method’s RF air interface frequency/phase components.
5.1
Why and when Synchronization is needed In the figure below the main reasons for the synch alternatives are listed. › Why Frequency Synchronization?
› Why Phase/Time Synchronization?
– 3GPP specifies frequency stability of 50 ppb on the air interface for GSM, WCDMA and LTE – Minimize disturbance on air interface to secure handover between RBSs – Fulfill tough regulatory requirements connected to the frequency license
– 3GPP specifies 3 µs time difference between Base Stations for LTE TDD – Phase synchronization required in TDD technologies to remove disturbance between downlink and uplink – Time synchronize transmission from different base stations to optimize bandwidth usage and enhance network capacity for certain features
Both FDD and TDD based radio technologies require frequency synchronization Figure 3-52: Why is Synchronization Needed?
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In the Figure 3-53, below gives examples of when Time /Phase synch is needed.
LTE TDD
LTE Broadcast (eMBMS)
Co-ordination Features for Small Cells
Positioning
CDMA Fallback
* Regulatory demands in some countries. Assumes GNSS solution.
Figure 3-53: LTE: Time/Phase Sync Needs
Requirements of Accuracy at air interface (antenna reference point) Positioning Absolute time acuracy of ~+/-100ns * for positioning of E911 calls CDMA Fallback +/-1.5..+/-5 us frame alignment LTE TDD +/-1.5us , cell radius < 3km +/- 5us, cell radius > 3km LTE Broadcast (eMBMS) +/-1,5..10us absolute time accuracy Co-ordination Features for Small Cells +/-1..5us absolute time accuracy for FeICIC, CoMP over X2
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5.2
What are the different types of Synchronization In the Figure 3-54 below we see the three types of synchronization used: Frequency fA = fB Synchronization
fA = fB No Synchronization
TA = 1/fA
TA = 1/fA System A:
TB = 1/fB TB = 1/fB
System B:
Phase
Time fA = fB + t1 = t2
fA = fB + t1, t2 in same instant
Synchronization
Synchronization 2013-01-24 12:00:01
System A:
t1
t1
2013-01-24 12:00:01
System B:
t2
t2 Note: Phase sync does not require knowledge of a common time origin (epoch); Time sync does require knowledge of a common time origin (epoch)
Figure 3-54: A short introduction to different types of synchronization
5.3
What are the solutions for synchronization? A backhaul migration to Ethernet has spawned new standardized synchronization techniques, such as synchronous Ethernet (SyncE) from the ITU, G.8262, and one from the IEEE called Precision Time Protocol 1588-2008 (PTP). Ethernet has rapidly taking over legacy technologies within the carrier infrastructure (e.g. TDM, ATM and SONET / SDH) where synchronization and clock distribution are an integrated part of the technology. Ethernet, originally designed as a ”besteffort” data delivery technology, is now being equipped with synchronization and clock distribution features.
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The SyncE standard is a method for carrying a primary reference traceable clock (PRC) via the Ethernet PHY. This clock provides a very accurate frequency with high stability and minimal wander so it easily can be used to synchronize radios in an LTE FDD basestation. SyncE cannot carry a phase component. When it’s used by itself, then, it’s appropriate for FDD-based radio synchronization
•
PTP(1588v2) is a mechanism for transporting a value of time from a grandmaster clock in the form of a timestamp across packet networks. The syntax of the protocol is master-slave, and it has means for the slave clock to measure packet flight times on the uplink and downlink sides of the path. PTP also can deliver both a phase signal in the form of one pulse per second and frequency.
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The system clock uses the bit rate carried by the synchronization network and drives the frequency of all outgoing timing packets. These could be also generated by a stand alone time server locked to an accurate referenc e (e.g. GPS) The Timing recovery process is based on the arrival time of the packets The information (timestamp) carried by the packets is used to support this operation. Two-way or one-way protocols and same Performance with PTP and NTP when no support from the network is provided
5.4
•
NTP is Network Time Protocol, an Internet protocol designed to synchronize the clocks of computers and other devices to some available time reference. It works over packet-switched variable latency data networks. NTP may be a better alternative than other standards for some systems.
•
TDM, In traditional digital telecommunications networks (TDM), sync was maintained by employing two types of synchronization elements, Primary Reference Clocks and distribution Clocks, over a physical circuit. As networks transition from TDM to packet-based next generation networks, choosing a sync technology becomes more challenging, because packet-based networks do not deliver synchronization naturally as the TDM network elements did. So synchronization (and QoS, quality of service) must be engineered into the packet backhaul.
Ericssons Synchronization alternatives Ericsson provides a number of solutions for synch, presented in Figure 3-55 below. GPS
NTP
PTP
SyncE
PRC
PRC
PRC
TDM, 2 MHz PRC
PTP
NTP
PTP
NTP
TN
Best performance
Most cost efficient
Indoor installation may be an issue
NTP server integrated in RNC Proven for WCDMA over multiple access technologies
PTP for frequency and time sync External master Needs transport network support for time sync
Physical layer sync Needs support in all intermediary nodes
Complementary case Redundant sync source
Figure 3-55: Sync Alternatives
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A table of available Synchronization Options is presented in Figure 3-56 below.
Figure 3-56: Synchronization Options
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6
SECURITY IN LTE Communication via mobile networks is in many countries defined as critical information infrastructure. › From governments/ authorities – Government definition of Critical Information Infrastructures (e.g. Communications, Healthcare Energy, Transport – Operational security requirements and audits
› Examples of policy measures: – US Executive Order 13636 and “Cyber security Framework” – EU
› Cyber security strategy › EU proposed NIS directive › EU NIS framework
– India
› Security requirements and audits on operators. › Mandatory local testing of equipment (from 1 Oct 2013) however alignment with global standards
– Privacy and integrity
Security requirements on mobile networks from regulatory activities Figure 3-57: Policy and Regulation
The awareness of that information is a tradable asset, for example where users are located, their behavior patterns, which web pages are visited and so on, has increased in today’s society. The potential threat to privacy and the integrity together with mobile networks being defined as critical infrastructure have increased and are increasing the requirements on mobile networks form regulatory activities, like government and authorities. Security controls needs to be in place to fulfil a set of these requirements, some optional and some mandatory.
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6.1
Integrated Security Control Ericsson provides INTEGRATED security control solutions for e.g. •
Authentication and Authorization
•
Operational Integrity
•
Protection for data in transit and rest
•
Node integrity and physical security
Authentication and Authorization
Node Integrity and physical security THREATS To Availability To Integrity
PKI
To Confidentiality
Protect data in transit and rest
Certificate Management
RBS Authentication
SEG
Operational Integrity RBS
RBS
RBS
SEG
Figure 3-58: Ericsson provides Integrated Security
In this overview presentation the integrated security control mechanisms are grouped as seen in Figure 3-59 below:
› Air interface security › Transport security › Security in auto integration of small cells in an untrusted environment › Authentication and authorization › Security monitoring › Node hardening and physical node protection › Secure execution environment
* See small cell deployment in untrusted environment seminar Figure 3-59: Security Control Landscape, examples
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6.2
Air interface Security Security functions are applied between the UE and the MME (Core Network security) and between the UE and the eNodeB (RAN security). LTE
LTE
CORE NETWORK
CORE NETWORK
Security Gateway S1 IPSEC
S1/X2
eNodeB eNodeB LTE -Uu LTE -Uu
Ciphering of UE traffic over Air
IPSec Ciphering over transport
Figure 3-60: LTE Ciphering
RAN security consists of integrity protection and ciphering between the UE and the eNodeB. The user plane is protected by ciphering and the control plane by both ciphering and integrity protection. NAS security consists of integrity protection and ciphering of the NAS messages exchanged between the UE and the MME. Encryption is optional, but integrity protection is mandatory by 3GPP. The two cryptographic algorithms are 3GPP based on SNOW 3G and AES.
6.3
Transport Network Security One of the security control mechanism in LTE, WCDMA for transport network security is IPSec ( Internet Protocol Security). IPSec is used for securing IP communication over a non-trusted network. IPSec is an open standard (RFC 4301) and it operates on the Internet Layer in the IP protocol suite. IPSec provide:
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•
Integrity protection
•
Encryption, that protects data from being read in clear text
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•
Replay protection , that protects against attacks where packets are resent or modified
The supported mode of operations are tunnel mode. IPSec is required by 3GPP, but optional for the operator to use. When introducing IPSec a Security Gateway (SEG) is required. The Security gateway is placed between at the border between the trusted and the un trusted zone. The IPSec authentication use digital certificate and a PKI ( Public Key Infrastructure ) is required for certificate management for IPSec.
6.4
Transport and Air Interface Security The green arrows in the Figure 3-60 above show the location of the IPSec deployment in the transport network: For LTE IPSec is offered between the base station and the Security Gateway, over S1/X2. The red arrows shows the air interface ciphering and how it works together with the IPSec, the green arrows, acting as security control mechanisms for different part of the network. For LTE the IPSec is available for macro, micro and pico base stations. Since the air interface ciphering is terminated in the eNodeB, the IPSec is supported for macro nodes as well as small cells.
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6.5
Small Cell Auto integration on untrusted backhaul The new type of deployment scenarios coming from the introduction of small cells, where an untrusted backhaul is used, increases the need for transport security. What is classified as untrusted network is basically up to the operators to decide in their risk analysis, but it can be deployment of small cells over internet, shared transport networks or part of networks where the operators are not in full control of the security. There are a number of impacts to consider when using untrusted backhaul. IPSec is recommended to prevent traffic from being intercepted between the small RBS and the Secure Core and OSS Infrastructure . IPSec is also used to ’hide’ the infrastructure behind the SEG . In other words, the inner IP addresses of the operator nodes are not visible to the public network, only the outer IP addresses. Authentication is also recommended so that the small RBSs shall be able to identify themselves initially as being an Ericsson node and subsequently as being an RBS belonging to a specific operator. The authentication is done using vendor and operator certificates during the auto-integration procedure. Both IPSec and Authentication are supported as an integrated part of the autointegration procedure for micro and pico base stations. › Need for transport security IPSec – To prevent traffic being intercepted between RBS deployed on untrusted networks and the trusted Core/OSS – To ’hide’ the infrastructure behind the Security Gatway (SEG)
RNC
Macro backhaul (Trusted Network)
S/PGw Routed Core (Trusted Network)
› Need Authentication – Nodes shall be able to identify themselves both as a) An Ericsson node Small b) An operator node RBS
›
Auto integration with integrated security controls –
MME
SEG Untrusted Network
OSS complex (Trusted Network)
IPSec and authentication mechanisms are supported as an integrated part of the small cell auto-integration procedure for both micro and pico
Service Service Service Switch
Figure 3-61: Small Cell Auto integration on untrusted backhaul
•
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User authentication and authorization used in access control systems to managing the asset, are key security control mechanisms and addresses the class if human threats, both accidental and deliberate. The key features in our products are:
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Personal login accounts with unique personal passwords – who is the user and is he/she allowed to access?
•
Access control profiles that sets the actions a user is allowed to do on the asset, e.g. is the user allowed restart or reinstall nodes, change parameters, or similar?
•
A centralized point of authentication and authorization, of the user name and password as well as the access profile
•
Have all communication over secure protocols between nodes, like sftp/ftps, LDAPs, https, to avoid tampering or interception
•
The implementations on each nodes varies, please check the roadmaps and CPI per each products for level of security control available
User DB
User
Auth DB
SSH/ SFTP Client
Username& password
AA Server
Query OK+Authorisation NW Element
OSS-RC Figure 3-62: User Authentication, Authorization and Access Control, Example
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6.6
Digital Certificate and PKI infrastructure In mobile networks nodes initiate contacts automatically and set up communication interfaces without manual interventions, as of the small cell auto integration without laptop scenarios on untrusted backhaul. To secure connection, the node needs to verify its identify and set up agree on in which way to encrypted the communication. Digital certificate (i.e. user certificates and Trusted certificate chains) are used for authentication. AA servers (e.g. LDAP server) are used for authorization. The authorization methods could be RBAC (Role Based Access Control) or TBAC (Target Based Access Control). Encryption keys are used, with a public and a private key, to allow for encryption and decryption of the communication. The combination of a digital certificate and a private key is called credentials •
Vendor credentials are only used during Auto-Integration to authenticate the RBS to the Security Gateway (SEG) and OSS applications
•
IPsec credentials authenticate the RBS to the SEG.
•
OAM credentials are used to authenticate the RBS towards OSS applications
In addition to the RBS support for online certificate based authentication, the OSS needs to include support for PKI (Public Key Infrastructure).
› used for Authentication and Authorization › Certificate based identification of Ericsson equipment › Certificate based identification and authorization towards security gateways and OSS
Figure 3-63: Digital Certificate and PKI Infrastructure
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6.7
Real time Security Event Logging To monitor the security in the mobile networks, to detect attacks and security breaches and to quickly be able to stop threats in progress are very important. The node security audit logs records security related events and can be fetched from the nodes for analysis. In addition to the security audit logs , several node in the mobile networks offer a feature called Real Time Security Event logging. This feature streams security events in real time to node external syslog servers allowing for a “real time analysis” of security threats. The security logs can be streamed from multiple nodes/node types to the same syslog server making it possible to triage security attacks on a network level. Quick knowledge of a threat or an attack, makes it possible to take counter actions that can significantly reduce the potential revenue loss connected to the realization of the threat.
› Introduction of security log events in all network elements to enable › triage of security breaches › “application of counter measures” to stop threats in progress › audit trails › In combination with the remote system log gives the operator the capability to in real time securely send security events to a centralized syslog-server
NB, eNB,RNC,TCU/SIU
: NB, eNB,RNC,TCU/SIU
Security Log Server
Analysis
Figure 3-64: Real time Security Event Logging
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6.8
Node Hardening Tightening or increasing the security of an individual node, its interfaces and its entry access point, is termed "node hardening" Node hardening is node specific and is one of the most important processes in securing a site. Node hardening: •
Available features and configurations that impact security
•
State of the product when it is delivered
•
Minimum recommended security actions and settings to set the node in a secure stat
› Examples on node hardening, handling of – Ciphering – Access control lists – IP security – OAM security including user account, password and session – Security loggings – Real time security event loggings – RBS Integration security and parameter settings during integration – Security for port handling on nodes – Risk analyses and vulnerability tests
Figure 3-65: Node Hardening
6.9
Secure execution environment All Ericsson products have a secure execution environment in different forms either using software features or a combination of software and hardware support, depending of hardware generation. The secure execution environment targets:
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Secure storage for sensitive data , for example the encryption keys
•
Securing that code in the node could not be tampered with or that additional code added without control
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Most nodes use so called signed software, which means that the code are not allowed to execute on the hardware unless the software is “signed” in the correct way. The responsible software production unit is the only one that can signs the software so that it can execute in the hardware. Signed software protects against malicious or faulty software to be execute on the node hardware. An additional step which enhances security in the execution environment is the introduction of secure booting, where each booting steps are authenticated before being allowed to execute. The secure booting is a protection against malicious software's, attacking the booting sequence. A high level framework for what can constitute a secure execution environment is defined by 3GPP.
Secure execution environment with for example: – Secure storage – Secure boot – Signed software
Node Integrity and physical security
Protect data in transit and rest
Figure 3-66: Secure Execution Environment
Security needs to be a matter of constant conscious choices. What controls that are the need in your networks depending on the deployment scenarios and the connected risk assessments. New deployment scenarios for small cells on untrusted networks require specific attention on security.
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7
SUMMARY The students should now be able to: 3 Describe the E-UTRAN Architecture 3.1 List the functionality of the eNodeB 3.2 Describe the radio interface techniques, OFDM/SC-FDMA and the physical bit rates 3.3 Discuss Link Adaption in LTE 3.4 Describe the basic principles of MIMO 3.5 Explain the concept of Advanced Carrier Aggregation 3.6 Describe the RBS 6000 Hardware for LTE 3.7 Describe the Ericsson Radio System 3.8 Explain Heterogeneous Network 3.9 Outline on overview level the security in LTE 3.10 Describe the different type of synch in LTE Figure 3-67: Summary of Chapter 3
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4 Key LTE Solutions
Objectives On completion of this chapter the students will be able to: 4 4.1 4.2 4.3
Describe key LTE Solutions Explain the options for Voice; CS Fallback, VoLTE and Wi-Fi calling Describe the LTE Broadcast Service, eMBMS Explain Location services in LTE
Figure 4-1: Objectives of Chapter 4
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1
VOICE AND LTE One of the main drives in the development of LTE was the migration towards an All-IP environment and as such there is no CS core in an LTE network (as seen in the chapter 2). The CS core nodes (MGW, MSC-S) allowed for the provision of CS based services such as voice services but in LTE these nodes do not exist. This means that voice services cannot be supported by LTE in the conventional way. Instead voice services can be provided through IMS with MMTel (commonly referred to as VoLTE) or by making use of existing legacy systems and performing Circuit Switched Fallback (CS Fallback) to these systems when CS services are required. After an operator have set the main strategies, there will be a period in time when the legacy network and the new technology need to coexist. To get a good user experience, some (standardized) mechanisms are needed to bridge between the different technologies. CSFB: Relies on the legacy technology to provide the voice service. LTE will be used for mobile broadband. The terminal drops LTE radio and make phone calls in 2G/3G. No need for IMS/MMTel service engine. ICS: Used in combination with SRVCC, to centralize the voice (supplementary) services to IMS/MMTel. It will give the end user a consistently behavior. It will also reduce the complexity of aligning the service data between the CS and the IMS domain. The mobile get its telephony services from IMS/MMTel even while connected via CS access. SRVCC: Voice over LTE is introduced in islands of good LTE coverage. SRVCC will be needed to hand over a call from PS to CS technology, meaning handover of an ongoing MMTel call in LTE (or HSPA) to CS access.
› Circuit Switched Fall Back (CSFB) – 3GPP TS 23.272
› IMS Centralized Services (ICS) – 3GPP TS 23.292
› Single Radio Voice Call Continuity (SRVCC) – 3GPP TS 23.216 LTE
GSM / WCDMA
LTE
LTE
Figure 4-2: 3GPP Mechanisms for CS Voice/VoLTE Coexistence
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1.1
CS Fallback CS Fallback function in EPS enables the provisioning of the CS services when the UE is served by E-UTRAN. A CS Fallback enabled terminal connected to EUTRAN can use GERAN or UTRAN or CDMA 1xRTT to connect to the CS domain. This can be seen in Figure 4-3.
› Subscribers roaming with preference on LTE access, no CS-voice service available (i.e. IMS is not used as voice engine) › Fallback triggered to overlapping CS domain (2G/3G) whenever voice service is requested › Resumed LTE access for PS services after call completion (cell reselection) LTE island PS PS LTE LTE
LTE CS (+PS) LTE GERAN/UTRAN
Figure 4-3: CS Fallback - Concept
LTE/SAE provides connectivity towards PS domain and supports packet based services only. That implies that traditional CS services such as CS Voice, CS Data, SMS are not supported. In order to provide smooth migration CS Fallback solution is provided by 3GPP. As illustrated in Figure 4-3, LTE coverage is initially only deployed in islands. Outside these islands, the subscriber must receive its services from a non LTE environment. This can either be a HSPA network, over which MMTel is run or a classical CS network without MMTel capabilities. A CS fallback enabled terminal, connected to E UTRAN may use GERAN/UTRAN or CDMA 1xRTT to connect to the CS domain. This function is only available in case E UTRAN coverage is overlapped by either GERAN/UTRAN or CDMA coverage.
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CS Fallback may be used as a generic telephony fallback method securing functionality for incoming roamers as well. 2. CS domain updated of subscribers whereabouts through CS signaling over MME-MSC (LUP, SMS etc.)
1. Subscriber registered in MSC but roam in LTE
CS signaling Packet Core LTE RAN
CSFB Terminal
MME
SAE Gw
SGSN
GGSN
4. Page over SGs-interface
MSS GSM / WCDMA RAN
5. RAN triggers an release with redirect
RC
CSFB Terminal
M-MGw
MSC-S
IM-MGw
MGCF
MRFP
payload
3. Incoming call to subscriber in LTE
6. Page response and call setup over 2G/3G radio
Figure 4-4: CS Fallback MSS as Voice Engine for LTE subscribers
Figure 4-4 illustrates one scenario when providing CS services to an LTE subscriber. Prerequisite for CS Fallback to work is that UE is dual radio capable UE and it is registered in the CS Domain. The ‘CS Fallback to GERAN and UTRAN’ transfers a UE requesting a CS service (a voice call) to another Radio Access Technology (RAT) which can handle a CS connection using the Release with Redirect (RwR) mechanism. The ‘PSHO-Based CS Fallback to UTRAN’ (FAJ 121 3072) optional feature allows the eNodeB to use handover rather than RwR to transfer a UE to WCDMA when a Circuit Switched (CS) fallback is required.
1.1.1
Emergency Call Handling The Emergency Call Support for CS Fallback feature offers the operator the possibility to set separate priorities for doing CS fallback for emergency calls as compared to CS fallback for ordinary voice calls. This allows the operator to direct emergency calls to the network that has the best positioning performance and thus comply to the FCC phase 2 requirements on positioning accuracy for such calls.
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1.2
VOLTE (IMS based MMTEL) VoIP services in LTE are provided by IMS based MMTel (MultiMedia Telephony), commonly referred to as VoLTE. Even if IMS consists of a collection of standalone nodes, they are only useful in a context, and a lot of the functionality is only provided by the combination of several nodes. In nearly all of the customer installations the IMS core nodes and in most of them also the MTAS are present in order to provide MultiMedia Telephony (MMTel) services. It is therefore necessary to secure, verify, and describe the functionality provided by the combination of these nodes, in addition to what is done for the standalone nodes.
1.2.1
IMS and Standardization Open IMS standards are necessary for inter-working. To ensure mass-market consumer acceptance, IMS services need to work across different networks, devices and access technologies. This is enabled through standards-compliant IMS products, verified in an end-to-end environment through interoperability testing between device and infrastructure vendors. The IMS standards define a generic architecture to offer multimedia services. The involved standardization bodies are: 3GPP - (Third Generation Partnership Project) Officially-recognized Standardization Organizations collaborate in the production of evolved Third Generation and beyond Mobile System specifications. The purpose of 3GPP is to prepare, approve and maintain globally applicable Technical Specifications and Technical Reports for: -
An evolved 3rd Generation and beyond Mobile System
-
The Global System for Mobile communication (GSM) including GSM evolved radio access technologies
-
An evolved IMS developed in an access independent manner.
IETF – (Internet Engineering Task Force) is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is the protocol engineering and development arm of the Internet OMA – (Open Mobile Alliance) is the leading industry forum for developing market driven, interoperable mobile service enablers. It is the focal point for the development of mobile service enabler specifications, which support the creation of interoperable end-to-end mobile services. OMA drives service enabler architectures and open enabler interfaces that are independent of the underlying wireless networks and platforms.
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TISPAN - (Telecom and Internet converged Services and Protocols for Advanced Network) The ETSI core competence centre for fixed networks and for migration from switched circuit networks to packet-based networks with an architecture that can serve in both to create the Next Generation Network. Building upon the work already done by 3GPP in creating the SIP-based IMS (IP Multimedia Subsystem), TISPAN and 3GPP are now working together to define a harmonized IMS-centric core for both wireless and wireline networks. CableLabs – Is a non-profit research and development consortium that is dedicated to pursuing new cable telecommunications technologies and to helping its cable operator members integrate those technical advancements into their business objectives. WiFi Alliance - Is an industry-led, not-for-profit organization formed to certify and promote the compatibility and interoperability of broadband wireless products based upon the IEEE 802.11 standard. GSMA - The GSMA represents the interests of the worldwide mobile communications industry. Spanning 219 countries, the GSMA unites nearly 800 of the world’s mobile operators, as well as more than 200 companies in the broader mobile ecosystem, including handset makers, software companies, equipment providers, Internet companies, and media and entertainment organizations. The GSMA is focused on innovating, incubating and creating new opportunities for its membership, all with the end goal of driving the growth of the mobile communications industry. Ericsson IMS is developed with a core offering for both wireless and wireline operators and is a cornerstone for providing converged multimedia services across multiple accesses. It consists of a common core, enablers, support systems and interworking functions enabling operators and service providers to leverage on installed legacy networks, thus reducing cost, while providing key end-user benefits like reliability and security.
What is IMS? • IP Multimedia Subsystem •
All-IP network for multimedia services
•
3GPP standard
•
SIP – main protocol from IETF
•
Access independent
Volte MMTel
Presence Messaging RCS
Standardized IMS Applications
IMS
IP core
Fixed Access
Cable Access
Fixed Wireless
Standardized access to IMS providing: • Access QoS policy control • Emergency call (location) • Lawful intercept
Mobile Access
Figure 4-5: IMS – IP Multimedia Subsystem
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IMS is an architectural framework for delivering IP multimedia to mobile users. It was originally designed by the wireless standards body 3rd Generation Partnership Project (3GPP), and is part of the vision for evolving mobile networks beyond GSM. Its original formulation represented an approach to delivering Internet services over GPRS. This vision was later updated by 3GPP, 3GPP2 and TISPAN by requiring support of networks other than GPRS, such as Wireless LAN, CDMA2000 and fixed line making IMS access independent.
1.2.2
MMTel Basic Service The Multimedia Telephony service offers real-time, multimedia services and enables users to communicate using voice, video and chat in a single or combined manner, and to share files such as images and video clips. 3GPP MMTel standard is followed. It is a global standard based on the IP Multimedia Subsystem IMS standards, specified by 3GPP and embraced by standardization in TISPAN. The Slide below presents the MMTel Basic Services.
› Usage of different media components such as audio, video and text in a single or combined way. › Supported media types: – Voice – Video – Text chat – Sharing
Figure 4-6: MMTel Basic Service
To ease the integration with the Internet, IMS as far as possible uses IETF (i.e. Internet) protocols such as Session Initiation Protocol (SIP). According to the 3GPP, IMS is not intended to standardize applications itself but to aid the access of multimedia and voice applications across wireless and wireline terminals. This is done by having a horizontal control layer that isolates the access network from the service layer. Services need not have their own control functions, as the control layer is a common horizontal layer. The IMS standard defines a generic access agnostic architecture to offer converged multimedia services, for example Multimedia Telephony (MMTel) for telephony services, such as e.g. voice. With the IMS architecture, a single service can be provided over many access types. The IMS standard support a multitude of access types such as GSM, WCDMA, wire line broadband (DSL, GPON etc), wire line narrowband (for PSTN replacement via e.g. a MSAN), cable, 3GPP2 access types such as CDMA EVDO and now also E-UTRAN/EPC.
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IMS can interconnect to other IMS systems, other proprietary VoIP systems based on SIP or H.323 and PSTN/PLMN. This allows a MMTel user to communicate with end-users on legacy telephony systems. The packet core evolution is transparent to IMS meaning that any inter-access mobility is invisible to IMS applications. A stable IP POP is retained regardless of which IP access is used. From an IMS perspective, once the terminal has attached to the Packet core network it can start utilizing the IP based services such as MMTel. The IMS Registration capability is a function that allows a user to register/de-register (login/logoff) with the IMS network and is a pre-requisite for allowing the user to initiate and receive IMS services. Prior to the registration, the user shall be provisioned with a subscription to the network and the UE configured to use the P-CSCF as its outbound proxy or alternatively use a P-CSCF proxy discovery functionality in P-GW. In addition to the P-GW functionality, it is possible to perform charging coordination with the IMS services. Charging coordination between the LTE bearer layer and IMS service nodes can be supported using the 3GPP R7 Policy Control and Charging, PCC, architecture as specified in TS23.203.
1.2.3
The MMTel Service Platform MMTel is a converged telephony solution that allows the operators to offer one service over many access types. This is the reason MMTel is based on IMS. The MMTel specification specifies a set of end-user communication capabilities (media types) that are used to build end-user services from. The Multimedia Telephony service offers real-time, multimedia services and enables users to communicate using voice, video and chat in a single or combined manner, and to share files such as images and video clips. 3GPP MMTel standard is followed. It is a global standard based on the IP Multimedia Subsystem IMS standards, specified by 3GPP and embraced by standardization in TISPAN.
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The figure below presents the Volte/CS Architecture.
CS Core
IMS
EPS
Figure 4-7: Volte/CS Architecture
The basic communication capabilities standardized in MMTel allows media transfer controlled by a single SIP session. Two or more users can communicate in real-time using different media components.
1.2.4
Ericsson IMS Portfolio Overview Ericsson IMS facilitates complete IMS network deployment including the following:
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IMS nodes and applications used as components supporting different Business Solutions and targeted customer solutions
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Ericsson IMS Professional Services
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Illustrated below are the nodes used to build operator solutions using Ericsson IMS. The actual nodes to be offered and deployed depend on customer needs and existing installed base. Solutions
Mobile Unified Communication
Mobile Telephony Evolution with VoLTE Visual Communication
Databases
PSTN to IP
Converged Transit Evolution
Application Enablers
HSS
MTAS
Interworking BCE
EMe
Control and Media
CUDB
IP Works
xDSL
CSCF
SBG
Fiber
Global Services
Flexible RCS
Support Systems
MGC
Cable
WCG
HSPA
MRS/ M-MGw
Wi-Fi
LTE
CUDB = Centralized User Database WCG = Web Communication Gateway MRS = Media Resource System
Figure 4-8: IMS and Related Portfolio
Ericsson IMS is developed as a core offering for both wireless and wireline operators and includes also support for operators looking for converging networks. It provides common control and media handling, common enablers, support systems and interworking functions enabling operators and service providers to reduce cost, leverage on installed legacy networks while providing key end user benefits like ease-of-use, reliability and security. Ericsson provides standard-based IMS nodes to be used to realize specific customer solution. IMS Professional Services project is offered as the supporting activity for the customer to realize the wanted target solution. Ericsson IMS offerings are based on Ericsson products verified in end-to-end environment.
1.2.5
Ericsson IMS Nodes
1.2.5.1
Control and Media Control and Media encompasses IMS nodes which secure high carrier grade characteristics and uniform SIP-based traffic handling.
1.2.5.1.1
CSCF – CALL SESSION CONTROL FUNCTION Handles the supervision and control of the accessed IMS network and together with IPWorks manages the routing and sessions in the IMS network.
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1.2.5.1.2
MGC – MEDIA GATEWAY CONTROL FUNCTION Provides the signaling level interworking function between circuit switched telephone network (GSTN) and packet switched multimedia networks. The MGC is adapting the call/session level signaling between the two networks and controlling Media Gateway (MGW) nodes.
1.2.5.1.3
MRS – MEDIA RESOURCE SYSTEM It provides all media handling related functionality through a single product. Supported functionality includes:
1.2.5.1.4
•
Media Gateway (MGW) for handling payload exchanged with the GSTN network
•
Media Resource Function (MRF) for handling all media required for IMS services. MRF function can further be decomposed into Media Resource Function Control (MRFC) and Media Resource Function Processor (MRFP), where the optional MRFC functionality can be complemented or exchanged with the same functionality provided in another node (e.g. MTAS) in case when that option provides for simplified and more efficient network architecture.
•
Border Gateway Function (BGF) that ensures media plane security, NAT/FW traversal, address and port translation (NAPT) and other critical functions for real-time IP stream towards other networks as well as towards access networks. The Access Transfer Gateway Function (ATGW) is implemented as a part of BGF functionality, providing the SRVCC anchor point for media in VoLTE.
SBG – SESSION BORDER GATEWAY Provides the Network Security, Topology Hiding, Interoperability, Quality of Service and Service assurance, hosted NAT/FW traversal, address and port translation (NAPT) and transcoding for real-time IP-streams at the edge of the network. SBG also supports encrypted media (secure RTP and MSRP) for unsecure access networks like Wi-Fi. SBG functionality for context of VoLTE deployments is enhanced by adding ATCF (Access Transfer Control Function) according to the 3GPP R10 SRVCC definition, which brings lower voice interruption delay during the access transfer. SBG can be located either at network borders (N-SBG) or on the access side of the IMS Network (A-SBG). The SBG includes control of the BGF functionality provided through MRS.
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1.2.5.1.5
WCG – WEB COMMUNICATION GATEWAY Provides network based abstraction of the IMS/SIP signalling protocol for RCS and voice/video type of services and thereby enables many different consumer clients and devices to access the IMS network and services using HTTP/REST based API’s. It contains the SIP stack and thereby eliminates the need to have one on every device.
1.2.5.2
Application Enablers Application Enablers include products performing vital and specific functions that can be used generically to support a number of applications. SIP based application servers for IP and multimedia meet all necessary requirements posed by large commercial networks and have been designed for PSTN transformation and Voice over LTE evolving to full converged broadband communication.
1.2.5.2.1
MTAS – MULTIMEDIA TELEPHONY APPLICATION SERVER An IMS application server for first-line voice and multimedia communication services according to 3GPP MMTel and TISPAN Simulation Services specifications. It is a convergent application server with which operators are able to run first-line communication service for both fixed and mobile networks. It supports Voice over LTE (VoLTE) according to GSMA IR.92 and Conversational Video Service according to IR.94, including Service Centralization and Continuity (SCC). MTAS also supports Scheduled Conference application server (Conf AS) and MRFC functionality. Support for PBX connections for business trunking scenarios is planned through the new Business Trunking AS component.
1.2.5.2.2
PGM – PRESENCE, GROUP AND DATA MANAGEMENT SERVER PGM is a server that enables presence, group and data management functionality. This functionality can also be used by other applications meaning that they don’t need to implement this separately but instead can use the services enabled by the PGM server.
1.2.5.2.3
BCE – BUSINESS COMMUNICATION ENABLER It is a set of applications that support Unified Communication (UC) offerings to operators addressing the enterprise market. BCE supports Visualcom with Conference Booking and Management in its first commercial release.
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BCE will extend functionality offered in MTAS by enhancements focusing on the unified communication need of business users. Unified Communications encompasses all modern communications options like messaging, business voice, presence and conferencing into one integrated solution that is intuitive and easyto-use.
1.2.5.2.4
EME – ENRICHED MESSAGING It provides IMS messaging (IMS-M) and Gateway services and enables targeted deployment in IMS scenario including integration with existing legacy messaging services. EMe is based on open industry specifications defined by 3GPP, OMA IM SIMPLE and TISPAN. The IMS messaging services enable the next generation of messaging services over IMS technology, including Multimedia, Voice & Videomail, IMS Chat, IM and Group Messaginge. The Gateway services ensure service continuity between the different messaging services, such as SMS and MMS, through interworking functionality.
1.2.5.3
Databases Databases provide convergent solutions for IMS subscriber management and security.
1.2.5.3.1
HSS – HOME SUBSCRIBER SERVER It manages the subscription profile in IMS networks, serving both wireline and wireless access domains.
1.2.5.3.2
CUDB – CENTRALIZED USER DATABASE It is a real time database to centralize subscription data. CUDB provides a single point of access and administration to the subscriber data. CUDB node is based on a Distributed Cluster Architecture which guarantees high capacity. CUDB ensures data consistency and integrity and redundancy mechanisms. The physical and logical distribution of the data is transparent to any data user. Within the IMS context, the CUDB handles the storage of IMS user profiles (transparent and non-transparent) managed in HSS-FE (Front End) servers. The CUDB can be implemented using geographic redundancy.
1.2.5.3.3
IPWORKS IPWorks delivers centrally managed Domain Name System (DNS), Telephone Number Mapping (ENUM) and Dynamic Host Configuration Protocol (DHCP) services for mobile and wireline IP networks.
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1.3
Portfolio Related to IMS In order to provide the complete customer solution Ericsson complements IMS nodes with additional components, many of them frequently possible to reuse from the already existing customer deployment. This way customer investment gets secured for the future and provide for the smooth evolution of current offerings into the multimedia broadband communication.
1.3.1
Interworking The interworking role is to protect the boundary of the IMS network and adapt the IMS session to the surrounding network environment when needed. The following Ericsson products have IMS interworking support:
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MSS (Mobile Softswitch) – the signaling level inter-working function between circuit switched telephone network (GSTN) and packet switched multimedia networks is provided through the Media Gateway Control Function, MGCF, which is a logical node implemented in MSC-S.
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SAPC (Ericsson Service-Aware Policy Controller) – a Policy Management Framework required for a wide range of IMS and non IMS services. The main policy types enabled are centralized policy management for access control to services and QoS control per subscriber and service basis.
•
DSC (Diameter Signaling Controller) – is the network component to secure and centralize Diameter communication with other roaming partners and to increase the operation efficiency and reliability of the internal Diameter signaling network.
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TSS (Telephony Softswitch) – provides support for PSTN/ISDN (local, transit and international) services in emulation mode (100% replicating existing PSTN/ISDN services). The combination of TSS and MMTel is a very powerful and flexible solution offering in situations where full PSTN/ISDN support is wanted in combination with evolution towards VoIP and MultiMedia services.
•
EDA (Ericsson DSL Access) – provides support for PSTN Transformation to provide SIP-to-Copper conversion in order to take care of some specific cases like coin boxes and other special legacy equipment. Implements TISPAN MSAN (Multi Service Access Node) functionality.
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1.3.2
Support Systems The IMS Support Systems consist of products and/or solutions that are required to support the provisioning, billing and operation & maintenance IMS applications and networks as well as additional components for the specific offerings. The following Ericsson products can be part of IMS support systems:
•
OSS (Operation Support System) – Provides sub-network management of the IMS network and nodes including fault, performance and configuration management. Access, core and service layer components are managed using the same framework within a centralized operator management site.
•
EMM (Ericsson Multi Mediation) – provides a central point for collection, processing and distribution of charging information. Typically the system is placed between the operators’ communication network and the business support network, with the possibility to use distributed agents and collectors in the network.
•
EMA (Ericsson Multi-Activation) – provides a powerful service life cycle management permitting a simplified introduction, integration and operation of a service during its life time and a single provisioning point of subscription data to IMS and non-IMS servers in a multi-vendor network.
•
ADC (Automatic Device Configuration) – enables the detection of mobile devices at attachment to GSM or GPRS domain, the configuration setting of IMS enabled devices for instant access to PS and IMS network components and additionally supporting an implicit provisioning of users to IMS and non-IMS applications supported by the detected device.
•
AFG (Authentication Federation Gateway) - consists of two modules, XDM Aggregation Proxy (XDM AP) and Bootstrapping Server Function (BSF).
The Aggregation Proxy authenticates IMS clients and provides a single-point-of-entry for access to XML documents on XDM servers (i.e. MTAS and PGM). The Aggregation Proxy supports authentication mechanisms for both HTTP and SIP traffic. The Bootstrapping Server Function (BSF) module supports the Generic Bootstrapping Architecture (GBA) authentication in 3G and 4G networks. GBA is standardized in 3GPP •
VPN (Ericsson Virtual Private Netwotk) – provides a solution that
allows IMS core networks to control voice traffic using SIP enabled PBXs. Ericsson VPN Business Trunking introduces
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VoIP connectivity through IP-PBXs. By replacing the existing PRI line connections with IP trunks, new IMS applications can be introduced without the risk of introducing new business models within the enterprise offering. •
PGS (Personal Greeting Application Server) – performs the call control within the Ericsson Multimedia Ringback solution enabling replacement of the legacy network alerting tone by audio, picture or video content for consumers, enterprises and advertisers.
•
MPS (Mobile Positioning System) – supports IMS convergence
scenarios with support for positioning of users in wire line networks. The MPS today provides the 3GPP Location Retrieval Function (LRF) and the Routing Determination Function (RDF) service needed for routing of Wireline IMS emergency calls according to 3GPP. In future version it is planned to add support for IMS Emergency Sessions over GPRS/EPS/Wi-Fi access. Also support of additional protocols towards Emergency Centers is planned. •
ECE (Ericsson Composition Engine) – is a multimedia service
environment with a focus on Next Generation Intelligent Networks (NG-IN) domain. It supports legacy IN applications based on IN protocols such as INAP CS1+, CAPv1.4 and MAPv3 AnyTimeInterrogation (ATI). In addition IMS/IP support is provided based on the SIP over ISC interface. Applications hosted on the Composition Engine can be converged, i.e. serving both circuit switched networks (PLMN/PSTN) and IMS networks. For IMS it is referred to as SCIM (Service Capability Interaction Manager) or service broker as specified by 3GPP.
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A reference set of capabilities includes the following : •
Transfer of real-time speech (full duplex);
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Transfer of real-time video (simplex, full duplex), synchronized with speech if present;
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Transfer of real-time text;
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File transfer;
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Video clip sharing, picture sharing, audio clip sharing. (Transferred files may be displayed / replayed on the receiving terminal for specified file formats.)
Another important part of the standardized service set is a standardized NNI (Network to Network Interface). This will enable operators to interconnect with each other and that one user belonging to one operator can communicate with a user belonging to another operator. There are also a number of standardized legal requirements such as functions for lawful intercept, emergency call etc. The standardized telephony services defined by 3GPP and TISPAN for MMTel are implemented in MTAS (Multimedia Telephony Application Server). Other standardized network functions in MMTel are codecs, clients and radio optimizations. Basic voice and video calls can be implemented with only the IMS Core nodes but in order to support the supplementary services standardized in MMTel the MTAS is needed. These communication capabilities together with the supported supplementary services can be used to realize the set of end-user services mentioned below. Real-time End-User Services -Voice call - Video call: Video call is an end-user service which realizes a voice and video communication method between two or more peers. The video communication is full-duplex and time synchronized with the voice stream. One peer may be a machine, e.g. an answering machine. A call between three or more peers is sometimes referred to as a Video Conference. The typical use case for a Video Call is a communication session in which the peers can see each other. - Video share: Video share is an end-user service which realizes a voice and video communication method between two peers. The video communication is simplex and is usually not time synchronized with the voice stream. A typical use case for video share is a communication session in which one for the peers wants to show the other peer something that is happening in his/her surrounding.
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- TTY: TTY is an End-User Service which realizes a tele-typewriter which is typically used by deaf people to communicate. Non real-time End-User Services: -Image/Video clip/Audio clip share: Image share, Video clip share and Audio clip share are end-user services that are special cases of File transfer. Image/Video clip/Audio clip share only happens during a Voice call. In Image Share an image captured by the sending terminals camera is sent to a receiving terminal. In Video clip/Audio Clip share, video clips or audio clips stored in the sending terminals memory are sent to a receiving terminal. Rendering capabilities are guaranteed and rendering of the media is expected to happen automatically upon reception of the file. It can be noted that the audio clip share and video clip share service need the possibility of local mixing of the audio streams from the clip with the ongoing voice call. The receiving user may or may not be offered to store the received media file. -File transfer: File transfer is an end-user service which gives the possibility to transfer one file from one end-user to another. The file can be of any sort. The typical File Transfer case is that the receiving user is offered to store the file transferred in the communication in the receiving user’s terminal. -Chat: Chat is an end-user service which realizes a communication method in which text or multimedia messages are sent within a communication session between two or more peers. The text or multimedia messages are always first composed by the end-user. After a message has been composed the end-users press a “send button” to send the message. The end-user perception of a Chat service is that there is a communication session related to the other user(s) he/she tries to communicate with. The messages are delivered directly and therefore an end-user in a Chat session may have higher expectations of an interactive communication with the other peers than an end-user using the SMS/MMS service. The communication capabilities can be subjected to a set of supplementary services. For instance, it is possible to do video conferencing; you can choose to do communication barring on MMTel. Example of Supplementary Services (included in MMTel 3.0): - Conferencing - OIP/OIR/TIP/TIR (O: Originating, T: Terminating, I: Identity, P: presentation, R: Restriction) - Communication Diversion - Communication Barring - Communication Deflection - Communication Hold/Resume
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- Anonymous Communication Rejection - Calling Name Presentation - Communication Waiting
1.3.3
Ericsson Enriched Communication Services The Ericsson Enriched Communication solution enables creation and delivery of new and compelling services in a modular and evolutionary way, according to operator needs. The business solution offers complete network functions for an enriched communication service launch. New services like chat, group messaging and large file transfers can be introduced using the mobile phone’s native support as well as conversational, or one-way, video sessions. The new IP-based services are globally interoperable across different device brands. The services can also be delivered to a secondary device such as a tablet using a common phone number. The Ericsson Enriched Communication solution is the Ericsson realization of the services defined by the GSMA Rich Communication Services (RCS) Release 5.3 specifications (RCC.07), and Enriched Calling (RCC.20). Ericsson Enriched Communication is a commercial solution where the Enriched Messaging (EMe) application server is used together with Ericsson IMS core nodes and MTAS to deliver evolved communication experiences. The solution is aligned with the vision of the GSMA Network 2020 programme, including Rich Communication Suite (RCS) and VoLTE evolution that allow the implementation of new exciting consumer services using the 3GPP IMS and OMA industry standards. The new enriched VoLTE experience will let users enjoy a more user friendly and intuitive service: • Personalize your calls and let people know why you are getting in touch before they answer: add importance, a subject, your current location and any photo to the call •
Share pictures, location or add a video during the call, without hanging up
•
Find everything you shared or received during calls in your logs
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Get all your SMS and chat replies back in one single inbox and in one message thread per contact
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Chat with your friends and family and have as many group chats you like at the same time
Share your favorite moments within a group conversation or send a voice note when you’re tired of typing long text messages
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Since this is an interoperable industry standardized solution there is no need for consumers to download a new communication App client to get the new enriched communication experience. Leading device manufacturers deliver this new user experience from factory together with VoLTE as an integrated experience in the phones standard dialer and messaging client. Users with other device models can also benefit from the new services by download and install a separate App.
1.3.4
VoLTE Architecture In VoLTE, the different media types and signaling have different characteristic requirements that need to be fulfilled. Please see figure below. Voice is deemed to be the most important media flow to get across the system. Therefore in case of congestion, the VoLTE full duplex speech media type should be prioritized. That means that the voice media should always be mapped to a separate EPS bearer. SIP signaling is used for signaling between the UE and the IMS domain. This should also be protected against congestion by being mapped to a separate EPS bearer. This is the default EPS bearer specified by IR.92 that is used for all the SIP messages, including the SMS over IP. Following the GSMA recommendations, the QoS requirements and the additional characteristics requirements stated on voice and SIP signaling protection, the VoLTE service is separated to 4 different EPS bearers:
•
SIP (incl. SMS over IP) on QCI5
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VoLTE full duplex speech on QCI1
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VoLTE real time video on QCI2 or alternatively QCI 6-9 for no GBR (for video calls)
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VoLTE real-time text communication on QCI9
The VoLTE real-time text media is mapped to a best effort bearer with QCI 9. It is believed that the best-effort EPS bearer is good enough to meet the real-time text delay requirements plus it allows for very low data loss rates. For an IMS session request for a Conversational Voice call (originating and terminating), a dedicated bearer for IMS-based voice must be created utilizing interaction with dynamic Policy and Charging Control. PDN Connection establishment can be caused by a SIP registration request. A default bearer must be created when the UE creates the PDN connection to the IMS well known APN. A standardized QCI value of value of five (5) must be used for the default bearer that is used for IMS signaling. The network must initiate the creation of a dedicated bearer to transport the voice media. The dedicated bearer for Conversational Voice must utilize the standardized QCI value of one (1).
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The above mentioned principles are summarized in Figure 4-9, which also depicts the Ericsson VoLTE end-to-end solution. • • • • •
Mobility management Bearer management Inter-MME and IRAT mobility SR-VCC functionality Emergency call support
• • • •
• • • •
Subscription/user data Keys exchange (IMS-AKA) Default APN provisioned Maintain knowledge of used Packet core node (T-ADS)
Enables Bearer QoS Control Set QoS for each Service Data Flow Define Charging for each Service Data Flow Notification of bearer events to Application Function (AF)
S6a • Radio Bearer Realization • Admission control, RLC-UM, Scheduling, DRX, RoHC • Broadcast information • Positioning
MME
Sh
Well Known IMS APN P-CSCF Discovery External IP PoP IP address allocation Policy enforcement
HSS Application Server for MMTel
Rx
Gx S5/ S8
S1-U eNodeB
ISC • I: Home network entry point for SIP registration • S: session control services for the UE
PCRF
SGi
SGW
MTAS
Cx
S11
S1-MME
e-Uu
• • • • •
PDN GW
Mw Gm
I-/SCSCF
P-CSCF /
Signaling Bearer (Default) , QCI=5
SIP (SDP) Voice (RTP) RTCP Video (RTP) RTCP
Mb
Dedicated Voice Bearer , QCI=1 Dedicated Video Bearer , QCI=2/6
Ut
Signaling Bearer (Default) , QCI=9
XCAP
E-UTRAN
EPC
BGF / MGw
• First IMS (MMTel) point of contact for the UE • Located in the home or a visited network. • Application Function
• Gateway for Media
IMS
Figure 4-9: LTE/EPC/IMS Architecture example
The IMS architecture and the involved nodes are explained in the following paragraphs.
1.3.5
IMS Architecture IMS is an architecture designed to support the Control Layer for packet based services, which uses the bearer services of the Access Network to support the media associated with the service. IMS is access agnostic and as such is independent of the access technology used. In a multi-access environment it ensures service availability to all Access Networks (subject to the limitations of the Access Networks, of course). The IMS nodes can be split into 3 groups of elements:
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Database Elements (HSS, SLF)
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IMS Control Elements (P-CSCF, I-CSCF and S-CSCF)
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Control Plane Interworking Elements (MGCF, BGCF and SGW)
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1.3.5.1
Database Elements HSS (Home Subscriber Server) The main database element is the HSS (Home Subscriber Server). This element is an evolution of the HLR element. The HSS contains the features of the HLR (subscriber data and authentication data) and other functions such as Location Register, IMS Service Profile Processing and IMS Subscription and Authentication Data. The HSS is accessed by the I-CSCF, the S-CSCF and external platforms. The HSS uses the Diameter protocol with the Diameter Multimedia Application Extension. SLF (Subscription Locator Function) This database is accessed by the I-CSCF and the S-CSCF in order to obtain which HSS stores the user data when more than one HSS is present in the network. The query contains the identification of the user and the response contains the HSS that stores the data for the specific user.
1.3.5.2
IMS Control Elements The three IMS Control Elements are nodes that act on the control (SIP) signaling flows. These nodes provide Call Session Control Functions (CSCF) and each separate node (Serving, Proxy and Interrogating) has a different role and function. S-CSCF (Serving Call Session Control Function) The Serving-CSCF is the node that performs the session management within the IMS network for the UE. The S-CSCF operates in a stateful manner. The S-CSCF also ensures end-to-end reachability for users and services by interacting with other CSCFs, SIP servers and application servers. The S-CSCF also authenticates the user. The S-CSCF is the main control point for services. The S-CSCF enforces the rule set for services based on the general policy of the operator and the user’s subscription parameters. The S-CSCF may reject a service request according to these factors. The S-CSCF decides on the handling of service requests from the user based on the user’s profile (provided by the HSS during registration). Where the services of an Application Server are required to complete the requested service, the SCSCF forwards the request to the appropriate Application Server either based on the user’s profile or based on the operator’s local policy.
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The S-CSCF is always located in the home network. There can be several SCSCFs in the network. They can be added as required based on the capabilities of the nodes or the capacity requirements of the network and if required can be assigned dedicated functions. The management of S-CSCFs in the IMS network is dynamic and the I-CSCF can allocate the S-CSCF for a user at registration time. The S-CSCF may be chosen based on the services requested or the capabilities of the mobile. One key advantage of this architecture is that the home network provides the services and service features. This means that the user’s configurations are always the same and are always provided by the home network operator. The user is not restricted to the capabilities of the visited IMS network as is seen in the current wireless network (i.e. if an MSC does not support a feature that one has subscribed to, he will not be able to use that feature). However the user is still limited by the visited access network capabilities. P-CSCF (Proxy Call Session Control Function) The Proxy-CSCF is the entry point towards the IMS network from any access network. The assignment of a P-CSCF to a user is determined by the access network configuration. In the case of LTE the allocation takes place at PDP context activation, where the UE may use a DHCP query to obtain the list of PCSCFs or the UE is provided the IP address of the P-CSCF by the GGSN in the PDP activation message. The P-CSCF is located in the same PLMN as the GGSN. The P-CSCF is a stateful SIP proxy and all signaling between the user and the IMS system is routed through the PCSCF. The P-CSCF also enforces the routing of signaling messages through the user’s home network. The P-CSCF is responsible for sending the first SIP message (SIP registration query) towards the corresponding I-CSCF, based on the domain name in the registration request. After successful completion of the registration procedure, the P-CSCF maintains the knowledge of the ‘SIP Server’ (the serving S-CSCF, located in the home network) associated to the user, and forwards all requests from the user toward it. The P-CSCF is responsible for establishing a security association with the user, which it maintains for the lifetime of the ‘connection’. Once the security association is established, it is responsible for receiving and validating all session requests. The P-CSCF also includes the Policy Decision Function (PDF) which authorizes the use of bearer and QoS resources within the access network for IMS services. The P-CSCF is always located in the same network as the GGSN is located. Therefore, both the GGSN and the P-CSCF are located either in the visited PLMN or the home PLMN. Note that in roaming scenarios the SGSN is always located in the visited PLMN. I-CSCF (Interrogating Call Session Control Function)
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The Interrogating-CSCF is the first point of contact within the home network from a visited network or external network. Its main job is to query the HSS and find the location of the S-CSCF. The functionality is similar to that of a Gateway MSC. The I-CSCF may act as a hiding entity into a home network's IM subsystem, in order to mask the internal configuration of the home network's environment from external interrogating devices – which hides such things as the configuration, capacity and topology of the network to prevent roaming partners from discovering each other's network configuration. However the use of this function alters the behavior of signaling messages in a manner not compliant to the use in the Internet world. This discussion is on-going in the standards organizations at the time of writing.
1.3.5.3
Control Plane Interworking Elements MGCF – Media Gateway Control Function The Media Gateway Control Function (MGCF) is a gateway that enables communication between IMS and CS users. All incoming call control signaling from CS users is destined to the MGCF that performs protocol conversion between the ISDN User Part (ISUP), or the Bearer Independent Call Control (BICC), and SIP protocols and forwards the session to IMS. In similar fashion all IMS- originated sessions toward CS users traverses through MGCF. MGCF also controls media channels in the associated user-plane entity, the IMS Media Gateway CIMS-MGW.
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BGCF – Breakout Gateway Control Function The Breakout Gateway Control Function (BGCF) is responsible for choosing where a breakout to the CS domain occurs. The outcome of a selection process can be either a breakout in the same network in which the BGCF is located or another network. If the breakout happens in the same network, then the BGCF selects a Media Gateway Control Function (MGCF) to handle a session further. If the breakout takes place in another network, then the BGCF forwards a session to another BGCF in a selected network. SGW – Signaling gateway A signaling gateway (SGW) is used to interconnect different signaling networks, such as SCTP/IP-based signaling networks and SS7 signaling networks. The SGW performs signaling conversion (both ways) at the transport level between the Signaling System No. 7 (SS7)-based transport of signaling and the IP-based transport of signaling (i.e., between Sigtran SCTP/IP and SS7 MTP). The SGW does not interpret application layer (e.g., BICC, ISUP) messages. The SGW is often included in the MGC.
1.3.6
Mobility - Single Radio Voice Call Continuity (SRVCC) When a UE with an ongoing VoLTE call is moving out of LTE coverage, SRVCC is used to handover the call to the CS domain of the underlined 2G or 3G network. SRVCC allows voice call continuity between IMS over PS access and CS access for calls that are anchored in IMS when the UE is capable of transmitting / receiving on only one of those access networks at a given time. UEs have to specifically support the SRVCC function (defined as a 3GPP SRVCC UE). In order to facilitate the session transfer (SRVCC) of the voice component to the CS domain, the IMS MMTel sessions need to be anchored in the IMS. The MME receives a handover request from E-UTRAN with the indication that this call is for SRVCC handling, and then triggers the SRVCC procedure with the MSC Server enhanced with SRVCC via the Sv reference point (The Sv reference point provides SRVCC support between 3GPP E-UTRAN and 3GPP UTRAN/GERAN) if MME has SRVCC STN-SR information for this UE.
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The Figure below presents the SRVCC (Single Radio Voice Call Continuity) Handover.
GSM
GSM
Circuit switched CORE IMS/MMTEl Telephony
3G
WCDMA
HSPA
Packet Core LTE
LTE
INTERNET
*QCI=1 LTE
SRVCC handover CS coverage
Figure 4-10: SRVCC (Single Radio Voice Call Continuity) Handover
MSC Server enhanced for SRVCC then initiates the session transfer procedure to IMS and coordinates it with the CS handover procedure to the target cell. MSC Server enhanced for SRVCC then sends PS-CS handover Response to MME, which includes the necessary CS HO command information for the UE to access the UTRAN/GERAN.
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1.4
Wi-Fi Calling Wi-Fi calling extends VoLTE by including support for Wi-Fi as an access type for both voice and video calls. It uses the same IMS telephony client, and supports mobility between LTE and Wi-Fi accesses, making the resulting user experience a seamless one. As illustrated in Figure 4-11, Wi-Fi access can be used for telephony services for several subscriber and enterprise scenarios. However, the bulk of current implementations and the primary use case for Wi-Fi calling are to complement indoor environments where cellular network coverage is limited. This use case may also apply to small business premises. Operators are also considering using this technology to provide users, traveling outside their home network, with access to the IMS telephony services of their home network over Wi-Fi networks that are commonly found in hotels, airports, shopping malls and cafés. Wi-Fi calling offers users a simple solution for voice and video calls – one that is fully integrated with modern smartphones and does not require any additional apps or downloads.
When roaming: Bring operator provided service
Home Wi-Fi access point
3GPP access
Untrusted Wi-Fi
Hotel abroad
Untrusted Wi-Fi
Seamless handover of
Homes with limited 3GPP coverage
voice and video calls
Cellars, basements, thick walls, etc.
between LTE (VoLTE) and untrusted Wi-Fi
Small office/business with limited 3GPP coverage
Figure 4-11: Wi-Fi Calling Use Case examples
As illustrated in Figure 4-12, the Wi-Fi calling solution follows the same architecture blueprint as VoLTE, except for the introduction of a new node in the EPC, the WMG (Wi-Fi Mobility Gateway, or ePDG (old name)). Some modifications to the IMS are also necessary to handle the different nature of WiFi compared with LTE and CS accesses.
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Wi-Fi calling is being profiled in GSMA PRD IR.51. S6a
Um / Uu A
Mw / I2
Abis / Iub BSC RNC
BTS NodeB GSM / WCDMA
HSS SWx
A / IuCS
Sh
E/Gd MSS MGCF
W MTAS
Sv
ISC S1-MME Mw
SRVCC handover
MME
Gm
SBG
B
CSCF
Iq
S11
Mb
Mb e-Uu
S1-U EPG
eNodeB
MRS Mb
LTE S2b
LTE – Wi-Fi handover A
Mw / Mg / Mx
PCRF Gx
A
EMe
S6b
SWu Wi-Fi AP Wi-Fi
WMG /ePDG
SWm
AAA
ePDG is renamed to WMG (Wi-Fi Mobility Gateway) in L15
Figure 4-12: Simple add-on to VoLTE Deployments
The Wi-Fi calling solution is an extension of the EPC architecture and allows any Wi-Fi network to be used to access the EPC, which the 3GPP standard refers to as untrusted accesses. The WMG node at the border, which can be found by a device through a DNS lookup, acts as the gateway between the public internet and the rest of the operator’s EPC. To connect to the WMG over the Wi-Fi/ internet connection, a device uses the IETF protocols IKEv2 and IPsec. These protocols provide the connection with integrity and confidentiality, implying that any type of internet connection, even an open Wi-Fi hotspot, can be secured. The IKEv2 protocol uses the credentials stored on the SIM card to automatically set up the IPsec tunnel between the device and the WMG. As a result, no additional action is required by the user, which enhances the seamless experience. The WMG gateway fetches the security keys/vectors and subscription information from the HSS via an AAA node. Handover of calls between LTE and Wi-Fi is enabled by routing Wi-Fi calling traffic to the IMS through the Evolved Packet Core (EPC), which results in a scalable deployment opportunity for network operators. When a handover takes place between LTE and Wi-Fi, the device retains its IP address, and any policies assigned to the connection will remain intact. Using this solution, the choice of access technology (Wi-Fi or LTE) used to carry the voice/video call is transparent to both the user and the IMS, except for some minor differences in the way call termination and location-based services are handled.
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With Wi-Fi calling enabled smartphones, users can make calls using their regular operator telephony service at home even if they have poor cellular coverage. The
phone will utilize the Wi-Fi access point in the users’ homes and connect automatically to the operator provided voice service. Users can enjoy both voice and video calling. The solution is verified towards the smartphone brands that support Wi-Fi calling.
The operator benefit because they can reduce churn and attract new customers by: • Improving user satisfaction with enhanced voice and video calling coverage in users’ homes and in small enterprises over their own Wi-Fi access points.
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Providing attractive combined voice+data bundles and voice/roaming offerings and out-perform OTT voice services with ease-of-use and high quality voice services.
•
Cost-efficient deployment of extended voice coverage and fasttime-to-market:
•
More cost efficient to re-use existing Wi-Fi coverage than deploying costly Femto coverage
•
More cost efficient to support natively integrated Wi-Fi calling in the device and network. Reduces operator costs for developing and maintaining separate voice roaming apps.
•
Network efficiency with one core network for all services – Wi-Fi calling and VoLTE
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2
LTE BROADCAST LTE Broadcast can be used for file download and for streaming services, for example, mobile television. It is based on the 3GPP standardized Multimedia Broadcast and Multicast Service (MBMS). Evolved MBMS (eMBMS) is used to denominate the MBMS service in Evolved Packet Systems including E-UTRAN (LTE). LTE Broadcast is a point-to-multipoint service in which data is transmitted from a single source entity to multiple recipients. Both the air interface and the transport network use fewer resources even when a few devices are interested to receive the same data. When LTE Broadcast is active, up to 60% of the radio resources can be allocated for LTE Broadcast only. UEs in both idle and connected mode can receive the broadcasted services. UNICAST
BROADCAST
Brings advanced personalized services
Brings scalability and cost optimization
›One data channel per user
›One data channel per content
›Limited channels and limited number of users
›Limited data channels and unlimited number
›Any content, any time, anywhere
of users ›Popular services delivered in dense areas
Figure 4-13: Unicast vs Broadcast
Some of the LTE Broadcast use cases are shown in Figure 4-14. Premium Event Service
Deliver live premium contents in high dense areas
Media Services
Offer media services with efficient delivery & manageability
OTT Optimization
Provide additional value for OTT offerings
Data Offload
Relive network congestion by broadcasting contents
Complementing Emergency Services
Deliver updates and extra information during emergency situations
Figure 4-14: eMBMS Use Cases
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2.1
LTE Broadcast Network Architecture The eMBMS is realized in the 3GPP specifications by the addition of a number of new capabilities to existing functional entities of the 3GPP architecture as well as the addition of new functional entities.
Software upgrade New network element
OSS-RC/ENIQ-S
CONTENT SERVICE
M1
BMC
NBI
Uu
SG-mb
Sm
Live content
MBMS SGi-mb GW
MME
BDC
Highly capable devices: › Processing capability › Video quality › Content storing/caching
Satellite feeds
M3 eNB/ MCE
eNB/ MCE LTE RAN
M1 EPC BM-SC MBMS-GW MBMS MCE BDC BMC NBI
Live encoder Live feeds
File delivery
Content stores CDN feeds
Broadcast Multicast Service Center Multimedia Broadcast/Multicast Service Gateway Multimedia Broadcast/Multicast Service Multi-cell/multicast Coordination Entity Broadcast Delivery Center Broadcast Management Center North Bound Interface
Figure 4-15: End to end Solution
The Multicell/Multicast Coordinating Entity (MCE), defined as a logically separate node, is physically integrated into the Ericsson RBS. The main function of the MCE is as a protocol interface between the MBMS gateway (MBMS GW) and the logical node eNB. It also performs admission control and allocation of radio resources used by all eNodeBs in the MBSFN Area. Ericsson LTE RAN uses the distributed MCE architecture and it is implemented as a software upgrade of the eNodeB and the OSS. The optional feature Internal MCE, FAJ 121 3059, is handling the configuration and the M3 Connection handling towards the MME. The M3 connection is the control interface for eMBMS (evolved Multimedia Broadcast and Multicast Service) and is used by feature LTE Broadcast. The eNB/MCE uses Session Control Signaling (received from MME) to initiate configuration of radio resources to be used for broadcast transmissions. eNB joins the IP Multicast group in order to receive IP Multicast packets from MBMS GW. The BMC, Broadcast Management Center belongs logically to the core network and it is the node where the eMBMS services are configured.
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BM-SC, the Broadcast-Multicast Service Center, is known in Ericsson as BDC, Broadcast Delivery Center . It is the interface towards the content providers. This node handles eMBMS sessions (start, stop) and delivers user plane media to the MBMS-GW. The MBMS-GW handles the control signaling and user plan data for eMBMS. It provides functionality for broadcasting of MBMS IP Multicast packets to each eNB transmitting the service. The MME must be updated to handle eMBMS control signaling both towards eNodeB but also towards MBMS-GW. It provides Session control of MBMS bearers to the E-UTRAN access. It sends Session control messages towards multiple E-UTRAN nodes eNB/MCE.
2.2
Services and MBSFN principle Every time a new service is configured in the BMC, it is mapped to a broadcast area, which is a logical group of service areas. A service area is the smallest area that can be used for a single LTE broadcast transmission by the BDC. Depending on the network planning, one service area covers one or several LTE cells. Service areas are defined by their SAI (Service Area ID). Services Broadcast Area
Service Area 1
Service Area 2
•
Service Bearer (TMGI)
•
Mapped to a BA
•
Mapped to 1 or more SA
Service Area 3
MBSFNArea 1
MBSFNArea 2
MBSFNArea 4
MBSFNArea 3
MBSFNArea 5
Requires GPS or 1588 V2 time/phase synch
› Transmission of identical waveforms at the same time from multiple cells within an MBMS Single Frequency Network (MBSFN) › An MBSFN transmission from multiple cells within an MBSFN area is seen as a single transmission by a UE, i.e the Ue combines the signals from multiple cells in the cells’ border › MBSFN reception is possible both in connected mode and in idle mode
Figure 4-16: eMBMS Areas and Services
A service area consists of one or more MBSFN Areas. MBSFN stands for MBMS Single Frequency Networks. In E-UTRAN, MBMS is provided with single frequency network mode of operation. This means that multiple cells, that belong to the same MBSFN Area, transmit identical waveforms at the same time at the same frequency. This is seen by the UE as a single transmission.
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Therefore the definition of an MBSFN Area is a group of cells within an MBSFN Synchronization Area of a network, which are co-ordinated to achieve an MBSFN Transmission. Except for the MBSFN Area Reserved Cells (which do not broadcast the services), all cells within an MBSFN Area contribute to the MBSFN Transmission and advertise the services that are broadcasted. The UE may only need to consider a subset of the MBSFN areas that are configured, i.e. when it knows which MBSFN area applies for the service(s) it is interested to receive. When a service of interest is broadcasted, the UE reads system information to find information in which subframes the specific MBMS session is broadcasted. This can be considered a macro diversity gain as show in Figure 416.
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3
LOCATION SERVICES In today’s market, the demand for mobile location is growing, both from consumers as well as from authorities. Location is a vital component in consumer services like social media, search, advertising and navigation. For authorities, mobile location is mandatory for emergency-call location, and can also be used for road-traffic management and machine-to-machine (M2M) purposes. To be able to support this growing market demand, Ericsson offers a flexible positioning platform, Ericsson’s Mobile Positioning System (MPS), which can handle both consumer and governmental needs for 2G, 3G and LTE. It uses defined and secure interfaces, and provides business model flexibility while protecting the network from abuse and overload. The Mobile Positioning System also provides cost-effective utilization of system resources and applications by serving several mobile networks simultaneously. The Mobile Positioning System can be used for a wide array of consumerdemand services like search, mapping and navigation. As part of the end-to-end Location Based Services solution, it can also be used for road-traffic management and emergency-call positioning, as well as new market opportunities like location-based advertising. EPS
Beacons IMS
HSS HLR
LCS App Lh/SLh
EPC Ml ENB
WCDMA Beaco ns
MSC
SGSN
Emergency app
Middle Ware
SLg
GMLC/SLP
External GMPC/SLP
Lr
Lg
SLs
RNC
E-SMLC
CDR
Iupc
GSM
SAS Beaco ns
MSC
Billing System
Lr
SGSN Lb BSC
SMLC
O&M (Alarm, Statistics Bulk CM etc)
OSS/NMS
Figure 4-17: Ericsson Mobile positioning System
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The positioning methods supported by LTE are listed in the figure below.
› CELL-ID (CID) › CELL-ID + Timing Advance (ECID) › Observed Time Difference Of Arrival (OTDOA) › Assisted Global Positioning System (A-GPS)
Figure 4-18: Positioning Methods for LTE
Details about the Ericsson Mobile Positioning Systems are explained in the Mobile Positioning Systems Overview course. An overview of the positioning methods can be found at the appendix.
3.1
Gateway Mobile Positioning Center (GMPC) Functional Overview As illustrated in Figure 4-17, the GMPC is an important node in Ericsson Mobile Positioning System, and it acts as the gateway between the clients of the Location Services (LCSs), that is, the middleware or applications, and the network providing the locations. Gateway Mobile Location Centre (GMLC) and Secure user plane Location Platform (SLP) are nodes described in technical standards for LCS in GSM, UMTS and EPS by 3GPP and Open Mobile Alliance (OMA). For EPS, the related radio subsystem is Long Term Evolution (LTE) FDD or TDD network. The GMPC is Ericsson implementation of a combined GMLC and SLP. For IP Multimedia Subsystem (IMS) network, the GMPC is also Ericsson implementation of Location Retrieval Function (LRF) and Routing Determination Function (RDF), as specified by 3GPP. The GMPC supports call routing to a correct emergency center, as well as the provisioning of the location information to the same emergency center. The GMPC allows authorized applications to locate mobile subscribers using a variety of positioning methods, and the GMPC can handle connections from multiple LCS Clients simultaneously.
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The GMPC offers an XML/HTTPS based interface that LCS Clients use to communicate with the GMPC. The communication consists of location requests from LCS Clients and location answers from the GMPC. The GMPC has the ability to do the following:
3.2
•
Determine the location of an MS or User Equipment (UE) and respond to the LCS Client
•
Push the location of an MS or UE on the request of a subscriber, to an LCS Client
•
Monitor positioning related criteria defined by LCS Clients, and to report to the LCS Clients when the criteria are fulfilled
Serving Mobile Positioning Center (SMPC) Functional Overview The SMPC is Ericsson implementation of SMLC, Stand-Alone SMLC (SAS), and Evolved Serving Mobile Location Center (E-SMLC) in consolidation to support the location services in the Access Networks of GSM™-EDGE , GERAN, UTRAN and E-UTRAN. The SMPC determines the locations of User Equipment (UE) and exchanges the location information with the core networks. In the GERAN, SMLC provides functions required to support LoCation Services (LCS), defined by 3GPP. In the UTRAN, the SAS provides functions to support LCS in SAS centric mode. In the E- UTRAN, the E-SMLC provides functions to support LCS in Long Term Evolution (LTE) FDD or TDD network. To get positioning to work in the network, not only an SMPC is needed, but also network features in different access. For LTE, special features must be activated in the HSS, MME and eNB. A GMLC is required to report the positioning to LCS Client or applications requesting this information. For LTE, the evolution of the SMPC Node is the E-SMLC.
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4
SUMMARY The students should now be able to: 4 4.1 4.2 4.3
Describe key LTE Solutions Explain the options for Voice; CS Fallback, VoLTE and Wi-Fi calling Describe the LTE Broadcast Service, eMBMS Explain Location services in LTE
Figure 4-19: Summary of Chapter 4
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Intentionally Blank
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5 LTE Mobility
Objectives On completion of this chapter the students will be able to: 5 5. 1 5.2 5.3
Explain the various LTE mobility scenarios Describe LTE idle mode mobility Detail Intra LTE connected mode mobility; handovers and session continuity Explain IRAT Handover scenarios
Figure 5-1: Objectives of Chapter 5
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1
INTRODUCTION As a LTE UE moves through the network in idle mode it performs cell reselection between LTE cells on the same or different frequencies and other Radio Access Technologies (WCDMA, GSM or CDMA2000) based on the capability of the UE and the System Information broadcast from the LTE Cell. This system information is divided up into System Information Blocks (SIBs) with SIB 3 carrying cell reselection parameters common to all neighbors (same/different frequency and IRAT and the neighbor cell details in SIBs 4, 5, 6, 7 and 8 as illustrated in Figure 5-2 below. For connected UEs intra-eNodeB handover is used between cells in the same eNodeB and either X2 or S1 Handover between cells in other eNodeBs as illustrated in Figure 5-2 below. System Information SIB 3: Common reselection info SIB 4: LTE same frequency SIB 5: LTE different frequency SIB 6: WCDMA SIB 7: GSM SIB 8: CDMA2000
LTE f1 Intra-eNodeB Handover
X2 or S1 Handover Inter-Frequency Session Continuity, Coverage-Triggered Or Inter-Frequency Handover, Coverage-Triggered
LTE f2
WCDMA Session Continuity, Coverage-Triggered Or WCDMA IRAT Handover, Coverage-Triggered
WCDMA
GERAN CDMA2000 Session Continuity, Session Continuity, Coverage Triggered Coverage-Triggered
GSM
CDMA2000
Figure 5-2: LTE Mobility Introduction
When poor coverage is detected on this LTE frequency the session may be continued on another LTE frequency, WCDMA, GSM or CDMA2000 using the relevant ‘Session Continuity, Coverage Triggered’ optional feature. In all ‘Session Continuity’ features no measurements are required on the target frequency or Radio Access Technology (RAT) to perform the handover. For LTE inter-frequency and WCDMA the performance of ‘Session Continuity’ may be improved using the ‘Inter-Frequency Handover’ or ‘WCDMA IRAT Handover, Coverage-Triggered’ optional features. With these features it is possible to get measurements from the other frequency or RAT and perform the handover only when the other frequency or RAT meets a defined minimum level.
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2
IDLE MODE MOBILITY A UE’s mobility is handled by making use of so called Tracking Areas and cell reselection. This cell reselection can occur Intra LTE, Inter LTE or Inter RAT. The UE will determine parameters for cell selection and reselection from reading the broadcasted system information from the eNb. The UE will use these parameters to determine whether a PLMN or cell is suitable for selection nd reselection. Thus, in idle mode the UE is responsible for its own mobility.
› Monitor Paging › Monitor System Information › PLMN Reselection LTE f1 › Cell Reselection › Location Registration (TA update) WCDMA
LTE f2
CDMA2000 GSM
Figure 5-3: UEs in Idle Mode
The only way to reach a UE in idle mode is to page it. For this reason, when it moves throughout the network, it is required to inform the network of its whereabouts using Tracking Area Updates. A number of tracking areas will be configured in the MME and each tracking area will contain a number of cells. Each cell in a given tracking area will include the Tracking Area Code (which TA it belongs to) in its broadcast information. During the attach procedure, the MME will have sent a tracking area list to the UE with a number of tracking areas included. Using this list, the MME will be aware of the whereabouts of the UE to the granularity of a number of tracking areas which the MME will use to page the UE should the need arise.
2.1
Periodic TAU An example of when a TAU should be performed is a Periodic TAU. This is shown in Figure 5-4. This will occur in the case where a UE has not performed a normal TAU and has not moved from IDLE to CONNECTED before a timer has expired. This timer is sent to the UE during the attach procedure. Every time a TAU is performed this timer is restarted. It is also restarted when a UE moves from CONNECTED to IDLE and is a configurable parameter. Periodic TAU is used to locate the UE to avoid unnecessary paging attempts for a UE that has lost coverage and is not able to inform the MME that it is inactive.
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UE moves to connected mode
UE in idle mode
Timer
TA Update
Timer
TA Update
UE moves to idle mode
Timer
TA Update
Figure 5-4: Periodic Tracking area update
TAUs are also sent during the attach and detach procedures.
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LTE Mobility
3
CONNECTED MODE MOBILITY When a UE gets in connected mode it will be configured with specific measurement criteria. The eNB will send the measurement configuration, by which it will order the UE to measure on the Reference Signal Received Power (RSRP) and Reference Signal Received Power (RSRQ) and compare the serving cell measurement against any detected neighbors. Based on these measurements and the mobility parameters configured by the operator in the eNB, the UE may decide to send a measurement report. UE measures on serving cell and scans all neighboring intra-LTE cells (504 PCIs) -> No UE neighbor list for intra-LTE -> Detected ”good” cells are reported -> IRAT cell lists are used
HO?
Best Cell Evaluation
eNB makes HO decision based on UE measurements
Event?
Serving cell
Neighboring cell
Figure 5-5: Connected mode mobility
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The eNB configures the UE to send a measurement report based on the (mobility related) events, for example a neighbor cell that has stronger signal quality than the current serving cell or poor coverage in the current serving cell.
UE measures on cells and reports only when event criteria are met Figure 5-6: Event Triggered Measurement Reporting
The Intra-E-UTRAN-Access Mobility Support for UEs in ECM-CONNECTED handles all necessary steps for relocation/handover procedures, like processes that precede the final HO decision on the source network side (control and evaluation of UE and eNB measurements taking into account certain UE specific area restrictions), preparation of resources on the target network side, commanding the UE to the new radio resources and finally releasing resources on the (old) source network side. It contains mechanisms to transfer context data between evolved nodes, and to update node relations on C-plane and U-plane. There are several types of mobility for the UEs that are in RRC_Connected mode as listed in Figure 5-7. › Intra LTE Intra-frequency Handover - Intra RBS Handover - X2 based Inter RBS Handover - S1 based Inter RBS Handover › Coverage Triggered Session Continuity to -WCDMA -GERAN -CDMA -different LTE frequency › Coverage triggered Handover - Inter-frequency (Intra RBS, X2 or S1 HO) - WCDMA IRAT - Intra-LTE Inter-mode Handover (X2 or S1 HO) › CS Fallback to GERAN / UTRAN / 1xRTT CDMA2000 › SRVCC Handover to UTRAN/GERAN Figure 5-7: Mobility in RRC_CONNECTED mode
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3.1
Intra LTE Intra Frequency Handover When a UE detects that one or several neighbor cells have become better than the serving cell by a defined offset the UE will send the measurement report containing this event as illustrated in Figure 5-8 below.
Cell A (F1) Measurement RSRP / RSRQ Serving Cell (B) Serving Cell (A)
Cell B (F1)
Neighbour Cell (B)
Neighbour Cell (A) Time
Figure 5-8: Intra-Freq. LTE Handover
Once the eNodeB receives the event from the UE it will perform the handover using one of the Intra-LTE handover procedures listed below: 1. The intra-eNodeB handover procedure is used when both the source and target cells reside in the same eNodeB. 2. The X2 inter-eNodeB handover is primarily used when an X2 relation exists between source and target eNodeB. Both source and target eNodeB must be connected to the same MME. 3. The S1 inter-eNodeB handover is primarily used when no X2 relation exists between source and target. Source and target eNodeB can be connected to the same or different MME. The UE will continue to send the event until the handover is completed or the event is no longer valid.
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3.1.1
Intra-LTE Handover Types The Intra-LTE Handover procedures are illustrated in Figure 5-9 below.
S-GW
S-GW
MME in Pool
MME in Pool MME
MME
MME
MME
MME
S1 CP S1 UP X2 CP and UP
S-GW
S1 Handover
X2 Handover Intra-eNodeB Figure 5-9: Intra-LTE Handovers
An X2 handover is a handover that occurs over the X2 interface in the EUTRAN. This type of handover will always be intra LTE and will always involve the UE moving between eNbs in the same MME pool area, shown above in Figure 5-9. The X2 handover will entail communication between a source eNb and a target eNb to prepare a target cell (which will be indicated by the UE in the measurement report) for the admission of an additional user to that cell. The X2 interface can be set up manually via OSS-RC or via the ANR function (see Chapter 6 for ANR) if activated. In cases when the UE moves between eNB’s that belong to different pooling areas the handover procedure necessarily has to be executed via the S1 interface. This can also be seen in Figure 5-9. In such cases at least the MME function, holding the UE context has to be relocated from one MME node in the first pool to another MME node in the second pool.
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3.2
Poor Coverage Handling When a UE detects that the LTE coverage has dropped below a defined threshold the UE will send the measurement report containing this event as illustrated in the figure below. › Coverage Triggered Session Continuity to -WCDMA -GERAN -CDMA -different LTE frequency
Cell A (LTE F1)
› Coverage triggered Handover Cell B (LTE F2 or other RAT) Measurement RSRP / RSRQ Serving Cell
- Inter-frequency (Intra RBS, X2 or S1 HO) - WCDMA IRAT - Intra-LTE Inter-mode Handover (X2 or S1 HO)
UE sends report
Time
Figure 5-10: Poor Coverage Handling
The event can base its triggering criterion on either RSRP or RSRQ as illustrated in the figure above. Once the UE begins sending reports then it will continue to do so at regular intervals until a time when the event no longer exists. For example, handover has taken place to another frequency or to a cell on another RAT or a situation where the coverage in the cell returned to an acceptable value. Once poor coverage on LTE is detected steps are taken by the Network to move the call to LTE on another frequency or to another access technology (WCDMA, GSM or CDMA2000) using either ‘Session Continuity’, ‘Inter-Frequency Handover’ or ‘WCDMA IRAT Handover’.
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3.2.1
Session Continuity, Inter-Frequency and IRAT Handover The Inter-Frequency, WCDMA, GERAN and CDMA2000 Session Continuity Coverage-Triggered optional features provide the basic active mode mobility between frequencies in the LTE network and other RATs. When these features are active, the UE can be directed to transfer between frequencies in the LTE network or other RATs while maintaining the data session when poor coverage is detected. When these features are not used the UE is not configured to report the poor coverage event and will remain connected to the original frequency within the LTE network with poor LTE coverage. If the UE is eventually released, it is required to perform idle mode cell reselection to move to another LTE frequency or IRAT. This interruption time may be long since the UE may be connected to the LTE frequency with poor coverage for a long period while the alternative LTE frequency or IRAT is capable of providing better quality. Session Continuity uses a process called ‘release with redirect’ where the UE is released on LTE and given the frequency of the other LTE cell or IRAT neighbor where it will setup a new connection and continue the data session. The interfrequency and WCDMA IRAT handover features on the other hand move the UE from connected mode on LTE to connected mode on the other frequency or WCDMA cell. › Release with Redirect (Coverage Triggered Session Continuity) RRC-CONNECTED
› Handover
Bad coverage detection triggers Release with Redirect: Redirect Information Frequency
RRC-IDLE ”RRC-CONNECTED”
CellReselection according to redirect information (GSM, WCDMA, eHRPD, LTE IF)
RRC-CONNECTED Handover Command Move to reserved resources
”RRC-CONNECTED”
Figure 5-11: IF / IRAT Mobility
The purpose of the Inter-Frequency and WCDMA IRAT handover Coverage Triggered optional features is to extend Session Continuity with the option of initiating a handover to a cell belonging to another frequency or RAT instead of initiating a release with redirect. In this case the UE will not enter the RRC_IDLE state. The fact that the UE will not enter the idle state means that session transition to and from LTE on another carrier or WCDMA is possible with reduced interruptions to data flows during the transition process.
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3.2.2
LTE and Wi-Fi Mobility IMS & VoLTE
Cellular coverage eNB
EPC WMG /ePDG
Any ISP Secure tunnel (IPsec) SIM authentication
Complete solution with Ericsson EPC, IMS and RAN Figure 5-12: Seamless mobility between LTE and Wi-Fi
With Wi-Fi calling enabled smartphones, users can make calls using their regular operator telephony service at home even if they have poor cellular coverage. The
phone will utilize the Wi-Fi access point in the users’ homes and connect automatically to the operator provided voice service. Users can enjoy both voice and video calling. The solution is verified towards the smartphone brands that support Wi-Fi calling.
The operator benefit because they can reduce churn and attract new customers by: • Improving user satisfaction with enhanced voice and video calling coverage in users’ homes and in small enterprises over their own Wi-Fi access points.
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Providing attractive combined voice+data bundles and voice/roaming offerings and out-perform OTT voice services with ease-of-use and high quality voice services.
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Cost-efficient deployment of extended voice coverage and fasttime-to-market:
•
More cost efficient to re-use existing Wi-Fi coverage than deploying costly Femto coverage
•
More cost efficient to support natively integrated Wi-Fi calling in the device and network. Reduces operator costs for developing and maintaining separate voice roaming apps.
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Network efficiency with one core network for all services – Wi-Fi calling and VoLTE
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4
SUMMARY The students should now be able to: 5 5. 1 5.2 5.3
Explain the various LTE mobility scenarios Describe LTE idle mode mobility Detail Intra LTE connected mode mobility; handovers and session continuity Explain IRAT Handover scenarios
Figure 5-13: Summary of Chapter 5
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6 Operation and Maintenance in LTE RAN
Objectives On completion of this chapter the students will be able to: f
6. Describe O&M (Operation and Maintenance) for EPS 6.1 Describe OSS-RC 6.2 Describe ENM 6.3 Explain the concepts related to Smart Simplicity and Self-Organizing Networks (SON) Figure 6-1: Objectives of Chapter 6
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1
OVERVIEW To manage the LTE radio access network, powerful but simple to use user interfaces are needed. The user-interfaces should be able to manage the network elements (e.g. eNodeB) completely. However, for an operator, it should also be possible to manage multiple nodes at the same time. The Mobile OSS (Operation and Support System) product portfolio is preintegrated for Ericsson mobile (GSM / WCDMA / EPS), IMS and Service networks, putting the operator in command of both services and network infrastructure.
The Mobile OSS portfolio contains the following main products: › Operations Support System for Radio and Core (OSS-RC) (EPS Support included since Release 10) › Ericsson Network Manager (ENM) › Ericsson Network IQ (ENIQ) › Element Management tools Figure 6-2: Ericsson Mobile OSS Portfolio
As pointed in the figure above, the primary tools used include: Operations and Support System, Radio and Core (OSS-RC): With over 950 systems deployed with over 500 operators worldwide, OSS-RC is the market leader in Mobile network domain management (also referred to as the “sub-network manager”). It has support for many types of network/ elements, including: GSM, WCDMA, LTE, RBS 6000, AIR, HLR, MSC, CUDB, SGSN, CGSN, GGSN, SASN, MGW, SAPC, CPG, MINI-LINK, IP Router, SDP, IMS, IMT. Ericsson Network Manager (ENM): The Ericsson Network Manager will ultimately provide a complete end-to-end management solution for GSM, WCDMA, LTE radio network, core network, Wi-Fi, and the IP & transport network. Ericsson Network Manager will be the unified network management system for multi technology, multi domain, as well as providing multi-vendor support through systems integration. The first two releases of the ENM are in 2015.
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Ericsson Network IQ (ENIQ): Ericsson Network IQ (ENIQ) is able to provide the Network Operation Center and Engineering department with reports around the Network Resource usage and status. By correlating network resource usage data with individual system services it will be possible to improve the operating margin due to higher utilization of available resources, and better capacity planning. Complex ad-hoc queries can be carried out in seconds without data explosion or collapsed data loading seen in performance management system based on traditional databases. Element Management tools: Element Management tools focus only on one network element, unlike the other tools mentioned above. Depending on the type of the node there could be a graphical user interface (e.g. Element Manager GUI) and/or a command linebased interface (CLI or COLI). Besides these four tools, there are other tools that help smoothen the running of the network.
•
SON Policy Manager: operators set policies that dynamically steer automatic network behavior of their multi-technology, multivendor networks
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SON Visualization: provides clear and simple geolocation of data and the ability to correlate multiple datasets, allowing operators to be in control of their operations.
•
SON Optimization Manager: a multi-vendor, multi-technology product for the continuous optimization of mobile networks
These tools, together with the Ericsson Network IQ and ENM are specifically designed for multi-vendor and multi-technology integration.
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Figure 6-3 and Figure 6-4 below show the changing scenario in network management paradigm.
Network Management Fault Management
Performance Management
Inventory Management
Domain Management
Domain Management
...
SON Applications
OSS-RC
Domain Management
Domain Management
Routers
LTE RAN, EPC
Figure 6-3: Today’s Management Network
The management networks today are domain management focused. OSS-RC is a good example. It leads to Data fragmentation, Complex integration, Duplication of functions, Multiple suppliers and Inefficient use of IT resources. To streamline the Network Management, Ericsson has introduced Ericsson Network Manager (ENM). It is a new platform that solves the problem of scale to let us handle all network technologies through the same management platform. From the different radio access technologies, through Wi-Fi, microwave, optical, Ethernet to IP, circuit and packet core and IMS and VOLTE. It’s one contiguous network with one manager that can be used to manage the full scope – not just as a domain manager but as a network manager, with built in capabilities for multilayer network service management. And it will even handle the new technologies coming through – like virtualized nodes, and SDN controllers. It uses a data centric architecture that allows for a unification of information. Applications that would have been buried in a single domain are lifted up to be instead true network management applications. Here with access to a broader range of information we can build better and smarter functions. Not only can applications see a wide range of domains, but information from one part can support better decision making in another – traffic utilization information from performance management can be used for instance as an input for energy management.
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Data mediation is provided out of the box for Ericsson’s full range of network equipment, with a flexible new framework to support integration to third party network domains that supports multi-vendor applications. North bound interfacing is also eased with well-defined NBIs providing secure access to data from the full network. Combined with pre-integration to Ericsson OSS solutions this takes the traditional ‘need to have’ domain manager and makes it a ‘want to have’ component into the larger OSS process environment. All of this runs on a scalable platform that will run on the server systems we are currently rolling out to our customers, and that will be available in a fully virtual environment. ENM Standard NBIs
Ericsson OSS Solutions
Expert Diagnostics
Ericsson Domain Mediation
E2E Performance Reporting
Incident Management
Workflow Manager
Network Optimization
SON Orchestration
UNIFIED DATA
…
MV mediation
Figure 6-4: Future Management Network
Ericsson Network Manager is available from September, 2015. Figure 6-5: Mul Interface below shows the Mul (and the S1-/X2-interfaces) between the eNodeB and the Network Management products- namely the OSSRC and the ENM.
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It is an IP based interface supporting a wide range of protocols to allow remote management of the eNodeB once integration is completed.
› eNodeB – OSS-RC / ENM interface – The Mul Interface is used to manage the eNodeB and the radio network functions supported by the eNodeB Core Network OSS-RC / ENM
S1
S1
X2 eNode B
S1
Mul
X2
eNode B
eNode B
Figure 6-5: Mul Interface
› Performance Management › Software Management › Network Inventory › Fault Management › Configuration Management Figure 6-6: O&M Areas
Through the Mul interface, the user can perform
•
Performance management: o initiation of measurements/recordings o collection of statistics and traces
•
Software management: o software deployment (remotely and in parallel) o centralized node backup administration
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o license management •
Central network inventory functions o hardware and software o license inventory
•
Fault management support: o Alarms and events notification o Logs transfer
•
Configuration support: o auto-provisioning of new nodes o planned configuration o SON support
The details of these operational areas are provided later in the chapter. The Mun interface uses a similar protocol stack as Mul. It supports Integration Reference Point (IRP) interface specifications from 3GPP.
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2
O&M ARCHITECTURE IN LTE RAN The O&M solution for LTE is implemented in RBS and OSS-RC (or the ENM). An operator might have different types of RBSs in its network (as explained in Chapter 3), and depending on the type, on the RBS level, there are some differences in the O&M environment. For example:
•
All the RBSs with the DUL20, DUS32, DUS41 and the micro RBSs (RBS 6501) have one way of working. These are referred to as the “Gen1 RBS”. These RBSs are based on CORBA/IIOP over the Mul interface.
•
All the RBSs that have Baseband 52xx have another way of working. These are sometimes referred to as the “Gen2 RBS”. The O&M is based on the new NetConf / COM-CLI interface and is a part of Ericsson’s Component Based Architecture (CBA)
The pico RBSs (RBS 6402) work slightly differently from an O&M point of view, as it is meant to be deployed in unsecure environments. Pico resembles the Gen 2 RBS from an O&M point of view.
2.1
OSS-RC and ENM Both OSS-RC and ENM are domain management and network management OSS systems respectively, which may be used to manage the LTE radio access network. The primary GUIs are shown in the two figures below:
Figure 6-7: OSS-RC: OSS Explorer
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The Ericsson Network Manager (ENM) is presented below.
Figure 6-8: Ericsson Network Manager (ENM): OSS Applications
The ENM is a new management solution from Ericsson. In this chapter, all the examples are shown with OSS-RC. The summary of the applications and functions of the OSS-RC are made together with the different O&M areas later in the chapter.
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2.2
G1 RBS (Macro, micro) O&M architecture Besides the OSS-RC and the ENM, it is possible to manage the RBSs with its Element Management interfaces. There are namely two interfaces- the Element Manager GUI as shown in the figure below and the Command Line Interface (COLI).
Figure 6-9: Element Manager GUI
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2.3
Pico RBS (RBS 6402) O&M architecture Pico RBS, a solution to implement the small cell deployments, is different (O&M wise) than the G1 RBS for two reasons:
•
It has a different O&M architecture based on COMCLI/CBA
•
It is meant to be deployed in unsecure environment, and in large numbers Pico RBS
› Public network › Physically exposed
MME
Attack
› Large numbers
Untrusted Network
SGW Security GW
Intruder
OSS
Trusted Network
RNC
Figure 6-10: Pico (and Micro) RBS environment
Because of the unsecure environment/network the pico (and micro) RBSs could be deployed in, IPsec may be used between the RBS and the security gateway. For the pico RBS, a very simplified Integration GUI is provided at the site to initiate auto-integration. However, once the integration is completed, there is no possibility to connect to the pico RBS locally. Of course, operations and management of the pico RBS is possible from the OSS-RC or ENM. From the OSS-RC or ENM, one may use the command line interface (with ssh/sftp) to manage the node. There is no GUI in the pico RBS. The command line access (and operations) are similar to the G2 COLI (=COM-CLI) access.
2.4
G2 RBS (Baseband 52xx) O&M architecture Just like the pico RBS, the G2 RBS also has an O&M architecture based on COMCLI/CBA. However, it has a more elaborate set of O&M functions compared to the pico RBS. It is possible to use either the command line interface or the graphical user interface (GUI) to manage a G2 RBS.
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3
OPERATION AND MAINTENANCE (O&M) AREAS In the following sections, a more detailed explanation of the Operation and Maintenance areas is given. Although the new Ericsson Network Manager (ENM) may also be used as the management tool, the OSS-RC is explained here.
3.1
Configuration Management Basic principles for configuring LTE are to prepare and store configuration data in OSS-RC and then distribute it to the RBSs over the network. OSS-RC provides an external interface for exchanging configuration data with external planning tools for radio network planning and transport network planning. Configuration data is refined and loaded to RBSs with the assistance of OSS-RC. Performance data collected by OSS-RC can be used as input for network evaluation, further planning, and optimization. The primary/basic applications used for working with configuration include:
› The “Bulk Configuration Management “ interface in OSS-RC › Base Station Integration Manager (BSIM) in OSS-RC › Graphical user interface (GUIs) for data entry /checks in OSS-RC › Element management applications and command line interface directly into RBSs Figure 6-11: Configuration Management
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•
The bulk CM interface in OSS-RC is used for radio network and transport network configuration data import and export functions. Multiple nodes may be chosen making management efficient while making changes across the network. The configuration data is prepared externally, transferred to OSSRC and imported to a planned area, before activating it.
•
BSIM in OSS-RC is a prerequisite for auto-integration and interworks with several applications in the OSS-RC and other servers to rollout new nodes efficiently.
•
Basic applications in OSS-RC with associated graphical user interfaces provide possibility to check or make data changes. The “Common Explorer”, “Cabinet Viewer” and “Network Status Display” are examples of such applications.
•
Element management applications and command line interface to enter data directly into RBSs
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OSS-RC provides both graphical user interfaces and a machine interface for working with the configuration of the radio and transport networks. The radio and transport changes can be made directly to the live network (the valid area – in the case of smaller changes) or the changes are made to a planned area before they are implemented in the live network (for larger changes). The planned area can be consistency checked before the changes are applied. It is also possible to make a fall back area of the configuration e.g. before a larger change is implemented for security reasons. Several fallback areas can be saved and the operator can choose what area to fall back to if needed. It is possible to exchange all operator controlled radio network data with other systems using the import and export interface compliant to the Bulk CM IRP. The LTE RAN configuration support also includes a Transport Network Viewer. This tool enables the user to get easy access in a user-friendly format to both the logical and physical connections for the transport network. The viewer also enables the user to see the detailed configuration of each node. A parameter check function facilitates the monitoring of changes in the network. It can compare the current valid area with a target configuration and then present the differences. A Cell Availability function provides the possibility to monitor cell status on regular basis. The collected status information is displayed in a comprehensive overview consisting of both a summary of the status in the network and details for each cell that can be both sorted and filtered. Export File Editor (EFE) converts Bulk CM Export files to .xls format and .xls files into Bulk CM Import XML files. This makes it possible to have an off-line editing of configurations and an easy integration with off-line planning tools. CPP Scripting (CPS) is a text based tool that provides commands for viewing and manipulating the MOMs. It provides both comprehensive overview and detailed understanding of the status of MOMs. The Job Manager application in OSS-RC is used to download script or command file data to one or more nodes or node types, or to fetch data from the network. The job manager provides support for scheduling and progress checks of the jobs. Together with the Job Manager, OSS-RC provides pre-defined tasks (scripts) supporting key operator use cases. The tasks can be combined as a job, or run individually, towards one or multiple network nodes of the same or different node types. The application is thus common for all different kinds of nodes that OSS-RC supports. The Job Manager can also be used to create own jobs to complement the existing configuration applications. The Automated Neighbor Relations (ANR) eliminates the need for planning and optimization of LTE neighbors for handover. OSS-RC manages activation, deactivation and configuration of ANR for one or multiple eNBs. Any update to ANR function in the RBS (addition, deletion of neighbors with time stamp and other relevant data) is reported to OSS-RC and can be monitored in common explorer.
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LTE RAN Consistency Checker provides the operator with a safe and efficient way of verifying the consistency of parameter settings in the radio and transport network of the LTE RAN. Auto Provisioning is an efficient and error free planning and rollout process for new Radio Base Stations. The application Base Station Integration Manager (BSIM) ensures that each radio base station is configured correctly according to defined configuration and automates the integration of the radio base station into the network and shortens the site integration time as well as the overall provisioning duration. Automatic PCI Selection: Physical-layer Cell Identities (PCIs) are used in the LTE network as a way for User Equipment (UE) to distinguish between different cells. The numbers of PCIs are limited to 504 and therefore non-unique in the network. Thus, the same PCI must be used by several cells. The feature Automatic PCI selection in OSS-RC assigns PCIs in such a way that PCI values reused with minimum risk for collision. Automatic PCI Collision Resolution: As an evolution of the Automatic PCI Selection functionality, this feature builds on the formerly manual process to offer the operator maximum flexibility in order to maintain an optimized PCI plan in the network. This feature allows the operator to optionally find and resolve any PCI conflicts immediately, or schedule a resolution at another (configurable) time. LTE-WCDMA Mobility Support: This feature provides support in CM applications in OSS-RC to manage the handover and mobility options for LTE>WCDMA handover. Configuration Profile – LTE: Configuration Profiles provides an easy way set and maintain consistent configuration data across the entire network. Configuration Profiles is operational for all technologies supported by Common Explorer. Undo Plan – LTE: Undo Plan feature provides an easy way to undo specific configuration changes without affecting any other configuration changes to the network added for other reasons in parallel or after the configuration change in question. Undo Plan feature supports the automatic creation of an additional plan that can be activated to undo configuration changes activated by an ordinary plan. Network Status Display (NSD) provides a comprehensive and at the same time customizable display of the LTE RAN status. It makes it possible to from the same application conduct all necessary analysis for determining the cause for problems in
3.2
Fault Management The purpose of Ericsson’s fault management solution is to help the operator to manage faults in the complete mobile network in a cost efficient way. The solution is multi-vendor and multi-technology and provides full functionality including advanced expert system capabilities.
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The main function of the fault management solution in OSS-RC is to collect, preprocess, store, alert, view and forward alarms from the network. Graphical user interfaces provides flexible viewing of the alarms. The alarm status matrix provides an overview of the alarm situation, the alarm list viewer lists alarms and alarm information for one or several nodes, and the alarm log browser makes it possible to find and retrieve stored alarms of a certain type e.g. It is also possible to view the alarm symbols on a geographical map. Fault Management in OSS-RC handles all alarm action requests towards a supervised object. Typical actions are to turn supervision on or off, synchronize alarm lists with the network element, acknowledge alarms and search the alarm log. When an alarm is received in OSS-RC, the alarm severity can be changed or alarm information (like proposed repair actions) may be added before the alarms are stored. It is also possible to generate alarms based on statistics from the nodes (requires storage of statistics in OSS-RC statistical database) thus enabling supervision of negative statistical trends for example. The expert tool for fault management (FMX-II) together with Ericsson predefined or operator-defined rule packages allows the operator to focus on the real service affecting problems, as it enables powerful filtering and automation of routine tasks. The rules can for example discriminate certain types of alarms under certain circumstances. In some cases, the whole process from alarm detection to clearance can be automatically performed. Using FMX-II rules can reduce the amount of alarms with up to 70 % and is thus a powerful way of lowering cost of operations. Ericsson provides pre-defined rule packages for core network and for RAN. Alarms can be received from all types of network elements supporting SNMP, CORBA Alarm IRP, BNSI or ASCII interfaces. Alarm adaptation units exist of the shelf for a large range of network elements: all Ericsson’s standard nodes as well as Datacom and IT equipment as routers and LAN switches. Other network elements can easily be integrated as a customer service. OSS-RC Fault Management also supports mediation of the alarms to an external management system via either the proprietary BNSI interface or the standardized 3GPP CORBA Alarm IRP.
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Since OSS-RC 14A.1, a new northbound interface, SNMP Alarm NBI, was provided enabling OSS-RC to be integrated with NMS systems for alarm collection over SNMP interface. NMS
NMS
Network Manager
Alarm Notification
Event Notification
Filtering OSS-RC
FM Application Subnetwork Manager
RAN Alarm & FM event Log
RAN Alarm & FM Event List
Event Notification
Alarm Notification
NE
Alarm Handling
Element Manager
NE Alarm List
Internal Alarm Notification
NE Alarm Log
Event Handling
Internal Alarm Notification
External Alarms
NE FM Event Log
NE Availability Log
Internal Event Notification
Fault Handling
Figure 6-12: Fault Management Functionality
Fault management provides integrated alarm and event handling, using the functions as follows:
•
Fault Handling Fault handling in the RBS is performed close to the fault cause location. This function monitors the system for faults, performs automatic recovery actions for detected faults, and sends internal fault indications. For faults it cannot automatically recover from an alarm is issued, that is, manual intervention by an operator is required. The fault handling function uses state handling to indicate the current condition and availability of a resource.
•
Alarm Handling This function filters detected faults in the RBS and issues alarms. It maintains an alarm list with active alarms, distributes the alarms, and logs the alarm history. External alarm ports in the RBS receive signals from external detectors for various site equipment.
•
Event Handling This function handles fault management events. It distributes the FM events and logs the FM event history. Fault management generates events for things considered significant
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enough to be presented for a user, but not severe enough to be alarms. Events are stateless notifications unlike alarms, which are active until they cease. FM events are not supported in the current release of pico RBSs. •
Test Functions In addition to the automatic supervision of functions for monitoring the RBS, the operator can request manual tests to verify specific functions.
3.3
Security Management Security management functions support the following activities:
› Administration of O&M user accounts, roles, and profiles › Configuration of password policies and security audit logging › Configuration of filtering in the transport network › IPsec management › Virtual private network management › Public Key Infrastructure (PKI) certificate lifecycle management Figure 6-13: Security Management
Only legitimate users with authenticated access rights are authorized to manage the security-related functions and attributes. Security management tasks are described in the OSS-RC document Security System Administration, OSS-RC.
3.4
Software Management Software management functions support the following activities: • Software installation - transferring and loading an upgrade package from a file server to a network element file system •
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•
Software backup administration - backing up and restoring configurations including file management
› Configuration Backup • Creation • Transfer • Restoration › Upgrade Package Management • Install • Upgrade • Confirm › License Management • Install license Figure 6-14: Software Management
An upgrade package is a collection of software that can contain both fault corrections and new functions for a network element. The upgrade package is not intended for an individual node, but for a type of node. Software deliveries are either classified as an update or an upgrade depending on software content with the following definitions: • An update is a product version (R-state) that is created to provide corrections in the maintenance flow: all correction deliveries between releases are by definition updates (emergency update, corrective update) •
An upgrade is a product or product version created to provide additional functions to a customer: a delivery that changes release level, for example from L14A to L14B is by definition an upgrade
In both cases the function used to update or upgrade the node is called software upgrade. Software backup administration is divided in: • Configuration backup - handling copies of configuration backups saved for a network element, either in the file system of the network element or on a remote file server
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•
Configuration restore - rollback and restart of configuration backups from the local disk or from a remote file server
•
Disk management - structuring of configuration backups and removal of old unnecessary upgrade packages and configuration versions
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License File Installation is required to be able to use optional features. Hardware activation codes (HWAC) are also implemented with the license file.
3.4.1.1
Network Inventory The network inventory solution enables a user to retrieve up to date hardware and software inventory information from nodes and present it in OSS-RC or export it to an external network management system for inventory. Since both software and hardware information is accessed within the same tool, it is easy to inspect both HW and SW levels in a node before performing an upgrade or a correction.
3.5
Performance Management The PM function provides data for the LTE contribution to end-user performance with respect to the aspects of accessibility, retainability, and integrity. PM also provides data for LTE performance with respect to mobility, utilization, and availability. Several PM applications gather and process performance data. This data can be used to monitor key performance indicators, optimize network performance, identify trends, and troubleshoot problems in the RBSs. The basic performance applications are performance statistics, UE trace, and cell trace. These applications have graphical user interfaces that are accessed using OSS-RC. Note: Pico RBS does not support UE Trace and Cell Trace.
NMS
FTP of Statistics and recordings in xml and binary format
SQL query of performance management database
OSS-RC
Performance Statistics Application
Cell Tracing Application
System or User Defined
Performance Statistics Application
eNodeB
UE Tracing Application
User Defined
User Defined
Performance Recording Application
eNodeB
eNodeB
eNodeB
eNodeB
Figure 6-15: Performance Management Applications
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3.5.1.1
Performance Statistics The performance statistics data is generated as result of live traffic and consists of a number of predefined radio and transport network counters. OSS-RC acts as a centralized point for the initiation and collection of performance data for the RBS. The RBSs provide a graphical user interface and also a machine-to-machine interface allowing OSS-RC to administer the statistics. The PM function allows the user to create subscription profiles and subscribe to performance monitoring, and to subscribe to performance recordings through a graphical user interface. As a result of the collection one statistic file is generated for each RBS. Collected data files remain in OSS-RC for a limited time. Key Performance Indicators (KPIs) and performance metrics are based on performance statistics counters. Real-Time KPIs in NSD is a troubleshooting tool with unique position for accessing real time performance data. This feature further contributes for allowing fast diagnosis of low performing and sick cells.
3.5.1.2
Performance Recording Performance recording applications are used to collect events and radio-related measurements applicable to either a specific UE or an RBS. Note: Pico RBS does not support PM recordings, UE Trace and Cell Trace. Types of performance recording applications supported in LTE include Cell Trace and UE Trace:
•
Cell Trace Cell Trace function is used to troubleshoot issues on a specific cell or RBS. It gives visibility of air interface quality and UE performance of all (or a selected percentage) of UE within these cells and RBSs. It allows for network optimization when a new RBS is deployed or a new feature or frequency is deployed within an existing RBS.
•
UE Trace The UE Trace function records important events and measurements for a selected UE, traveling through a network. Only one UE can be selected for recording for each UE trace, but up to 16 simultaneous UE trace recordings can run in parallel for one RBS. The network operator selects UE using
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the International Mobile Subscriber Identity (IMSI) or International Mobile Equipment Identity (IMEI) Both UE Trace recording and Cell Trace recording log events and radio environment measurements selected by the operator. The main difference between Cell Trace and UE Trace is the way UE are selected for recording. In UE Trace, it is the operator that determines the UE to record. In Cell Trace all UE, or a subset of UE (UE fraction) in a selected cell are recorded. In UE Trace, the recorded events are reported individually and written to separate files for each UE being recorded. The recording files are collected every Result Output Period (ROP) for the duration of the scheduled recording. A ROP is a period of 15-minutes recording. The RBS puts each event received into the Cell Trace file or the UE Trace file (depending on what is activated). The recording files are transferred and stored in the OSS-RC local file directory. The feature Trace Event Streaming offers continuous transfer of traces as an alternative to transfer of recording files when each ROP is completed. The feature allows streaming cell trace events over TCP and UE trace events over UDP to remote nodes. Internal and external events are available for recording performance.
3.5.1.3
PM- Initiated UE Measurements The PM-Initiated UE Measurements feature in the ERBS managed element type, permits the operator to order UE to perform specific measurements in addition to the normal traffic measurements. The feature is configured in a flexible way. The measurements and reporting are based on the following functions:
3.5.1.4
•
Cell trace recording
•
UE trace recording
•
Reference Signal Received Power (RSRP) reporting
•
Reference Signal Received Quality (RSRQ) reporting
ENIQ The Performance Management solution in Mobile OSS is supported by Ericsson Network IQ (ENIQ). ENIQ is a PM product available either as an option in the OSS-RC product family or stand-alone without connection to OSS-RC. It is positioned as Ericsson’s high-end PM product for radio and core networks. See ENIQ Product Description for more information.
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4
SON CONCEPTS
4.1
Introduction: Radio Access Networks (RANs), such as LTE have evolved from a relative simple voice based mobile network based on GSM to a complex network providing a multitude of end-user services. To have control has been synonymous with managing in detail, resulting in an increasing cost for Operation & Maintenance (O&M) of the RANs when the networks grow and traffic increases. It is impossible to micro manage every piece of this complex communication network. Therefore, manual intervention on sub networks such as RANs needs to be eliminated, or at least reduced to a minimum. It is therefore of the utmost importance that when introducing LTE, which will be a new sub network, the operational impact is very limited. Preferably the same organization that manages GSM and/or WCDMA shall be able to also manage LTE. LTE introduces new innovative solutions and key qualities that minimize the impact for today’s organizations when introduced. The key words such as Smart Simplicity and Self Organizing Network (SON) symbolize these solutions.
Self-Configuration Faster deployment Less parameters to worry about
Self-healing Automated recovery Automated fault isolation
Smart Simplicity Self-optimization Quality of Service Management Less tuning effort
Figure 6-16: Smart Simplicity - SON
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The design of LTE has a strong focus on what in general terms is named Smart Simplicity. Smart Simplicity aims at eliminating any increase in OPerational EXpenditure (OPEX) with LTE. It assures that any function designed for LTE RBS and RAN will provide smart support aiming at simplifying the operational task for the operator. It supports concepts such as Self Organizing Network and Automation. Self-Organizing Network (SON) is a set of requirements from operators on areas that are complicated from an O&M perspective. Some of the SON concepts are also being introduced in WCDMA systems. The reason for putting a focus on SON functionality in 3GPP is in the fact that operator cost in the area of planning, commissioning, configuration, integration and management of the network parameters are huge. SON will also help to minimize human and manual errors during the configuration of network parameters as the complexity of networks and multi-RAT environments increases. The figure below describes the benefits of SON.
Reduce OPEX
Minimize Human Error
A key goal is to support of SON features in multivendor network enviroment SON is a set of requirements from operators defined via 3GPP Figure 6-17: Why SON? Self Organization Network
3GPP is standardizing self-organizing capabilities that will automate most of the previous manual processes. In reality, operator’s networks are comprised from equipment from multiple vendors and therefore one of the goals is that SON features can be supported in a multivendor environment. LTE has, already from the start, a high level of automation. There are significantly less parameters to set. Only those absolutely necessary (that cannot be set by the system) need to be provided at integration. Default values for parameters are either preset by the system or controlled by the operator through policies. There is also support for simplifying processes where operator intervention is required. Fewer steps and faster execution limits the required time the operator spends on a certain process.
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Initial releases of the 3GPP specification have been functionality that is related to initial equipment installation and integration. Release 9 and later have focused more on the self-optimization and self-healing areas of network management.
+
› › › › › › › › › ›
Automatic RBS Integration Automatic Neighbor Relation Automated Mobility Optimization Automatic Physical Cell ID Assignment Automated RACH Root Sequence Allocation Overlaid Cell Detection PCI Conflict Reporting Advanced Cell Supervision Inter Cell Interference Coordination UE Level Oscillating Handover Minimization
Figure 6-18: SON Function Examples
The LTE RBS is tightly related to the OSS-RC (and soon in ENM) to enable the best smart simplicity design and implementation. Certain Smart Simplicity functions can be implemented in either or both of the RBS and the OSS-RC. This provides an implementation that is node efficient and which has network knowledge.
4.2
SON related features
4.2.1
Automated Neighbor Relations (ANR) ANR is a feature that automatically builds and maintains a neighbor cell list used for mobility. ANR adds neighbor relations to the cells when User Equipment (UE) measurement reports indicate that a possible new neighbor relationship has been identified. When this occurs, the RBS requests the UE to report the unique Cell Global Identity (CGI) of the potential neighbor cell. Using this information, the RBS automatically creates a neighbor relation between the serving cell and the new neighbor cell and mobility is facilitated.
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The figure below presents the enhancements of the ANR feature. Enhanced – L17.Q1: FAJ 121 0497 (FDD/TDD) › Description – This feature enables automatic optimization of neighboring list for intraand inter-frequency, GSM and WCDMA handover – Enhancement in L17.Q1: › When a PCI conflict is detected, ANR will mark this as a bad relation and request an ECGI measurement from the UE
› Operator benefit – ANR will reduce session drop rate – Reduced manual configuration work
Figure 6-19: Automated Neighbor Relations
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The concept is illustrated in the figure below: NR
TCId
6) Update Neighbour Relation table in RBS
1
123
No Del
2
234
X
(also updated in OSS)
3
345
X
4
456
No HO
No X2
OSS-RC
X X
EPC
Cell A PCI = 3 ECGI = 17
7) X2 interface set up if required
S1 interface
Cell B PCI = 5 ECGI =19
5) DNS Lookup (ECGI)
DNS
ECGI = E-UTRAN Cell Global Identifier & PCI = Physical Cell Identifier
Figure 6-20: ANR Operation
The figure illustrates that the UE (in step 1) sends the measurement report that initiates the ANR process. One of the most time consuming tasks in modern cellular networks is the optimization of handover and other mobility functions. ANR minimizes the need for manual configuration of neighbor cell relations. Based on measurement reports from UEs, the feature automatically constructs and maintains lists of the best neighbor cells.
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The figure below emphasizes that the addition/deletion of neighbors, although it is UEs that initiate the procedure, the operator does have control on the procedure.
Policy control for SON & ANR
NR Report
Manually Add / update / remove NR
Neighbor Relation Table (NRT) Neighbor Relation
O&M Controlled Neighbor Relation Attributes No Del No HO No X2
NR
TCId
1
123
2
234
X
3
345
X
4
X
Timer & Usage Information Remove
Update NRT
X
Neighbour Relation Table Management Function
456
Neighbor Detection Function
Add
ANR Function
RBS
Neighbor Removal Function
Measurement Request
Measurement Report
Figure 6-21: Automatic Neighbor Relations
ANR can be used together with manual optimization of neighbor lists and also removes neighbor cell relations that have not been used within a configurable time period. The following mobility functions are considered in ANR:
•
Intra-frequency handover
•
Inter-frequency handover
•
Coverage-triggered WCDMA handover
•
Redirect with system information to cells in GERAN and UTRAN networks
•
Coverage-triggered frequencies
session
continuity
with
redirect
to
Note: For pico RBS, the ANR feature only supports Intra-frequency handover and Inter-frequency handover.
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When a potential neighbor cell is reported in a UE measurement report, the RBS requests the UE to report the unique CGI of the potential neighbor cell. Using this information, the RBS automatically creates a neighbor relation between the serving cell and the new neighbor cell and handover is facilitated. Different types of UE measurements are used depending on type of neighbor relation. ANR orders UE to report strongest cell in UTRAN and GERAN networks to detect neighbor relations for those RATs. Detection of neighbor relations within the LTE technology is based on measurements with configurable thresholds. UE measurements of the following types are used to detect neighbor relations between LTE cells:
•
ANR initiated measurements triggered when a neighbor cell signal strength exceeds ANR-specific thresholds relative the serving cell
•
Mobility measurements triggered by mobility functions
The RBS controls both types of measurements by sending thresholds and other report conditions to the UE. The Automated Neighbor Relations feature can also initiate automatic establishment of X2 connections to eNodeBs with neighboring cells. E-UTRAN cell relations are removed when they have not been used within a configurable time period. When the feature Non-Planned PCI Range is activated, the defined PCI range cells shall not be added to the neighbor list by ANR and within the defined PCI range, the handover procedure shall always include CGI reading before handover. Note: For pico RBS, cell relations are not automatically removed. Without ANR neighbor cell relations can be manually maintained using OSS-RC. Benefits: By implementing ANR, the following is achieved: • Maintenance is reduced. •
Performance is improved.
•
New cells are introduced, with no need for neighbor relation planning.
•
Dropped calls due to missing neighbors are reduced.
When a site is down, ANR finds new neighbors.
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4.2.2
Automated Mobility Optimization The figure below presents the Automated Mobility Optimization enhancements.
› Enhanced – L17.Q1: FAJ 121 3035 (FDD/TDD) › Description – Feature includes functionality for optimizing handover, such as minimizing ’too late’, ’too early’ and ’wrong cell’ handovers – Know as Mobility Robustness Optimization – Enhanced in L17.Q1 › Improved algorithm to support tuning of 'overshooting cells‘
› Operator benefit – Improved network performance by more robust handover performance – Reduces the need for manual tuning of handover parameters for individual cells – Useful when e.g. densifying the network
Figure 6-22: Automated mobility Optimization
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4.2.3
Autointegration of RBS (Auto Provisioning) The aim of the integration is to minimize the amount of time, work and complexity at the site while integrating a new RBS site. It does mean that the network (O&M and traffic) must be prepared with the proper infrastructure and configuration for the autointegration to succeed. To provide flexibility, Ericsson also offers various tools (for example, with the laptop at the site or without), network requirements (for example, with IPsec or without) and degree of autointegration (fully auto or semi-automated procedures). Here a few important aspects of autointegration are shown: 1.
2.
3.
4.
5.
6.
Site
Site
Site
Define
Define S1
Add Radio
and X2
Network
BCM
BCM
Installation Basic
EM (onsite) Minimal data
EM
Equipment RBS
EM
ARNE
7. Unlock
BCM
8. Make Test session
Manual AutoIntegration
BSIM
OSS-RC Server OaM Infrastructure
Installer powers on the eNodeB and enters a minimal set of data
Figure 6-23: Autointegration of RBS (macro)
In the figure above, it shows that there are several configuration stages to make an RBS fully operational (check the top row.) If one performed those configuration stages with “manual procedure”, several applications would be required, and coordination between the OSS-RC engineer and the on-site integrator is also necessary. While performing the autointegration, many of these configuration stages are pre-prepared beforehand and coordinated by the BSIM application (in the OSS-RC) during the integration. The on-site personnel would only require a few parameters to be fed in at the site through his/her laptop. (The details of the servers and components are not shown in the figure above.) To simplify the integration even further for the on-site integrator, a smartphone might be enough, if it has the correct app (called ENIS).
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The procedure, from the site perspective, is shown in the figure below:
1. Install RBS physically 2. Read and send bar codes from app, together with the sitename 3. Turn on power in RBS 4. Monitor integration progress via LED Work order Site name:
(Positioning)
Harbor Street 84
Site name= Harbor Street 84 SerialNumbe r= 69204FXCG 3284
ENM / OSS-RC
Prepared config
HW: SerialNumber=69204FXCG3284
Apply configuration
Figure 6-24: Auto-Integration Using a smartphone – Site Perspective
What is obvious from the figure above is that network (e.g. OSS-RC and the infrastructures) are pre-configured with RBS specific data beforehand. The onsite person simply needs to send the hardware and the site information to the network, power on the RBS and the integration is initiated. Since no laptop/computer is present at the site, the LED on the RBS indicates when the integration is successful. The procedure described here is often referred to as the zero configuration (at site), and is an important enabler for small cell deployment (with micro- and pico RBSs). Network Provisioning
Node Provisioning
Node Commissioning
Node Integration
Prepare NW Infrastructure
Prepare for Node Configuration
Node Specific Configuration
Autonomous Node Integration
Deploy and configure / reconfigure servers
Pre-configure individual / batch of nodes using templates
Bind physical RBS id to logical configuration
Power up RBS
At infra structure changes
Large group of nodes
Per node, or group of nodes
Per node
Figure 6-25: Pico/micro RBS Auto-integration
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The details of these steps are not covered here. The Customer Product Information (CPI) contains the details on how to provision a new RBS. The onsite integrator is involved in the last two steps- to provide the RBS physical identity (as exemplified in the previous figure), and powering on the RBS. Powering up of the RBS is the last stage in this auto provisioning model. This powering on of the RBS initiates the download of the necessary configuration file, upgrade of the node (if required), contacting the DHCP/DNS servers, setting up the IPsec tunnels (if required), configuration of the transport and radio network parameters and informing the OSS-RC that it is ready for service!
4.2.4
Automatic PCI assignment Cells are identified locally by 504 signal sequences, each associated to a Physical Cell Identity (PCI). PCIs are used in the LTE network as a way for mobile devices to distinguish between different cells. The available numbers of PCIs are 504 but an LTE network may contain a much larger number of cells. Thus, the same PCI must be used by several cells. However, a mobile phone cannot distinguish between two cells if they have the same PCI and the same frequency. PCI confusion is when UE in an eUtran cell can hear two different neighbor eUtran cells with the same PCI and frequency. PCI collision is when an UE is in one eUtran cell and can hear another eUtran cell with the same PCI and frequency. Automatic PCI Assignment functionality is provided to calculate PCI values for new and existing cells so as to minimize risk of PCI collisions occurring when new cells are being added to the network. It can also be used to identify potential PCI collisions with neighbors.
› PCI similar to scrambling code in WCDMA › 504 potential PCI values within LTE network › Auto PCI calculates PCI values for new and existing networks › Auto PCI selection can adapt to evolving network › Minimizes risk of PCI collisions PC I = 3 PC I = 300 PC I = 66 PC I = 59
PC I = 99 PC I = 1
PC I = 200 PC I = 25
PC I = 2
Figure 6-26: Automatic PCI Assignment
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Most PCI conflicts can be avoided by applying a good PCI plan. However, it can be difficult to do a PCI plan without getting any PCI conflicts if the network is dense. Furthermore, PCI conflicts can also occur if the network is changed for example increased power of a cell or cell range expanded or changed with other means. Changed radio conditions may also results in that an UE in a cell can hear a cell that was not expected when the PCI plan was done. The PCI Conflict Reporting feature is a licensed feature that automatically detects PCI confusions and collisions. PCI confusion and collision are detected based on configured relations, that is, PCI confusion is detected if an eUtran cell has neighbor cell relationship configured for mobility to two eUtran cells where both cells have the same PCI and frequency. PCI confusion is also detected using X2 functionality, that is, PCI confusion is detected using neighbor information that is sent in X2 setup and eNB configuration update. The PCI Conflict Reporting feature is activated for each RBS and licenses are always checked at cell level before performing PCI conflict detection. The Figure below illustrates the concept of PCI conflict.
› Conflict can occur when ANR adds a cell to a neighbor list with the same PCI already existing › Feature automatically detects PCI conflict and reports to OSS
PC I = X
PC I = X
Figure 6-27: PCI Conflict Detection
A UE cannot distinguish between two cells if they have the same PCI and the same frequency. A handover may fail when the PCI that is included in the measurement report does not uniquely identify the cell. The PCI Conflict reporting feature detects when PCIs does not uniquely identify the neighbor cells, that is, detects PCI confusions. Thus, a faulty configuration can be detected automatically and this makes it possible to resolve the PCI conflict fast. This will improve handover statistics caused by PCI confusion and thus performance.
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Having this feature enabled will also improve the general operating quality of the network and removes the need to manually perform this time consuming and complex task of PCI planning and PCI which will reduce the overall cost involved in the OPEX of the network.
4.2.5
Advanced Cell Supervision The ‘Advanced Cell Supervision’ (ACS) feature automatically supervises cells in the RBS using a set of ‘detectors’. A detector is a set of internal events that provides indication of the traffic condition in the cell. These detectors could be used to find “sleeping cells”- cells that seem to be working but do not accept UEs or traffic. Sleeping Cell detected by PM statistics => Not quick enough
Z
Z
OSS-RC
Z
X ZZ X X
Advanced Cell Supervision: ›
Detect
›
Try to fix
›
Report to OSS-RC
Figure 6-28: Advanced Cell Supervision Overview
There are five detectors that ACS feature uses to suspect a sleeping cell:
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•
Detector 1: if a certain number of random access preamble attempts Random Access RA Msg 1 divided by the average number of Radio Resource Control (RRC) connected UEs are detected during a measurement period but when there is no detection of successful RRC connection setup, incoming handovers or user-plane traffic.
•
Detector 2: if a certain number of Mobile Originating Data (MOD) RRC connection requests are detected during a measurement period but when there is no detection of RRC connection setups or user-plane traffic.
•
Detector 3: if a certain number of random access preamble successes (RA Msg 3) are detected during a measurement period but when there is no detection of successful RRC connection setups, incoming handovers or user-plane traffic.
•
Detector 4: if the previous measurement period has a certain average number of RRC connections but the existing measurement period has no RRC connections.
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•
Detector 5: if no PDCP or MAC traffic is detected in the cell during the measurement period.
ACS runs in the RBS, collecting information from different detected sources, and is supported by self-healing tools those can even include lock and unlock actions. If unsuccessful recovery actions are done, or recovery actions shall not be used, an alarm is sent directly a detector are suspecting a sleeping cells.
4.2.6
Inter-Cell Interface Coordination Inter-cell Interference Coordination, located in eNB, has the task to manage radio resources (notably the radio resource blocks) such that inter-cell interference is kept under control. ICIC is inherently a multi-cell RRM function that needs to take into account the resource usage status and traffic load situation of multiple cells. In the downlink, inter-cell coordination implies restrictions of the transmission power in some parts of the transmission bandwidth. In principle, this parameter could be configured on a static basis; however, this is not very efficient. Instead dynamic, downlink coordination is supported through the definition of a relative narrowband transmission-power indicator.
› This allows for cell edge users (high tranmission power) to be assigned different Resource Blocks to avoid excessive interference between users on different cells More BW, lower power
More power, separated in frequency
Figure 6-29: Inter Cell Interference Coordination - ICIC
A cell can provide this information to neighboring cells, indicating the part of the bandwidth where it intends to limit the transmission power. A cell receiving the indication can schedule its downlink transmissions within this band, reducing the output power or completely freeing the resources on complementary parts of the spectrum. A crucial part of the supported inter-cell-interference coordination scheme in LTE is that full-frequency reuse in neighboring cells is possible.
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Uplink inter-cell interference coordination consists of two inter-related mechanisms. The first part is a pro-active ICIC mechanism using the highinterference indicator. The basic idea of this scheme is that a potentially disturbing eNB pro-actively sends a resource block specific indication to its potentially disturbed neighbor. This message indicates which resource blocks will be scheduled (with a high probability) with high power (i.e. by cell edge UEs). Thus this message allows the receiving eNB(s) to try to avoid scheduling the same resource blocks for its cell edge UEs. This way the pro-active scheme allows neighbor eNBs to reduce the probabilities of “exterior-exterior” (i.e. cell edge) UEs to simultaneously take into use the same resource blocks. In addition, the 3GPP also defines the use of the overload indicator (OI). As opposed to the pro-active scheme, the overload indication is a reactive scheme that indicates a high detected interference level on a specific resource block to neighbor eNB(s). A cell receiving the OI may reduce the interference generated on some of these resource blocks by adjusting its scheduling strategy, for example, by using a different set of resources, and in this way, improve the interference situation for the neighbor cell that issues the overload indicator.
4.2.7
SON Optimization Manager Ericsson’s SON Optimization Manager is a multi-vendor, multi-technology product for the continuous optimization of mobile networks. Continuous optimization gets the best out of existing network investments and gives operators benefits in OPEX reduction and increased revenue from improved service quality and capacity. The use cases offered give operators the chance to reap the benefits of SON functionality today. Ericsson SON Optimization NMS
Manager
› Multi Vendor › Multi Technology
Standardized and Open Interfaces
OSS
Ericsson
Ericsson
Other
OSS
OSS
Vendor OSS
LTE
WCDMA
NE WCDMA (other vendor)
Figure 6-30: SON Optimization Manager
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The SON Optimization Manager is a node at NMS level hosting centralized SON use cases. The SON use cases in the SON Optimization Manager are those requiring a wide network visibility (i.e. decisions requiring coordination of several elements and domains) which can be achieved from a centralized location, while at the same time real-time reaction is not a must. Also, its location in the NMS hierarchical level provides the SON Optimization Manager with capability to extend optimization to several technologies and vendors in a holistic manner. The key paradigm of the SON Optimization Manager is always-on, zero human intervention. The optimization use cases are fully autonomous, from data collection to activation of changes in the network, requiring no OPEX expenditure to run. Furthermore, the product is seamlessly integrated with the network, so that operating it is transparent to engineers except for the performance benefits it provides. The SON use cases (including WCDMA and LTE) available in release SON Optimization Manager 14.2 are:
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3G Centralized Automated Neighbor Relations (C-ANR). Provides automated, continuous optimization of neighbor relations of every type: intra-frequency (IAF), inter-frequency (IEF) and inter-Radio Access Technology (IRAT). Once C-ANR is started, neighbor plans will automatically be tuned continuously, with zero hassle.
•
3G ID Optimization (IDO). Ensures an optimum scrambling code plan in an automated manner. This use case is integrated together with the CANR use case. This capability is only applicable to NSN and Huawei CANR.
•
3G Coverage & Capacity Optimization and Load Balance (CCLB). Coverage and Capacity Optimization (CCO) and Centralized Mobility Load Balance (MLB), although defined separately by 3GPP and NGMN, are intricately interlocked in WCDMA networks. Ericsson´s solution combines both together with a holistic optimization aimed at containing interference (Interference Management). CCLB optimizes over thirty cell and neighbor relation parameters to enhance quality, coverage and capacity.
•
Adaptive Automatic Neighbor Relations (A-ANR). Extends C-ANR time granularity by allowing optimization in sub-day patterns (up to 15 minutes periodicity), which allows adjusting to intra-day traffic events such as hotpots and sites going out of service.
•
Adaptive Load Balance (A-LB).Provides continuous, autonomous optimization of over 10 Ericsson WCDMA Radio Access Network parameters related to load balancing, realizing traffic management at intra-frequency, inter-frequency and inter-RAT level. This feature is mainly driven by capacity offloading and balancing, considering the effects on quality and coverage aspects. A-LB allows optimization in sub-day patterns (up to 15 minutes periodicity), which allows adjusting to intra-day traffic events.
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•
LTE Coverage & Capacity Optimization and Load Balance (CCLB). Extends the WCDMA functionality in CCLB to LTE RAT. LTE CCLB is a solution comprised of the following features: o
Remote Electrical Tilt Optimization
o
Inter-RAT Handover Optimization
SON Optimization Manager 14.2 supports Ericsson, NSN and Huawei WCDMA RAN, as well as Ericsson’s LTE RAN. All adaptive use cases are supported for Ericsson RAN while A-ANR is supported also for NSN RAN.
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5
HARDWARE MANAGEMENT FEATURES
5.1
Multi-cabinet Control The optional feature Multi-cabinet Control provides the capability of controlling multiple RBS cabinets for Support System functionality: Climate Control, Power Control, and External Alarms. The main benefits of Multi-cabinet Control are: •
Operator can build Multi-Standard configurations spanning over Multiple RBS Cabinets, for instance when deploying LTE Inter-Band Carrier Aggregation, where the Radio Units of the different frequency bands are distributed over multiple Macro RBS cabinets.
•
Individual Climate, Power and External Alarms Control per RBS cabinet.
The HW solution for providing interconnection between a DU in one Macro RBS cabinet and an RU in different Macro RBS cabinet are based on XMU03. For XMU03 connection to Support System Hub Unit a new Ericsson cable converter product, mUSB to RJ-45 converter, must be used. The XMU or Auxiliary Multiplexing Unit will be discussed in a separate part which is also a new hardware feature in L14B. The existing functionality for Support System, Climate Control, Power Control, and External Alarm Control are instantiated per RBS cabinet to have individual Support System Control per RBS cabinet. One limitation is that the same power solution has to be used in all cabinets. WCDMA lacks support to control the XMU03. This means that WCDMA is the secondary node in a multi-standard configuration.
5.2
Antenna System Monitoring When using multiple antenna techniques in a wireless communication system such as, RX diversity, TX diversity, or Multiple Input Multiple Output (MIMO), the antennas must align well in order to achieve the expected gain. Problems with the antenna greatly impact the quality of the mobile system. At multiple antenna installation, the feeders can be installed incorrectly, leading to low antenna performance. Drive testing is often used to discover and correct such errors, which can be expensive. The procedure on how the Antenna System Monitoring works may be described as:
1
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2
The difference of the SINR between each pair of receiver antennas is calculated and the corresponding counters are stepped.
3
Operations Support Systems-Radio and Core (OSS-RC) and Ericsson Network IQ (ENIQ) collect the counter values and the Find Faulty Antenna - LTE in ENIQ can be used to calculate the mean and standard deviation. From these values, the conclusion and the level of reliability are determined and presented and when required, an alarm is raised in OSS-RC.
The conclusion in this case is any of the following:
•
No failure
•
Misaligned
•
Swapped
•
Disconnected
•
RF Path Losses
OSS alarms will be generated when problems requiring operator intervention are detected.
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An example of how the Antenna System Monitoring can help find faults is shown in the following figure: › Antenna System Monitoring monitors L1 baseband measurements (counters) in each of the received paths.
Sector 1 UE0
– Alarms will be generated when problems requiring operator intervention are detected
Antenna 0
Sectorl 0 UE1
› The feature supports receiver antenna configurations of 2, 4 and 8 with a basic comparison unit of two antennas, with differences calculated between each pair › Managed from OSS - Included in ROP file
Sector 2 Antenna 1
Improper connection: – There are two antennas in sector 0 – One antenna is connected to sector 2
Figure 6-31: Find Faulty Antenna
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6
OTHER LTE RBS KEY O&M FEATURES All the O&M features described earlier are possible to perform in the RBS also (using the Element Manager or COLI in the G1 RBS), except the performance management functions that require the activation from the OSS-RC. This section describes the other primary O&M functions that characterize LTE RBS which were not covered earlier.
6.1
Fault Correlation Rule Engine The LTE RBS includes a rule engine that contains recovery and correlation rules that all fault indications are processed in before alarms are issued. Rules included are for instance how recovery shall be done in case of a certain faults, for instance, which self-test to run and which level of restart stairs shall be used. There are also rules defining correlation between different fault indications. It also contains rules regarding blocking hierarchy for mitigation of the fault. The rules are predefined and included in the RBS software. They are updated with the release of new versions of the RBS software. All resources are supervised, both software and hardware. In case of a fault condition the RBS will first try to correct it by itself before any notification is issued (i.e. alarm is sent to OSS-RC). The RBS will use built-in self-tests and restart functions of both HW and SW to correct the failing entity. It will correlate the different fault indications to assure that any reported fault is really a concrete fault that requires action from the operator. This will remove the risk of multiple alarms for the same fault and toggling alarms due to intermittent faults. When the fault is determined it will mitigate the consequence of the fault to a minimum by, for instance, disabling a faulty unit. It will try to maintain traffic as much as possible. The fault condition is indicated with an alarm and, if a board is faulty also with a LED on the board. The alarm contains the necessary information for fast identification of actions to take, including unit to replace. All alarms are logged, for historical reference purposes. They are automatically sent to OSS-RC. In addition to the built in self-test used for fault mitigation it is possible to manually order tests. The tests verify all essential functions and report back the result to the operator. Through the cabinet viewer it is possible to view actual status of the hardware remotely. It will present the status for each unit on a graphical layout OSS-RC stores, logs and presents the alarm to a user. It also executes any subscription for forwarding the alarm to an NMS. The user at the NOC can utilize a range of different tools for remote trouble-shooting and actions on the fault. For instance the FM feature allows browsing of alarms and alarm history; the LTE Explorer allows correlation (in GUI) of alarms with both PM and CM information and the RBS Element Manager allows for detailed trouble-shooting. The GUIs of these different applications are tightly integrated.
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6.2
Plug and Play of Hardware The RBS supports Plug’n Play for replacing hardware units. No manual intervention other than the actual HW replacement is required. The RBS will automatically load and configure the new hardware unit and indicate when it is ready with a steady green LED on the unit. No node restart is needed and there is thus no node downtime, but the cells served by the replaced unit may be down 10-20s during the configuration. Replacement of the digital unit is different compared to replacement of other units. It requires human interaction as this unit contains the configuration data of the RBS and this data need to be restored.
6.3
Co-siting and Mixed Mode Support The LTE RBS can be co-sited with Ericsson GSM and WCDMA RBSs. The O&M solution supports coordinated O&M for the common hardware such as antennas etc. Only one of the logical RBSs will supervise the common hardware. In OSS-RC indication of faults will be shown on all logical RBSs on the site. A site manager in OSS-RC will provide extensive support for site management including managing the common hardware. From a logical perspective the co-sited RBSs are still different RBSs as they serve different networks. In OSS-RC seamless support for managing WCDMA and LTE networks will be provided. For instance, a common Explorer will enable working with WCDMA and LTE networks at the same time. ENIQ (Ericsson Network IQ) in OSS-RC enables the combination of GSM, WCDMA and LTE KPIs for correlated KPI reporting. Mixed Mode implies that the some equipment is shared in the same RBS site. If only the support/climate system is shared, it is referred to as Multi Standard Single Mode (MSSM), while if the (remote) radio unit is shared between two radio access technologies, then it is referred to as Multi Standard Mixed Mode (MSMM).
6.4
Direct Reading of KPIs It is essential when trouble shooting radio performance that both historical - i.e. statistics over time - and current data are available. Collected statistics can be up to two hours old before being available. Current data provides a snapshot of current status. With this feature it is possible to immediately get the result from the latest Recording Output Period (ROP) that is currently open for collecting KPI input. It enables counters and KPI data to be available now when needed. The feature is used through the command interface in the RBS and can be used through AMOS in OSS-RC or the Element Manager, enabling both local and remote access abilities.
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6.5
Shared Network Support With the Shared LTE RAN feature, up to six operators (that is, with up to six PLMNs) can share an LTE RAN. Among all possible shared network configurations, the Shared LTE RAN feature supports the following configurations:
•
Gateway Core Network (GWCN): Both eNodeB and Mobility Management Entity (MME) are shared by two or more operators.
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Multi Operator Core Network (MOCN): Two or more operators share an eNodeB. The cell is also shared.
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Split in eNodeB or Multi Operator RAN Network (MORAN); A variant where two or more operators share an eNodeB, but the different operators have their own cells.
The Shared LTE RAN feature allows the operators to share a common RAN. This provides operators with substantial cost reductions and a reduced environmental footprint.
6.6
Minimization of Drive Tests For operators, the traditional drive test where vehicles with measurement equipment are used for analyzing network coverage and capacity, is costly and needs much planning and coordination of resources. It is desirable to use automated drive test solutions, including involvement of UEs in the field. The 3GPP have specified ‘Minimization of Drive Tests’ (MDT) so that standard mobiles can be used for measurements to provide network analysis data and UE location information for the operators. MDT provides a simpler, cheaper, and remote method to use for troubleshooting or verification of the radio network. The Ericsson ‘Minimization of Drive Tests’ new L16B optional features introduces support for Area-based Immediate MDT using M1 (RSRP and RSRQ) intra-frequency measurements from UEs, M3 (Noise and Interference) measurements and M4 (data volume) from. The M1 measurements can contain GNSS (Global Navigation Satellite System) positioning if available in the UE according to 3GPP release 10 or above.
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Measurements to be performed for Immediate MDT purposes involve reporting triggers and criteria utilized for RRM. M3 MDT Measurements: - Received Interference Power M4 MDT Measurements: - UL PDCP traffic volume per QCI - DL PDCP traffic volume per QCI
LTE CELL TRACE EVENTS:
OSS
Collected by OSS or streamed to suitable Events server eNodeB
Simple, cheap remote Troubleshooting
RRC Measurement Reports
M1 MDT Measurements: - Intra-frequency RSRP - Intra-frequency RSRQ - GNSS location (if available)
Figure 6-32: Minimization of Drive Tests - MDT
In addition, there are measurements performed in eNB. The measurements M1 toM5 shall be supported for Immediate MDT performance. The M1, M3 and M4 measurements are collected by the LTE Cell Trace Internal Events as shown here. These events may be stored in ROP files on the eNodeB and handled by the OSS in the normal way or streamed to a suitable events server. Since the ‘Minimization of Drive Tests’ feature uses the GNSS device in the UE it can have an impact on battery consumption.
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7
SERVICES Ericsson offers a variety of services in the LTE RAN area to help operators concentrate on managing their core business and let Ericsson take care of the operating the network. Examples include the “Managed Services”, “Network Rollout Services”, “Network Design and Optimization Services” and “Learning Services”. An interesting addition to these services is Ericsson’s Proactive Support Services, which is described here.
7.1
Proactive Support Services Ericsson helps Operators with early detection and incident prevention in network O&M. The right way forward is to pin-point problems earlier – localize the problem, avoid it or resolve it faster. This service is gathering global intelligence to help identify & prevent problems in the network. Operators are increasingly challenged to find a balance between profitability and quality. The current market trends indicate that data traffic is growing tremendously, end users are putting more demand on what the network and complexity is driven by increased number of node types, platforms and technologies. All these challenges add pressure on network O&M. Operators need to continuously evolve the network in order to accommodate the data traffic growth. At the same time, the team has to improve efficiency and continue to develop competence to address network complexity. Key challenges facing the operator include, technology evolution, responding to end-user demand, operational efficiency and O&M competence. Frequent changes in operator networks generate more faults and impact the network performance. Operators are looking at innovative solutions that reduce OPEX spend while addressing these challenges. Network downtime impacts operator credibility and subscriber satisfaction. Operators have to monitor networks in real-time to identify issues and resolve them faster. New technologies add network complexity that increases demands on the customers’ operations team. Increasingly O&M teams are looking at new automated tools to cope with increasing demands of these complex networks. They are often forced to deal with multiple high priority issues, which may result in reduced priority for regular maintenance activities which includes ensuring consistent configuration, deleting accumulated files, and capacity monitoring.
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SUMMARY The students should now be able to: 6. Describe O&M (Operation and Maintenance) for EPS 6.1 Describe OSS-RC 6.2 Describe ENM 6.3 Explain the concepts related to Smart Simplicity and Self-Organizing Networks (SON) h
Figure 6-33: Summary of Chapter 6
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7 The Road to 5G
Objectives On completion of this chapter the students will be able to: 7. Describe the road to 5G 7.1 Give examples of deployment scenarios in 5G 7.2 Briefly about the evolution of LTE 7.3 Present the Massive MIMO technique 7.4 Describe Cloud solution 7.5 Explain v-RAN ideas 7.6 Present the Ericsson Radio System deployment for 5G Figure 7-1: Objectives of Chapter 7
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5G BACKGROUND AND CONCEPTS
1.1
Mobile Subscriptions Growth In the past 30-40 years, the world has experienced a change greater than that of the industrial age. This chart highlights the phenomenal pace of change, which connected five billion in only 25 years. And while we are already seeing the vast benefits of a world where five billion of us are connected, just imagine what a world will look like when everything is connected. Commercial 5G networks based on ITU standards are expected to be available in 2020, and early deployments of pre-standard networks are anticipated in several markets. By the end of 2022, it is expected 550 million 5G subscriptions and a population coverage for the technology of 10 percent, starting in metropolitan and urban areas. In addition to enhancing mobile broadband services, 5G will enable a wide range of use cases for the Internet of Things (IoT). Ericsson continues to forecast IoT connections, this time describing the split between wide-area and short-range connections. The interest in launching pre-standard 5G networks has increased over the year and deployments before 2020 are anticipated in several markets. Early 5G deployments are driven by the need for enhanced mobile broadband services, and as a complement for fixed internet services – referred to as Fixed Wireless Access (FWA). In addition, 5G will enable a wide range of use cases for the IoT. GSM/EDGEonly subscriptions are still the largest category of mobile subscriptions. However, LTE is anticipated to become the dominant mobile access technology in 2019, and reach 4.6 billion subscriptions by the end of 2022. In 2022, the number of LTE subscriptions will be more than five times higher than GSM/EDGE-only subscriptions, while the number of WCDMA/HSPA subscriptions will be three times higher. In developing markets, GSM/EDGE will remain a viable option, and the majority of 3G/4G subscriptions in all regions will still have access to GSM/EDGE as a fallback. GSM/EDGE will also continue to play an important role in IoT applications. The number of mobile subscriptions continues to grow across the regions, fueled by the strong uptake of mobile broadband subscriptions. The mobile broadband subscriptions now make up more than 50 percent of all subscriptions. Many consumers in developing markets first experience the internet on a smartphone, mainly due to limited access to fixed broadband. Greater device affordability is encouraging new subscribers in developing regions, while growth in mature markets is largely due to individuals adding more devices.
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In Middle East and Africa, where the penetration of mobile broadband is currently lower than in other regions, the growth in mobile broadband subscriptions is expected to be particularly strong moving forwards. A driving factor is the growing economy in several countries, supported by a young and growing population and more affordable smartphones. The Figure below presents the Mobile subscriptions by technology (billion).
Figure 7-2: Evolution of Mobile Broadband
The Figure below presents the Mobile subscriptions by region (billion).
Figure 7-3: Mobile subscriptions by region (billion)
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Over the forecast period, Middle East and Africa will dramatically shift from a region with a majority of GSM/EDGE-only subscriptions, to a region where 80 percent of the subscriptions will be WCDMA/HSPA and LTE. However, GSM/EDGE-only subscriptions will still account for a significant share of subscriptions by 2022. In Latin America, WCDMA/HSPA and LTE already account for around 60 percent of all mobile subscriptions – a number that is expected to increase to 90 percent in 2022. Asia Pacific is a diverse region. Despite ongoing deployment of LTE in China, which will result in more than 1.2 billion LTE subscriptions in the country by the end of 2022, LTE subscriptions will represent just 50 percent of all subscriptions in the region by the end of the same period. This will be around one quarter of the global total. 5G subscriptions will account for around 10 percent of all subscriptions in the region in 2022, with deployments starting in South Korea, Japan and China. All three of these countries will host Olympic games in the coming six years, and have stated intentions to launch 5G services in conjunction with the games. In Central and Eastern Europe, the share of LTE subscriptions is anticipated to grow strongly from around 10 percent in 2016 to 70 percent of all mobile subscriptions in 2022. In Western Europe, the share of mobile broadband subscriptions is high due to well-developed WCDMA/HSPA networks and early LTE rollout. The regional share of 5G subscriptions will be 5 percent in 2022. Overall, North America is the region with the highest share of LTE subscriptions due to rapid migration from CDMA and WCDMA/HSPA-based networks. In 2022, the region will have the highest share of 5G subscriptions at 25 percent.
1.2
5G impact on Network Society As the term implies, a ‘Networked Society’ is about more than how a network shapes the fortunes of a business or the quality of someone’s life. It is about society that will fundamentally change the way we innovate, collaborate, produce, govern and achieve sustainability. In ancient Greek history the term Golden Age was used in reference to a period of great inventions, peace, harmony, stability and prosperity. Whilst this ideal world might not originally have been one that featured such things as 3D Printers, Smart Meters and Self-Driving Vehicles, the potential outcome from these innovations may well be the same. The Networked Society leans forward offering a glimpse into a New Golden Age for Mankind. One where every person and every industry is empowered to reach their full potential.
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1.3
5G impact on ICT – Information and Communications Technology As we look at the world a decade after everything is connected, it’s feasible to start making predictions for what things might look like in 2030. In our journey through a time of Exponential Innovation and ICT Empowerment, it is possible to start winding forward to a time when it’s quite realistic that we will experience the things like: millions of people walking the planet with a life expectancy of 150 years; food serving big cities being grown in sky scrapers; buildings generating more energy than they consume; actors being replaced by animated artists; and people who will never know what it is to drive a car.
1.3.1
New practices needed Systemic change will be necessary if we are to realize the advantages of the Networked Society. At Ericsson we see six core shifts or new practices that we believe can help both companies and organizations sustain this change: •
Digitalize business resources: As processes and products become digitalized, organizations are increasingly adaptable to a changing environment, enabling increased innovation, strengthened decision making and value creation.
•
Make sense from data: Real time data analytics are empowering individuals and decision makers alike to make informed decisions based on user information.
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Establish Network Practices Network focused management practices are critical for the delivery of scalable digital platforms and services, empowering a better understanding of prioritizing those resources that are owned, managed and shared.
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Encourage user co-creation: Digital networks are making co-creation and collaboration easier via online communities, and businesses and governments can now improve relationships with customers and citizens using digital products and services.
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Develop new platforms: The inevitable transformation of business will be led by a new economic model driven by technology, with powerful businesses platforms based on search, social media and e-commerce.
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Innovate in service business: A collaborative approach from governments, businesses and communities will fundamentally drive different models based on networks that will lead to societal transformation and more powerful innovation.
With these practices in place, over the next few decades we will see significant changes in society.
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The past few decades of ICT progress have undoubtedly been instrumental to change but we have experienced mainly incremental differences along the way. After all, whether you’re using a fixed-line, or mobile device, it’s still a phone. When we look at ICT beyond the inflection point we see that social networks represent the real departure from the telephone. In addition, thanks to the ability to share any variety of physical goods and consume digital content such as music and video, the very idea of ownership is reimagined. It’s less about ownership and more about access. This change is enabled by what we call ‘general purpose’ technologies. Steam, coal, iron and railways were general-purpose technologies in the Industrial Age. The significance of these technologies became more important as they stretched into other industries and started to bring about society wide transformation. In the ICT world today, these general-purpose technologies are Mobility, Broadband and the Cloud. They have passed the first installation-phase curve and are now on their way to the transformation stage. They are becoming the foundation for all other areas of society to operate and innovate upon. All have broad applicability going far beyond the ICT industry that created them, and are starting to drive transformation.
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2
THE STANDARDIZATION 5G requirements are based on use cases rather than traditional technologyoriented capabilities. These are the Next Generation Mobile Networks (NGMN) use case families mapped to both use case categories (in the middle) and individual use cases (at the bottom). What does Pervasive Video mean? -> Video everywhere What does Tactile internet mean? -> “Sense of touch” or haptic internet So, technically, early enhanced Mobile broadband experience is definitely a use case that the operators consider to be an opportunity with 5G technology. But it would be “just another G” if 5G wouldn’t bring something more in terms of use cases? The benefits of 5G really will come from their multitude of use cases, which will progress as the technology evolves. Based on ITU categorization of three categories of Use Cases (at the top); eMBB (fiber-like experience, Gbps speeds at cell-edge) Critical MTC (low latency, reliability, security high BW) and Massive MTC (cost efficient sensors, large coverage, low BW) – the operator NGMN alliance (representing 1/3 of all mobile operators, vendors, manufacturers, research institute etc. break down these in a range of different potential use cases that could be realized with 5G. eMBB: Capacity boost in dense areas, Gbps to the cell-edge, higher user mobility => will open up for new range of user experience; smart offices, 3D, virtual reality and UHD video in larger app coverage areas Critical MTC: extreme real-time comms, automated traffic control and driving, remote surgery, remote hazardous work (machinery, mines etc.), ultra-reliable comms Massive MTC: support already in LTE, but will evolve with more sensor networks, smart wearables and the like Moreover, the dynamic and programmable nature of 5G networks will likely open up the ability for enterprises to purchase “slices” of the networks for business uses. Called “network slicing,” this feature will allow sensors and devices to request resources from the network.
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The Figure below presents the overall of 5G Standardization.
Figure 7-4: 5G Standardization
2.1
3GPP September 2015 a 5G Workshop has been held in Phoenix (USA) which covered the full range of requirements that will feed TSG RAN work items for the next five years. In his Workshop Summary (RWS-150073), has been highlighted three high level use cases to be addressed: •
Enhanced Mobile Broadband
•
Massive Machine Type Communications
•
Ultra-reliable and Low Latency Communications
New radio There is an emerging consensus that there will be a new, non-backward compatible, radio access technology as part of 5G, supported by the need for LTE-Advanced evolution in parallel. The Workshop Summary stressed the need for “forward compatibility to be a design requirement for the new radio from the get-go” with the Study to “include careful investigation of design options to ensure forward compatibility for all use cases.” Phasing There will be two phases for the eventual specification work:
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Phase 1 to be completed by H2 2018 (End of 3GPP Release 15) Phase 2 to be completed by Dec 2019 for the IMT 2020 submission and to address all identified use cases & requirements (End of 3GPP Release 16) LTE Advanced Pro 3GPP has approved a new LTE marker that will be used for the appropriate specifications from Release 13 onwards. LTE-Advanced Pro will allow mobile standards users to associate various new features – from the Release’s freeze in March 2016 – with a distinctive marker that evolves the LTE and LTE-Advanced technology series. The new term is intended to mark the point in time where the LTE platform has been dramatically enhanced to address new markets as well as adding functionality to improve efficiency. The major advances achieved with the completion of Release 13 include: MTC enhancements, public safety features – such as D2D and ProSe - small cell dualconnectivity and architecture, carrier aggregation enhancements, interworking with Wi-Fi, licensed assisted access (at 5 GHz), 3D/FD-MIMO, indoor positioning, single cell-point to multi-point and work on latency reduction. Many of these features were started in previous Releases, but will become mature in Release 13. As well as sign-posting the achievements to date, the introduction of this new marker confirms the need for LTE enhancements to continue along their distinctive development track, in parallel to the future proposals for the 5G era. The 3GPP Project Coordination Group approved the use of LTE-Advanced Pro at their meeting in Vancouver the week of October 19, 2015.
2.2
METIS METIS, Mobile and wireless communications Enablers for Twenty-twenty (2020) Information Society. Ericsson initiated and took lead to begin the first EU research project on 5G. This project called METIS started November 1st, 2012 and the project ended 2015. The METIS consortium consisted of six vendors, five operators, 13 academic organizations, and BMW as a representative of the verticals. Are there any benefits of having so many partners in one project? Yes indeed. It allows us to address scenarios from different angles than we traditionally do, and having representatives from the verticals enables us to think outside the box.
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METIS is followed by METIS-II and other projects within Horizon 2020/5G PPP. The METIS-II builds on the successful METIS project and will develop the overall 5G radio access network design and to provide the technical enablers needed for an efficient integration and use of the various 5G technologies and components currently developed. METIS-II will provide the 5G collaboration framework within 5G-PPP for a common evaluation of 5G radio access network concepts and prepare concerted action towards regulatory and standardization bodies.
Platform/components
Main forums
Supporting activities
3GPP = 3rd Generation Partnership Project ITU = International Telecommunications Union NGMN = Next Generation Mobile Networks GSMA = The GSM Association IEEE = Institute of Electrical and Electronics Engineers IETF = Internet Engineering Task Force MEF = Metro Ethernet Forum TM Forum = TeleManagement Forum OPNFV = Open Platform for NFV Project
Figure 7-5: 5G Standardization Forums
In the figure above, from the right to the left we see Platforms and Components for Virtualization technologies, protocol stacks etc. that we need as a foundation for the platforms so we can run all the functions for 5G. Open Platform for NFV (OPNFV). OPNFV is a new open source project focused on accelerating NFV's evolution through an integrated, open platform. The OpenDaylight Project is a collaborative open source project hosted by The Linux Foundation. The goal of the project is to accelerate the adoption of software-defined networking (SDN) and create a solid foundation for Network Functions Virtualization (NFV). The software is written in Java. OpenFlow is a communications protocol that gives access to the forwarding plane of a network switch or router over the network. The protocol's inventors consider OpenFlow an enabler of Software defined networking (SDN). OpenStack software controls large pools of compute, storage, and networking resources throughout a datacenter, managed through a dashboard or via the OpenStack API. OpenStack works with popular enterprise and open source technologies making it ideal for heterogeneous infrastructure.
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In the middle we see 3GPP will handle a lot of standardization for 5G. ITU will handle spectrum allocation and IMT 2020 requirements for 5G, in a similar way as IMT2000 for 3G and IMT Advanced for 4G. NGMN is the operator community. The main operators come up with requirements for 5G. To the right we have supporting activities for marketing and promoting the technologies as well as IETF that will be very important for the IP protocols also in 5G.
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3
EVOLUTION OF MOBILE BROADBAND It’s a world where Information and Communication Technologies (ICT) are poised to deliver a deep transformation that will shake the very fabric of society. The past few decades of ICT progress have shown significant promise, but this is still only the foundation for what is set to come. We are now at a critical moment – an inflection point – where the next wave of innovation in the form of mobile, broadband, and cloud will be the catalyst for an entirely new economic model. This new age will deliver growth and prosperity based on greater social cohesion and environmental sustainability. The resulting Networked Society holds the potential to truly shape the future and leave a positive legacy for generations to come. To be able to meet the needs and requirements in the Networked Society, it is obvious that the networks needs to increase their performance. Mobile and wireless communications Enablers for the Twenty-twenty Information Society (METIS) project (5G project within EU) have defined the requirements on 5G. The main objective of METIS is to respond to societal challenges beyond 2020 by providing the basis for the all-communicating world and lay the foundation for a future radio access mobile and wireless communications system. This will realize the METIS vision of a future where access to information and sharing of data is available anywhere and anytime to anyone and anything. METIS will develop a concept for the future 5G mobile wireless communications system and will identify the research key building blocks of such a future system. For the Networked Society, 5G has to support extreme performance when it comes to Capacity, data rates, reliability, latency and much more. The METIS overall technical goal provides a system concept that, relative to today, supports: •
1000 times higher mobile data volume per area
•
10 times to 100 times higher number of connected devices
•
10 times to 100 times higher typical user data rate
•
10 years battery life for low power Massive Machine Communication (MMC) devices
•
5 times reduced End-to-End (E2E) latency.
The key challenge is to achieve these objectives at a similar cost and energy consumption as today’s networks.
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In order to understand this change further, it is important to understand what ‘More Communication” actually means. This increased connectivity is actually matched with an even more intense level of communications. This intensity is demonstrated in the 160 petabytes of mobile traffic that traversed mobile networks every month in 2010, to the 2300 monthly petabytes that we currently consume. Traditionally, we used our mobile subscriptions strictly for voice. This evolved in 2010, but voice and data were still nearly similar in size considering global, mobile traffic volumes. The things we do today with our connected devices is so much more diverse than they used to be. Indeed, even a large amount of voice traffic now runs over a data network through VoIP. Even voice has evolved to become data.
3.1
5G Uses Cases One example of Use Case is the Ericsson Connected Vehicle Cloud where we have collaborated with Volvo Cars. Whilst this provides infotainment, apps and communication services, Volvo is also able to open parts of the platform to other players in the automotive industry ecosystem. This means third party service providers such as infotainment providers, road authorities, cities and governments offer Volvo drivers with real-time, actionable information on the move. Connected Vehicle Cloud based on Ericsson’s Multiservice Delivery Platform. Allows drivers, passengers and the car to connect to services available in the cloud, e.g. information, navigation and entertainment apps. Volvo Cars will be able to open parts of the platform to other actors in the ecosystem of the automotive industry Remote Surgery is an example of an Ultra-Reliable Communication use case. An additional example is our work with Maersk Line, the world’s largest ocean carrier. Delivering the largest fleet of cargo ships, Maersk sought a communications platform to provide end-to-end remote management to aid its shipping processes. Through our capabilities, we were able to aid the build-out of the world’s largest floating mobile network, with 350 connected vessels monitoring data in real time, providing the company with information that incrementally contributes to future innovation.
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Transporting 3+ million containers
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End-to-end solution for 350 vessels
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Cut fuel costs and increased the value of Maersk's logistics
•
Reduced CO2 footprint
•
Tighter monitoring of cargo delivery times
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Smart meters record consumption data for utilities such as electricity and water, and communicate it to the billing and revenue management systems. In most cases, installing smart meters is the first step toward creating a smart grid. Ericsson provides a complete range of smart metering services, including planning, deployment, operations and maintenance.
Connected Vehicle
Goods Tracking
Remote Surgery
Smart Grid
Figure 7-6: 5G uses cases examples
3.1.1
Smart Grid Smart Grid: By using ICT to gather and act on information, smart grids give households greater control over their bills and environmental impact, and allow renewable energy sources to be better integrated into the power network. Realtime information enables providers to repair faults as they occur, and even to prevent them happening in the first place. As a global communications leader with extensive multivendor systems integration experience, Ericsson is well placed to partner with utilities as they transform their electricity distribution networks into smart grids A notable example of such social progress is Stockholm Royal Seaport. This project has ambitious plans to create an urban district of 10,000 apartments and 30,000 workspaces that are both climate-positive and free of fossil fuels by 2030. An underlying smart grid system will connect apartments, meters, buildings, vehicles and harbor facilities, powered by an open technology platform. From this platform, new applications can be built for city management and smart street lighting, as well as transport, education and health services.
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Residents will take an active part in this change, contributing to improved traffic planning and government services while adjusting energy and water consumption patterns to reduce peaks in demand. As the developed world continues to account for the majority of environmental waste and consumption, holistic approaches such as these will be necessary to allow citizens to become knowledgeable contributors and collaborators, rather than simply consumers, in a more sustainable ecosystem.
3.2
Virtualization 5G is one of the most anticipated advances in the ICT industry. The introduction of 5G will accelerate transformation in many industry verticals, enabling new use cases in areas such as automation, IoT and big data. With increases in radio performance and the flexibility enabled by network slicing and Network Functions Virtualization (NFV), networks can serve a much broader range of use cases. In 2015, deployments of NFV in core networks began. The first examples of services deployed with NFV were VoLTE, Wi-Fi calling and the expansion of mobile broadband to locations and industries needing high capacity or remote area connectivity. NFV enables faster and more flexible introduction of services, such as distributed mobile broadband, IoT, communication services and enterprise services. It is also a key building block on the path to future 5G deployments. Capacity and throughput remain drivers, with user data consumption continuing to rise with increased use of video. Some specific use cases, like massive IoT and FWA, are likely to be implemented faster, as they can take advantage of the early evolution steps towards 5G. Growth of 5G is linked to growth of the complete ecosystem. Network development and rollout needs to happen at pace with the development of devices, and this will be influenced by access to and licensing of suitable spectrum bands. It is expected that most operators will introduce 5G from 2020, which is closely linked to the timeline for 5G standardization. Early deployments of pre-standard networks are anticipated in selected markets. As of today, there are around 30 operators that have publicly announced 5G introduction plans, with several trials already taking place. Rollout is expected to commence in metropolitan and urban areas, and is forecast to reach around 10 percent population coverage by 2022.
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The Figure below presents an overall of NFV.
› NFV is a first step to 5G core networks. › NFV is currently being deployed in core networks, supporting EPC, IMS, SDM and other functions. Examples of services being deployed include:
Figure 7-7: Network Functions Virtualization
3.2.1
NFV and SDN Network Functions Virtualization technology allows for easier creation and expansion of separate logical nodes and functions for a specified group of traffic and signaling, often referred to as a network slice. In turn, network slicing opens up a new way of achieving in-service software management at the network level For NFV to become really useful, software-defined networking (SDN) technology is required. SDN allows computer-network administrators to manage network services by hiding physical deployments and presenting them as virtualized services. Network services also need to be virtualized in order to reach the same level of flexibility and achieve the advertised simplifications and gains of NFV. Without this, it is not possible to realize many of the promises of NFV in the data center. A logical instantiation of a network is often called a network slice. Network slices are possible to create with both legacy platforms and network functions, but virtualization technologies substantially lower barriers to using the technology, for example through increased flexibility and decreased costs. Currently, management of networks is mostly about managing individual network elements.
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The Figure below presents an overall of NFV and SDN.
Network function virtualization (NFV)
vMME
vEPG
3rd party Apps
Virtualization Layer / PaaS Hardware Layer
Software defined networking (SDN) Controller
Figure 7-8: Network Function Virtualization & Software Defined Networks
One of the major ideas behind NFV is to automate management for the entire network so that complex network-spanning tasks are easier to perform. Integration of different NFV components will still be a complex task for the operator, but on the other hand NFV allows an entire network to be delivered as a pre-integrated network slice. When a network slice covers only a part of the network topology, it is called a sub-network slice, which indicates that network slicing can also be hierarchical. The most commonly used containment of network slices in EPC is the PGW and PCRF in the same slice. Since the PGW selects the PCRF and the Access Point Name (APN) name is used for PGW selection from the MME, the selection mechanisms employed here are often already in use in legacy networks.
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But with network slicing in the data center, they are likely to be even more commonly used. It is also likely that there will be dedicated PGWs and PCRFs for many different deployments, both small and large. Adding a SGW to the previous network slice of a PGW and PCRF and thereby creating another level of network slicing (while still supporting connections from other SGWs to the PGW) is a solution that is of interest when co-located SGWs and PGWs are used. As specified by 3GPP, the SGW selection in the MME can take the selected PGW into account. SDN and NFV will also enable advanced data analytics that can further provide measurability and monitoring to the networks and applications. Lastly, network slicing will allow service providers to use the operator networks as a platform to allow closed groups of users, such as e.g.., the customers of a car manufacturer to transparently roam across multiple operator networks all over the world, and providing performance and maintenance data from an entire fleet of vehicles. Network slicing can create network services optimized for the needs of specific applications, industries, and user groups.
3.2.2
Ericsson HDS The network infrastructure will be designed and built on Ericsson's pioneering Hyperscale Datacenter System, Ericsson HDS 8000. Launched at Mobile World Congress in February 2015, this solution represents a new generation of hyperscale datacenter systems that uses Intel® Rack Scale Architecture for a disaggregated hardware approach that dramatically improves efficiency, utilization, automation and total cost of ownership for virtualized environments. The Figure below shows how Ericsson products for EPC already addresses the path towards 5G and virtualized networks.
CPU RAM NIC Disc
Disaggregated HW › Seamless scalability with efficient life cycle management
Full optical interconnect › Enabling hyperscale
HDS Command center › Advanced automation, orchestration and asset governance
Figure 7-9: Ericsson HDS 8000 HW for EPC - Worlds first using Intel Rackscale architecture
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"Network slicing, based on virtual EPC, is an important part of the technology evolution of 5G, supporting operators with a new, broader set of services. It is important that we work together in the industry on this journey", says Ulf Ewaldsson, CTO, Ericsson. Intel Rack Scale Architecture is a logical architecture that disaggregates compute, storage, and network resources. Introducing the ability to:
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pool these resources
•
simplifying management of compute, storage, and network resources.
•
Enabling the ability to dynamically compose resources based on workload-specific demands
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4
NETWORK ARCHITECTURE
4.1
LTE Reference Architecture This Figure below is to compare to the current LTE architecture.
Figure 7-10: LTE Reference Architecture
The RAN performs all radio interface related functions for terminals in active mode. The current Evolved Packet Core (EPC) provides access to external packet IP networks (anchor) and operator services. The EPC functions are QoS, Authentication, Security Keys, Paging, Idle mode mobility, Terminal context management, packet filtering, etc.
4.1.1
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Interfaces •
Radio and core networks are interconnected via S1 (CP and UP).
•
eNBs are interconnected via X2 (CP and UP).
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4.2
Similar Logical Network The 5G architecture will most likely to some extent reuse the legacy LTE/EPC architecture and CN/RAN split but evolve the interfaces, here called S1* and X2*, and protocols to support the new requirements and flexibility. S1* is an evolved S1 supporting NR/LTE capable UE of Rel-X. A gradual evolution of existing EPC and introduction of new 5G functions will probably take place in parallel. Also, fixed/mobile convergence is expected to be an important part of the evolution towards 5G. 5G Core NW functions
eS1
eS1
eS1
eX2 LTE standalone
NR standalone eX2
eX2
NR / LTE co-located
NGMN
Figure 7-11: Adopting similar logical CN/RAN split as in EPS
4.3
Common Network Architecture As seen earlier: the journey to 5G brings along a number of new use cases. These use cases introduce new requirements that sometimes are conflicting with each other. This calls for some clever thinking. Ericsson introduces Network slicing as a means to deploy multiple logical networks (slices) on a common physical infrastructure.
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The Figure below presents the Common Network Architecture. Network Slicing
Distributed Cloud
Virtualization VNF
Software Defined Networking (SDN)
VNF
VNF VNF
VNF
VNF
Distributed Data Center
Central Data Center
Figure 7-12: Common Network Architecture
The slices are isolated from each other in the control and user planes as well as in the management plane. This allows the slices to be optimized individually for the use cases that they are intended to support. The optimizations of the slices can be in terms of: •
Performance and characteristics (e.g.. a slice supporting a massive amount of sensors may have to be optimized to handle a large amount of devices, but not necessarily support of high data rates and data volumes).
•
Functions (e.g.. a slice supporting traffic control, traffic safety, and autonomous driving cars will need macro scale mobility whereas a deployment of sensors/actuators for an industry automation may be local and not need mobility).
•
Geographical deployment of functions (e.g.. a process automation requiring low delay and high reliability may result in the application as well as the relevant user plane functions being deployed close to sensors/actuators).
The Distributed Cloud technology allows multiple data centers, both central data centers and distributed data centers, to appear as a single (virtual) data center. The data centers are inter-connected by networking capabilities. When deploying functions in such a virtual data center the functions deployed to the data centers where it makes most sense. Combining the Distributed Cloud technology with Virtualization of Network Functions (VNF) allows the functions to be deployed based on the performance (and other) requirements, simplifying the optimization task.
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Separating the control and user plane of the network functions allows for independent scalability of the control and user planes as well as giving additional deployment flexibility. A user plane function supporting a low delay application can be deployed closer to the access, whereas the control plane function can be placed at a more centralized location (assuming less strict delay requirements). (Multiple) SDN (Software Defined Networking) technologies are used to control the multiple purposes of this flexibility. SDN is used to control the WAN transport. To interconnect the data centers in the Distributed Cloud technology as well as inter-connecting the right data center resources with each other. Ericsson already today has products that allow the “above Gi” service chain to be controlled by SDN. When splitting the control and user planes of the network functions, SDN technologies are relevant to control the separated user plane.
4.4
Radio Access 5G wireless access is the overall wireless access solution of the future, fulfilling the needs and requirements for 2020 and beyond. Clearly LTE will be an important part of that future and, consequently, we see the evolution of LTE being a key part of the oveall 5G wireless access solution. More specifically, the evolution of LTE will apply to existing spectrum currently used by LTE, spectrum for which the possibility to introduce 5G capabilities is highly beneficial and, in many cases, vital. However, in parallel to the evolution of LTE, new radio-access technology (denoted NX by Ericsson or NR in 3GPP), not constrained by backwards compatibility, will be developed. Such technology will, at least initially, target new spectrum. A main part of such spectrum will be available at higher frequencies (above 10 GHz). However, there may also be new spectrum at lower frequencies for which new non-backwards-comaptible technology may also apply. In a longer time-perspective, more and more devices supporting new technology is being available, one could of course also envision that the new technology will migrate into spectrum currently used by LTE.
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The Figure below presents an overall of the 5G Radio Access.
› Evolution of existing technology + New radio-access technology
Figure 7-13: 5G Radio Access
The Figure Below presents examples of 5G Radio technology areas. Extension to higher frequencies
Spectrum flexibility Spectrum sharing
Duplex Flexibility
Multi-antenna technologies Beam-forming for coverage
Multi-site coordination
Multi-user MIMO for capacity
• Unlicensed • Shared licensed • Network sharing
Access/backhaul integration
Device-to-device communication
Ultra-lean design
…
Figure 7-14: 5G Radio Technology Areas
Extension to higher frequencies: Complementing lower frequencies for extreme capacity and data rates in dense areas. Spectrum flexibility: •
Unlicensed
•
Shared licensed
•
Network sharing
Multi-antenna technologies: For higher as well as lower frequencies:
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Beam-forming for coverage
•
Multi-user MIMO for capacity
Multi-site coordination: •
Multi-site - transmission/reception
•
Multi-layer - connectivity
Access/backhaul integration •
Same technology for access and backhaul
•
Same spectrum for access and backhaul
Device-to-device communication •
Direct communication
•
Device-based relaying
•
Cooperative devices
Ultra-lean design
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Minimize transmissions not related to user data
•
Separate delivery of user data and system information
•
Higher data rates and enhanced energy efficiency
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4.4.1
Massive MIMO Massive MIMO is an important part of 5G! To enable the capacity, data rate, and coverage needed in the 5G era for both high and low frequencies and for both NR and LTE.
Massive MIMO is an important part of 5G that enables beamformed transmissions!
› Multi-user MIMO › Single-user MIMO Highly focused beam
› Coverage Gain › Capacity Gain › Energy efficiency Figure 7-15: Why 5G Massive MIMO?
Massive means that we have a large amount of antenna elements that enables high directivity beamforming and possibly also high rank transmissions. Massive MIMO highly interesting even without MU-MIMO. Compared to legacy MIMO, Massive MIMO has several benefits: •
Coverage Gain: -
•
Capacity Gain -
•
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Trials have shown 15db gain.
Trials have shown 3 times cell capacity improvement.
Cost Reduction -
Limited antenna size even in 2.6GHz instead of mm-wave.
-
Improved energy efficiency.
•
Beam-centric NR design
•
Self-contained data transmissions
•
Beam mobility – Mobility between beams rather than nodes
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•
•
4.4.2
Single-user MIMO -
One user per time-frequency resource
-
User-specific beamforming to increase SNR
-
Benefits regardless of load
-
Important for coverage
Multi-user MIMO -
Multiple users on the same resource
-
User-specific beamforming to separate users
-
Requires sufficiently high load to show benefits
-
Dynamic switching to SU-MIMO crucial
Ericsson Radio System The Figure below presents the Ericsson Radio System news.
5G Radio
Launched earlier Launched today
5G Transport
Gigabit LTE
LTE Foundation
Vault Radio
Fronthaul on Rail
5G
RAN Evolution
Plug-ins
Baseband
Low Energy Scheduler
• • • • •
5G NR Mid-band
AIR 6468
10 Gbps MINI-LINK
Massive FronthaulMIMO Multi-user on Rail MIMO Latency Reduction Intelligent Connectivity RAN Virtualization
4T / 4R Radios
App Coverage Booster
Gigabit LTE
• • • • •
Indoor MINI-LINK Unit
CAT-M1
4x4 MIMO 256 QAM Carrier Aggregation Lean Carrier License Assisted Access
Shared Carrier
Tower Company Portf olio
5G NR High-band
Bandw idth Notification
Router on Rail
Compact Router
NB-IoT
Dual-band Radio Dot
4T / 4R Dual-band
4T / 4R Low -band
Battery on Rail
Figure 7-16: Ericsson Radio System reaches new heights
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5
SUMMARY The participants should now be able to: p
7. Describe the road to 5G 7.1 Give examples of deployment scenarios in 5G 7.2 Briefly about the evolution of LTE 7.3 Present the Massive MIMO technique 7.4 Describe Cloud solution 7.5 Explain v-RAN ideas 7.6 Present the Ericsson Radio System deployment for 5G Figure 7-17: Summary of Chapter 7
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Index
8 Index
3GPP, 14, 15, 16, 17, 19, 20, 21, 22, 27, 28, 33, 43, 49, 51, 52, 61, 64, 70, 75, 76, 81, 82, 83, 84, 85, 86, 87, 88, 99, 105, 121, 128, 129, 135, 138, 139, 141, 142, 143, 144, 147, 148, 149, 151, 152, 153, 155, 161, 164, 166, 167, 171, 172, 193, 201, 209, 210, 222, 223, 230, 242, 243, 245, 252, 257, 272, 273, 274, 278 ACIR, 278 ACK, 278 ACLR, 278 ACP, 278 ACS, 220, 221, 278 AES, 128, 278 AGW, 278 AIF, 278 AIR, 61, 95, 96, 97, 98, 99, 101, 102, 103, 188, 273, 278 AISG, 278 AM, 278 AMBR, 278 A-MPR, 278 ANR, 182, 199, 210, 211, 212, 213, 214, 223, 224, 275, 278 APAC, 278 API, 148, 244, 278 APN, 156, 251, 278 ARP, 278 ARQ, 24, 60, 278, 280, 283 ARW, 278 AS, 148, 278 A-SBG, 147, 278 ASC, 278 ASD, 278 ASSL, 278 ASSR, 278 BCCH, 278 BCH, 278
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BEM, 278 BM-SC, 168, 278 BS, 278 BSR, 278 BW, 278 C/I, 278 CA, 70, 71, 82, 86, 272, 278 CAPEX, 278 CAZAC, 278 CC, 70, 278 CCCH, 278 CDD, 278 CDF, 278 CDMA, 14, 95, 96, 97, 98, 122, 139, 143, 238, 278 CE, 278 CEPT, 278 CFR, 278 CM, 198, 199, 200, 228, 279 CMAS, 279 CMC, 279 CMDB, 279 CN, 21, 43, 115, 279 COMINF, 279 CO-OP, 279 CORBA, 201, 279 CP, 49, 60, 63, 64, 254, 279 CPC, 279 C-plane, 180, 279 CQI, 65, 74, 279 CRC, 66, 279 C-RNTI, 279 CS, 15, 138, 139, 140, 145, 160, 161, 162, 163, 274, 279 CSCF, 144, 146, 158, 159, 160, 279, 280, 284 CSV, 279 CTR, 279 CW, 279 DCCH, 279 DCH, 26, 279 DCI, 279
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DCN, 279 DFT, 279 DFT-S-OFDM, 279 DHCP, 159, 279 DL-SCH, 78, 279 DNS, 164, 218, 279 DRB, 279 DRX, 279 DSCP, 27, 28, 29, 279 DTCH, 279 DTX, 279 DwPTS, 81, 279 EBS, 40, 279 ECC, 279 ECGI, 279 ECM, 19, 38, 180, 279 E-DCH, 279 EHPLMN, 279 EMEA, 279 EMM, 26, 151, 279 eNB, 22, 23, 45, 49, 50, 58, 59, 60, 87, 167, 168, 172, 179, 180, 182, 219, 221, 222, 231, 279 eNode B, 279 EPC, 16, 18, 21, 22, 26, 31, 32, 33, 40, 45, 47, 48, 49, 52, 58, 143, 157, 163, 164, 251, 252, 253, 254, 255, 272, 274, 275, 279 EPS, 16, 18, 21, 22, 23, 26, 34, 41, 42, 43, 49, 51, 58, 139, 152, 156, 171, 188, 255, 272, 275, 279 E-RAB, 22, 23, 279 ESM, 279 ETSI, 14, 15, 115, 142, 280 ETWS, 280 E-UTRA, 16, 17, 18, 19, 20, 21, 22, 34, 43, 45, 51, 57, 58, 139, 143, 161, 166, 168, 172, 180, 182, 214, 279, 280, 281 E-UTRAN, 16, 17, 18, 20, 21, 22, 34, 43, 45, 51, 57, 58, 139, 143, 161, 166, 168, 172, 180, 182, 214, 279, 280, 281 EV-DO, 17, 280 EVM, 280 FCC, 87, 140, 280 FDD, 14, 15, 17, 24, 58, 70, 72, 77, 78, 79, 84, 90, 92, 106, 109, 110, 111, 112, 123, 171, 172, 273, 280 FDM, 280 FDMA, 14, 24, 280 FEC, 280 FFS, 280 FFT, 280, 281 FM, 202, 228, 280
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FMX, 201, 280 FQDN, 280 FS, 280 FTP, 280 GBR, 156, 280 GCL, 280 GE, 280 GERAN, 21, 43, 51, 139, 140, 161, 162, 172, 184, 213, 214, 280 GGSN, 18, 42, 44, 51, 52, 159, 188, 280 GINR, 280 GMPLS, 280 GNSS, 230, 231, 280 GP, 81, 280 GPRS, 14, 15, 143, 151, 152, 280, 285 GSM, 14, 15, 17, 36, 37, 63, 90, 92, 95, 96, 97, 98, 102, 103, 109, 110, 111, 112, 141, 143, 151, 171, 172, 176, 183, 188, 208, 229, 236, 238, 280 GTP, 49, 50, 51, 52, 280 GTP-C, 51, 52, 280 GTP-U, 49, 50, 51, 52, 280 GUI, 196, 197, 280 GUTI, 280 GW, 18, 22, 23, 45, 52, 167, 168, 280 HA-CS, 280 HARQ, 24, 60, 280 HO, 162, 180, 280 HOM, 16, 280 HPLMN, 52, 280 HRPD, 17, 280 HSDPA, 15, 19, 20, 280 HS-DSCH, 280 HSPA, 15, 16, 17, 78, 101, 110, 111, 138, 139, 236, 238, 280 HSS, 32, 33, 40, 41, 51, 149, 157, 158, 160, 164, 172, 272, 280 HSUPA, 15, 280 HTTP, 151, 280 HW, 38, 41, 205, 225, 228, 229, 252, 275, 280 IASA, 280 ICIC, 84, 221, 222, 275, 280 I-CSCF, 157, 158, 159, 160, 280 ID, 168, 223, 281, 283, 285 IEEE, 123, 142, 281 IETF, 51, 141, 143, 164, 245, 281 IFFT, 281 IFLB, 281 IMEI, 281 IMS, 14, 33, 52, 138, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152,
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153, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 171, 188, 190, 272, 274, 281 IMSI, 281 IMT, 14, 17, 82, 188, 243, 245, 281 IP, 19, 22, 28, 37, 42, 45, 49, 51, 53, 54, 60, 90, 92, 106, 107, 112, 128, 130, 138, 142, 143, 144, 147, 148, 149, 152, 155, 156, 159, 161, 164, 167, 168, 171, 188, 190, 192, 245, 254, 272, 274, 281, 283, 286 IRAT, 176, 183, 184, 274, 281 IS, 14, 281 ISI, 24, 58, 63, 64, 281 ISM, 281 ITU, 14, 17, 82, 123, 236, 241, 245, 281 ITU-R, 281 JSR, 281 KPI, 229, 281 LB, 223, 281 LCID, 281 LCR, 281 LCR-TDD, 281 LDC, 281 LDPC, 281 LED, 217, 228, 229, 281 LTE, 13, 14, 16, 17, 18, 19, 24, 25, 26, 27, 28, 33, 36, 37, 47, 48, 49, 51, 58, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 90, 92, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 109, 110, 111, 112, 121, 122, 123, 126, 128, 129, 137, 138, 139, 140, 141, 144, 148, 157, 159, 161, 163, 164, 166, 167, 168, 170, 171, 172, 175, 176, 177, 181, 182, 183, 184, 185, 187, 188, 194, 198, 199, 200, 205, 206, 208, 209, 210, 214, 218, 221, 223, 224, 225, 226, 228, 229, 230, 231, 232, 236, 238, 241, 242, 243, 254, 255, 257, 260, 272, 273, 274, 275, 280, 281 MAC, 49, 60, 221, 281 MBA, 281 MBMS, 21, 166, 167, 168, 169, 281, 282 MBR, 281 MBSFN, 167, 168, 169, 281 MCCH, 281 MCE, 167, 168, 281 MCH, 281, 282 MCS, 281 MEF, 281 MGC, 147, 161, 281
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MGW, 138, 147, 160, 188, 281 MIB, 281 MIMO, 16, 17, 18, 25, 58, 67, 68, 69, 71, 74, 76, 83, 85, 87, 88, 99, 104, 105, 225, 243, 259, 260, 261, 272, 275, 281, 282, 285 ML-PPP, 281 MM, 43, 281 MME, 18, 32, 33, 34, 35, 36, 37, 38, 39, 41, 43, 44, 45, 46, 49, 50, 51, 52, 59, 128, 161, 162, 167, 168, 172, 177, 181, 182, 230, 251, 252, 272, 281 MMS, 154, 281 MMTel, 33, 48, 138, 139, 141, 143, 144, 145, 148, 150, 153, 154, 161, 272, 274, 281 MOCI, 281 MOM, 281 MOP, 281 MPLS, 282 MPR, 282 MS, 172, 282 MSAP, 282 MTAS, 141, 147, 148, 149, 151, 153, 155, 282 MTCH, 282 MU-MIMO, 260, 282 mUPE, 282 NACK, 282 NAS, 34, 49, 50, 128, 282 NCC, 282 NCL, 282 NCLI, 282 NCS, 282 NE, 282 NEM, 282 NGMN, 223, 241, 245, 282 NGSA, 282 NH, 282 NM, 39, 282 NMS, 202, 223, 228, 282 NMX, 282 NOC, 228, 282 NR, 255, 257, 260, 282 NRT, 282 N-SBG, 147, 282 O&M, 90, 92, 110, 112, 192, 194, 195, 196, 197, 198, 208, 209, 216, 228, 229, 232, 274, 279, 282 OAM, 132, 282 OFDM, 17, 24, 58, 60, 61, 279, 282 OFDMA, 17, 61, 63, 64, 272, 282 OMC, 282
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OOB, 282 OPEX, 209, 220, 222, 223, 232, 282 OSS, 29, 39, 130, 132, 151, 167, 182, 188, 190, 191, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 205, 206, 207, 210, 214, 216, 217, 218, 226, 228, 229, 231, 274, 279, 282 OSS-RC, 29, 39, 182, 188, 190, 191, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 205, 206, 207, 210, 214, 216, 217, 218, 226, 228, 229, 274, 282 OTN, 282 P(N)CCH, 282 P2P, 279, 282 PA, 103, 282 PAPR, 24, 68, 282 PAR, 282 PARC, 282, 285 PBBTE, 282 PBC, 282 PBCH, 282 PBN, 282 PBR, 282 PCC, 144, 282 PCCH, 282 PCEF, 52, 282 PCell, 282 PCFICH, 283 PCH, 26, 283 PCI, 200, 214, 218, 219, 220, 275, 283 PCRF, 32, 40, 52, 251, 252, 272, 283 P-CSCF, 33, 144, 157, 159, 283 PDCCH, 84, 283 PDCP, 49, 60, 221, 283 PDN, 22, 23, 52, 156, 283 PDP, 22, 159, 283 PDSCH, 86, 283 PDU, 283 P-GW, 18, 22, 45, 51, 144, 283 PHICH, 283 PHR, 283 PHS, 283 PHY, 123, 283 PLMN, 52, 144, 152, 159, 177, 279, 280, 283, 284, 286 PM, 205, 206, 207, 228, 283 PMCH, 283 PMI, 283 PMIP, 51, 283 PnP, 283 PoP, 45, 283 PRACH, 283
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PRB, 283 P-RNTI, 283 PS, 15, 16, 87, 138, 139, 151, 161, 162, 283 PSC, 283 P-SCH, 283 PSD, 283 PSK, 283 PSTN, 143, 144, 148, 150, 152, 283 PTT, 283 PUCCH, 283 PUSCH, 283 PWS, 283 QAM, 58, 65, 66, 69, 71, 74, 76, 84, 283 QCI, 27, 28, 156, 283 QoS, 27, 28, 42, 51, 52, 60, 124, 150, 156, 159, 254, 272, 283 QPP, 283 QPSK, 65, 66, 283 RA, 220, 283 RAC, 283 RACH, 283 RAN, 49, 51, 58, 87, 90, 92, 112, 116, 128, 167, 199, 200, 209, 224, 230, 232, 242, 254, 255, 275, 283 RANAP, 49, 283 RA-RNTI, 283 RAT, 49, 140, 176, 177, 183, 184, 209, 223, 224, 283, 285 RB, 68, 74, 75, 283 RBC, 284 RBG, 284 RBS, 27, 28, 29, 89, 95, 96, 97, 98, 99, 100, 104, 105, 106, 130, 132, 167, 188, 194, 196, 197, 199, 202, 203, 205, 206, 207, 209, 210, 213, 214, 216, 217, 218, 219, 220, 221, 225, 228, 229, 273, 274, 275, 278, 284 RET, 284 RF, 61, 62, 63, 68, 77, 79, 80, 86, 102, 121, 226, 272, 284 RFC, 128, 284 RI, 284 RLC, 24, 49, 60, 284 RM, 284 RNC, 18, 58, 284 RNL, 284 RNTI, 279, 283, 284, 285 ROHC, 284 ROP, 207, 231, 284 RPLMN, 284 RRC, 26, 49, 59, 180, 184, 220, 274, 284 RRM, 50, 60, 221, 231, 284
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Index
RRU, 284 RS, 77, 284 RSN, 284 RT, 284 RTCP, 284 RTP, 147, 284 RTSP, 284 RU, 225, 284 RX, 103, 104, 225, 284 S1-MME, 284 S1-U, 49, 51, 284 SAE, 13, 14, 16, 18, 43, 47, 48, 49, 139, 284 SAP, 284 SB, 284 SBC, 284 SBG, 33, 147, 278, 282, 284 SCCH, 284 SCCP, 284 SCell, 284 SCEP, 284 SC-FDMA, 17, 24, 25, 58, 61, 63, 64, 68, 272, 284 SCH, 284 S-CSCF, 157, 158, 159, 160, 284 SCTP, 49, 50, 161, 284 SDF, 22, 23, 284 SDH, 284 SDMA, 284 SDP, 188, 284 SDU, 284 SeGW, 284 SEM, 284 SFN, 284 SFP, 284 S-FTP, 285 SGSN, 18, 34, 35, 36, 37, 38, 39, 43, 44, 51, 52, 159, 188, 272, 285 S-GW, 18, 22, 27, 44, 45, 49, 51, 52, 59, 285 SI, 285 SIB, 176, 285 SINR, 225, 226, 285 SIP, 142, 143, 144, 145, 146, 148, 150, 151, 152, 156, 158, 159, 160, 285 SI-RNTI, 285 SISO, 285 SLA, 285 SLO, 285 SM, 43, 285 SMO, 285 SMRS, 285 SMS, 285
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SN, 284, 285 SNF, 285 SNR, 261, 285 SON, 189, 193, 208, 209, 210, 222, 223, 224, 274, 275, 285 SOX, 285 S-PARC, 285 SPID, 285 SQL, 285 SR, 147, 161, 285 SRB, 285 SRVCC, 138, 147, 161, 162, 274, 285 S-SCH, 285 SSH, 285 SSL, 285 SSLIOP, 285 SU, 261, 285 SU-MIMO, 261, 285 SW, 99, 105, 205, 228, 278, 285 TA, 26, 177, 285 TAS, 285 TAU, 177, 285 TB, 285 TBD, 285 TCP, 207, 285 TDD, 14, 15, 17, 24, 58, 70, 72, 80, 81, 84, 90, 92, 107, 109, 110, 111, 112, 122, 171, 172, 273, 281, 285 TF, 285 TFCI, 285 TFP, 285 TFT, 22, 285 TLA, 285 TLP, 285 TM, 285 TMA, 285 TMO, 285 TNL, 285 TPC, 285 TSP, 40, 41, 286 TTI, 24, 78, 286 TX, 102, 225, 286 UCI, 286 UE, 18, 19, 20, 22, 23, 24, 26, 29, 33, 34, 41, 42, 45, 49, 50, 52, 59, 61, 65, 67, 68, 74, 76, 77, 78, 84, 86, 128, 139, 140, 144, 156, 158, 159, 161, 162, 168, 169, 172, 176, 177, 179, 180, 181, 182, 183, 184, 200, 205, 206, 207, 210, 212, 213, 214, 218, 219, 230, 231, 255, 273, 286 UETR, 286
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UL, 15, 18, 22, 24, 27, 42, 58, 74, 78, 83, 84, 103, 104, 113, 286 UL-SCH, 286 UM, 286 UMTS, 14, 22, 26, 171, 286 UP, 50, 51, 60, 254, 286 UPE, 282, 286 U-plane, 180, 286 UpPTS, 81, 286 URA, 26, 286 UTRA, 15, 280, 286 UTRAN, 286 VoIP, 60, 141, 144, 150, 152, 247, 286 VoLTE, 157
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VPLMN, 52, 286 VRB, 286 WAP, 286 WAPECS, 286 WCDMA, 14, 15, 16, 17, 25, 26, 36, 37, 63, 64, 75, 84, 90, 92, 95, 96, 97, 98, 99, 102, 103, 105, 106, 109, 110, 112, 128, 140, 143, 176, 183, 184, 188, 200, 208, 209, 213, 223, 224, 225, 229, 236, 238, 286 WDM, 286 X2-C, 50, 286 X2-U, 50, 286 XML, 286
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LZT1238828 R15A
Table of Figures
9 Table of Figures
Figure 1-1: Objectives of Chapter 1 .............................................................................................. 11 Figure 1-2: History ........................................................................................................................ 13 Figure 1-3: 3G Evolution ............................................................................................................... 14 Figure 1-4: Mobile System Evolution ............................................................................................. 15 Figure 1-5: LTE 3GPP Rel 8 Targets ............................................................................................ 17 Figure 1-6: EPS Architecture ........................................................................................................ 19 Figure 1-7: EPS Bearer Concept................................................................................................... 20 Figure 1-8: LTE Physical Layer ..................................................................................................... 23 Figure 1-9: Protocol States and Mobility ........................................................................................ 24 Figure 1-10: LTE QoS Implementation .......................................................................................... 26 Figure 1-11: Summary of Chapter 1 .............................................................................................. 28 Figure 2-1: Objectives of Chapter 2 .............................................................................................. 29 Figure 2-2: Evolved Packet Core (EPC) ........................................................................................ 30 Figure 2-3: LTE/EPC/IMS Architecture.......................................................................................... 31 Figure 2-4: Ericsson SGSN-MME Hardware evolution overview ................................................... 32 Figure 2-5: MkVIII hardware .......................................................................................................... 33 Figure 2-6: SGSN-MME MkX ........................................................................................................ 34 Figure 2-7: SGSN-MME MkX Hardware Architecture .................................................................... 35 Figure 2-8: vSGSN-MME .............................................................................................................. 36 Figure 2-9: vSGSN-MME High level architectural.......................................................................... 37 Figure 2-10: PCRF and HSS Nodes.............................................................................................. 38 Figure 2-11: SAPC Classical and Virtual releases......................................................................... 39 Figure 2-12: EPG 16B platform support ........................................................................................ 41 Figure 2-13: Typical Implementation of combined SGSN/MME ..................................................... 42 Figure 2-14: MME Pooling - Moving between pools ...................................................................... 44 Figure 2-15: LTE/EPC Control Plane ............................................................................................ 45 Figure 2-16: LTE/EPC User Plane ................................................................................................ 45 Figure 2-17: Basic EPC architecture – Gx interface .................................................................... 46 Figure 2-18: Basic EPC architecture – Rx interface .................................................................... 46 Figure 2-19: Basic EPC architecture – SGi interface ................................................................... 47 Figure 2-20: Basic MMTel architecture – Gm interface................................................................ 47 Figure 2-21: Evolved IP network solution composition .................................................................. 52 Figure 2-22: EIN solution Attributes .............................................................................................. 53 Figure 2-23: Summary of chapter 2 ............................................................................................... 54 Figure 3-1: Objectives of Chapter 3 .............................................................................................. 57 Figure 3-2: Evolved UTRAN (EUTRAN) ........................................................................................ 59 Figure 3-3: LTE Physical Layer ..................................................................................................... 61 Figure 3-4: LTE Channel Bandwidth ............................................................................................. 62
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Figure 3-5: RF Multipath Propagation ........................................................................................... 63 Figure 3-6: OFDMA/SC-FDMA (Time Domain) ............................................................................. 64 Figure 3-7: Adaptive Modulation ................................................................................................... 65 Figure 3-8: Adaptive Coding ......................................................................................................... 66 Figure 3-9: MIMO Techniques....................................................................................................... 67 Figure 3-10: LTE Scheduling ........................................................................................................ 68 Figure 3-11: LTE Downlink Physical Rates ................................................................................... 69 Figure 3-12: Downlink Throughput ................................................................................................ 70 Figure 3-13: Contiguous Intraband CA .......................................................................................... 70 Figure 3-14: Carrier Aggregation................................................................................................... 71 Figure 3-15: DL 4CC Carrier Aggregation ..................................................................................... 72 Figure 3-16: 4CC DL Carrier Aggregation Extension – FDD/TDD ................................................. 72 Figure 3-17: DL 5CC Carrier Aggregation ..................................................................................... 73 Figure 3-18: LTE Uplink Physical Bit Rates ................................................................................... 74 Figure 3-19: LTE Reference Signals ............................................................................................. 75 Figure 3-20: ERICSSON LEAN CARRIER Applying 5G concepts to today’s 4G LTE ................... 76 Figure 3-21: LTE UE Categories (1/2) ........................................................................................... 77 Figure 3-22: LTE UE Categories (2/2) ........................................................................................... 78 Figure 3-23: LTE FDD Frequency Bands 1/2 ................................................................................ 79 Figure 3-24: LTE FDD Frequency Bands 2/2 ................................................................................ 79 Figure 3-25: LTE TDD Frequency Bands ...................................................................................... 80 Figure 3-26: LTE TDD Operation .................................................................................................. 81 Figure 3-27: LTE Advanced Rel 10 ............................................................................................... 82 Figure 3-28: LTE 3GPP Rel 11 - Further enhancements ............................................................... 83 Figure 3-29: LTE 3GPP Rel 12 - Further enhancements ............................................................... 84 Figure 3-30: Evolution of LTE - 3GPP Release 13 ........................................................................ 85 Figure 3-31: Evolution of LTE Rel14 -3GPP Release 14 ............................................................... 88 Figure 3-32: From Radio Base Station to Radio System ............................................................... 91 Figure 3-33: Ericsson Radio System - Site Types (1/4) ................................................................. 93 Figure 3-34: Ericsson Radio System - Site Types (2/4) ................................................................. 94 Figure 3-35: Ericsson Radio System - Site Types (3/4) ................................................................. 94 Figure 3-36: Ericsson Radio System - Site Types (4/4) ................................................................. 95 Figure 3-37: Ericsson Radio System - RBS 6601 ........................................................................ 100 Figure 3-38: Ericsson Radio System - Radio Nodes ................................................................... 100 Figure 3-39: Ericsson Radio System – AIR ................................................................................. 102 Figure 3-40: Ericsson Radio System - RBS 6402 ........................................................................ 105 Figure 3-41: Ericsson Radio System - RBS 6501 ........................................................................ 106 Figure 3-42: Ericsson Radio System - Radio Dot (1/2) ................................................................ 108 Figure 3-43: Ericsson Radio System - Radio Dot (2/2) ................................................................ 109 Figure 3-44: Ericsson Radio System - Baseband Portfolio .......................................................... 110 Figure 3-45: Ericsson Radio System - Enhanced Baseband Portfolio ......................................... 111 Figure 3-46: Ericsson Radio System – Transport ........................................................................ 114 Figure 3-47: Ericsson Radio System - Backhaul and Fronthaul................................................... 117 Figure 3-48: Ericsson Radio System - Enclosure and Power Modules ........................................ 117 Figure 3-49: Ericsson Radio System - Enclosure Module............................................................ 118 Figure 3-50: Ericsson Radio System - Enclosure 6320 / 6330 / 6340 .......................................... 119 Figure 3-51: Ericsson Radio System - Enclosure 6150 ............................................................... 120 Figure 3-52: Why is Synchronization Needed? ........................................................................... 121 Figure 3-53: LTE: Time/Phase Sync Needs ................................................................................ 122 Figure 3-54: A short introduction to different types of synchronization......................................... 123 Figure 3-55: Sync Alternatives .................................................................................................... 124 Figure 3-56: Synchronization Options ......................................................................................... 125
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Table of Figures
Figure 3-57: Policy and Regulation ............................................................................................. 126 Figure 3-58: Ericsson provides Integrated Security ..................................................................... 127 Figure 3-59: Security Control Landscape, examples ................................................................... 127 Figure 3-60: LTE Ciphering ......................................................................................................... 128 Figure 3-61: Small Cell Auto integration on untrusted backhaul .................................................. 130 Figure 3-62: User Authentication, Authorization and Access Control, Example ........................... 131 Figure 3-63: Digital Certificate and PKI Infrastructure ................................................................. 132 Figure 3-64: Real time Security Event Logging ........................................................................... 133 Figure 3-65: Node Hardening ...................................................................................................... 134 Figure 3-66: Secure Execution Environment ............................................................................... 135 Figure 3-67: Summary of Chapter 3 ............................................................................................ 136 Figure 4-1: Objectives of Chapter 4 ............................................................................................ 137 Figure 4-2: 3GPP Mechanisms for CS Voice/VoLTE Coexistence .............................................. 138 Figure 4-3: CS Fallback - Concept .............................................................................................. 139 Figure 4-4: CS Fallback MSS as Voice Engine for LTE subscribers ............................................ 140 Figure 4-5: IMS – IP Multimedia Subsystem ............................................................................... 142 Figure 4-6: MMTel Basic Service ................................................................................................ 143 Figure 4-7: Volte/CS Architecture................................................................................................ 145 Figure 4-8: IMS and Related Portfolio ......................................................................................... 146 Figure 4-9: LTE/EPC/IMS Architecture example ......................................................................... 157 Figure 4-10: SRVCC (Single Radio Voice Call Continuity) Handover .......................................... 162 Figure 4-11: Wi-Fi Calling Use Case examples ........................................................................... 163 Figure 4-12: Simple add-on to VoLTE Deployments .................................................................. 164 Figure 4-13: Unicast vs Broadcast .............................................................................................. 166 Figure 4-14: eMBMS Use Cases................................................................................................ 166 Figure 4-15: End to end Solution................................................................................................. 167 Figure 4-16: eMBMS Areas and Services ................................................................................... 168 Figure 4-17: Ericsson Mobile positioning System ........................................................................ 170 Figure 4-18: Positioning Methods for LTE ................................................................................... 171 Figure 4-19: Summary of Chapter 4 ............................................................................................ 173 Figure 5-1: Objectives of Chapter 5 ............................................................................................ 175 Figure 5-2: LTE Mobility Introduction........................................................................................... 176 Figure 5-3: UEs in Idle Mode ...................................................................................................... 177 Figure 5-4: Periodic Tracking area update .................................................................................. 178 Figure 5-5: Connected mode mobility.......................................................................................... 179 Figure 5-6: Event Triggered Measurement Reporting ................................................................. 180 Figure 5-7: Mobility in RRC_CONNECTED mode ....................................................................... 180 Figure 5-8: Intra-Freq. LTE Handover ......................................................................................... 181 Figure 5-9: Intra-LTE Handovers................................................................................................. 182 Figure 5-10: Poor Coverage Handling ......................................................................................... 183 Figure 5-11: IF / IRAT Mobility .................................................................................................... 184 Figure 5-12: Seamless mobility between LTE and Wi-Fi ............................................................. 185 Figure 5-13: Summary of Chapter 5 ............................................................................................ 186 Figure 6-1: Objectives of Chapter 6 ............................................................................................ 187 Figure 6-2: Ericsson Mobile OSS Portfolio .................................................................................. 188 Figure 6-3: Today’s Management Network.................................................................................. 190 Figure 6-4: Future Management Network .................................................................................... 191 Figure 6-5: Mul Interface ............................................................................................................. 192 Figure 6-6: O&M Areas ............................................................................................................... 192 Figure 6-7: OSS-RC: OSS Explorer ............................................................................................ 194 Figure 6-8: Ericsson Network Manager (ENM): OSS Applications .............................................. 195
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Figure 6-9: Element Manager GUI .............................................................................................. 196 Figure 6-10: Pico (and Micro) RBS environment ......................................................................... 197 Figure 6-11: Configuration Management ..................................................................................... 198 Figure 6-12: Fault Management Functionality ............................................................................. 202 Figure 6-13: Security Management ............................................................................................. 203 Figure 6-14: Software Management ............................................................................................ 204 Figure 6-15: Performance Management Applications.................................................................. 205 Figure 6-16: Smart Simplicity - SON ........................................................................................... 208 Figure 6-17: Why SON? Self Organization Network .................................................................... 209 Figure 6-18: SON Function Examples ......................................................................................... 210 Figure 6-19: Automated Neighbor Relations ............................................................................... 211 Figure 6-20: ANR Operation ....................................................................................................... 212 Figure 6-21: Automatic Neighbor Relations ................................................................................. 213 Figure 6-22: Automated mobility Optimization ............................................................................. 215 Figure 6-23: Autointegration of RBS (macro) .............................................................................. 216 Figure 6-24: Auto-Integration Using a smartphone – Site Perspective ........................................ 217 Figure 6-25: Pico/micro RBS Auto-integration ............................................................................. 217 Figure 6-26: Automatic PCI Assignment ..................................................................................... 218 Figure 6-27: PCI Conflict Detection ............................................................................................. 219 Figure 6-28: Advanced Cell Supervision Overview...................................................................... 220 Figure 6-29: Inter Cell Interference Coordination - ICIC .............................................................. 221 Figure 6-30: SON Optimization Manager .................................................................................... 222 Figure 6-31: Find Faulty Antenna ................................................................................................ 227 Figure 6-32: Minimization of Drive Tests - MDT .......................................................................... 231 Figure 6-33: Summary of Chapter 6 ............................................................................................ 233 Figure 7-1: Objectives of Chapter 7 ............................................................................................ 235 Figure 7-2: Evolution of Mobile Broadband ................................................................................. 237 Figure 7-3: Mobile subscriptions by region (billion)...................................................................... 237 Figure 7-4: 5G Standardization ................................................................................................... 242 Figure 7-5: 5G Standardization Forums ...................................................................................... 244 Figure 7-6: 5G uses cases examples .......................................................................................... 248 Figure 7-7: Network Functions Virtualization ............................................................................... 250 Figure 7-8: Network Function Virtualization & Software Defined Networks .................................. 251 Figure 7-9: Ericsson HDS 8000 HW for EPC - Worlds first using Intel Rackscale architecture .... 252 Figure 7-10: LTE Reference Architecture .................................................................................... 254 Figure 7-11: Adopting similar logical CN/RAN split as in EPS ..................................................... 255 Figure 7-12: Common Network Architecture ............................................................................... 256 Figure 7-13: 5G Radio Access .................................................................................................... 258 Figure 7-14: 5G Radio Technology Areas ................................................................................... 258 Figure 7-15: Why 5G Massive MIMO? ........................................................................................ 260 Figure 7-16: Ericsson Radio System reaches new heights.......................................................... 261 Figure 7-17: Summary of Chapter 7 ............................................................................................ 262
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Abbreviations and Acronyms
10 Abbreviations and Acronyms
3GPP ACIR ACK ACLR ACP ACS AES AGW AIF AIR AISG AM AMBR A-MPR ANR APAC API APN ARP ARQ ARW AS AS A-SBG ASC ASD ASSL ASSR BCCH BCH BEM BM-SC BS BSR BW C/I CA CAPEX CAZAC
LZT1238828 R15A
3rd Generation Partnership Project Adjacent Channel Interference Ratio Acknowledgement Adjacent Channel Leakage Ratio Automatic Cell Planning Adjacent Channel Selectivity Advanced Encryption Standard Access Gateway Auto-Integration Function Automated Integration of RBS Antenna Interface Standards Group Acknowledged Mode Aggregate Maximum Bit Rate Additional Maximum Power Reduction Automated Neighbor Relation Asia Pacific Application Programming Interface Access Point Name Allocation and Retention Priority Automatic Repeat Request Add RBS Wizard Access Stratum Application Server Access SBG Antenna System Controller Automatic SW Download Adjacent Subcarrier Set Leakage Adjacent Subcarrier Set Rejection Broadcast Control Channel Broadcast Channel Block Edge Masks Broadcast-Multicast Service Center Base Station Buffer Status Report Bandwidth Carrier-to-Interference Power Ratio Certificate Authority Capital Expenditure Constant Amplitude Zero Auto-Correlation
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LTE/SAE System Overview CA CC CCCH CDD CDF CDMA CE CEPT CFR CM CMAS CMC CMDB CN COMINF CO-OP CORBA CP CP CPC C-plane CQI CRC C-RNTI CS CSCF CSV CTR CW CW DCCH DCH DCI DCN DFT DFT-S-OFDM DHCP DL-SCH DNS DRB DRX DSCP DTCH DTX DwPTS EBS ECC ECGI ECM E-DCH EHPLMN
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Carrier Aggregation Component Carrier Common Control Channel Cyclic Delay Diversity Cumulative Distribution Function Code Division Multiple Access Carrier Ethernet The European Conference of Postal and Telecommunications Administrations Channel Feedback Report Configuration Management Commercial Mobile Alert System Connection Mobility Control Configuration Management Data Base Core Network Common O&M Infrastructure Cooperative Open-OSS Project (interface also called Itf-P2P) Common Object Request Broker Architecture Cyclic Prefix Control Plane Continous Packet Connectivity Control Plane Channel Quality Indicator Cyclic Redundancy Check Cell RNTI Circuit Switched Call Session Control Function Comma-Separated Values Cell TRace Codeword Continuous-wave Dedicated Control Channel Dedicated Channel Downlink Control Information Data Communication Network Discrete Fourier Transform DFT Spread OFDM Dynamic Host Configuration Protocol Downlink Shared Channel Domain Name Service Data Radio Bearer Discontinuous Reception Differentiated Services Code Point Dedicated Traffic Channel Discontinuous Transmission Downlink Pilot Time Slot Event Based Statistics Electronic Communications Committee E-UTRAN Cell Global Identifier EPS Connection Management Enhanced DCH Equivalent Home PLMN
© Ericsson AB 2017
LZT1238828 R15A
Abbreviations and Acronyms
EMEA EMM eNB eNode B EPC EPC EPS E-RAB ESM ETSI ETWS E-UTRA E-UTRAN EV-DO EVM FCC FDD FDM FDMA FEC FFS FFT FM FMX FQDN FS FTP GBR GCL GE GERAN GINR GGSN GMPLS GNSS GP GPRS GSM GTP GTP-C GTP-U GUI GUTI GW HA-CS HARQ HO HOM HPLMN HRPD HSDPA
LZT1238828 R15A
Europe, Middle East and Africa EPS Mobility Management E-UTRAN NodeB E-UTRAN NodeB Ericsson Policy Control Evolved Packet Core Evolved Packet System (E-UTRAN and EPC) E-UTRAN Radio Access Bearer EPS Subscription Manager European Telecommunications Standards Institute Earth Quake and Tsunami Warning System Evolved UTRA Evolved UTRAN, used as synonym for LTE in the document. Evolution - Data Optimized Error Vector Magnitude Federal Communications Commission Frequency Division Duplex Frequency Division Multiplexing Frequency Division Multiple Access Forward Error Correction For Further Study Fast Fourier Transform Fault Management Fault Management Expert Fully Qualified Domain Name Frame Structure File Transfer Protocol Guaranteed Bit Rate Generalized Chirp Like Gigabit Ethernet GSM EDGE Radio Access Network Gain to Interference and Noise Ratio Gateway GPRS Support Node Generalized Multi-Protocol Label Switching Global Navigation Satellite System Guard Period General Packet Radio Service Global System for Mobile communication GPRS Tunneling Protocol GTP Control GTP User Data Tunneling Graphical user Interface Globally Unique Temporary Identifier Gateway High Availability Cluster Solution Hybrid ARQ Handover Higher Order Modulation Home PLMN High Rate Packet Data High Speed Downlink Packet Access
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LTE/SAE System Overview HS-DSCH HSPA HSS HSUPA HTTP HW IASA ICIC I-CSCF ID IEEE IETF IFFT IFLB IMEI IMT IMS IMSI IMT IP IRAT IS ISI ISM ITU ITU-R JSR KPI LB LCID LCR LCR-TDD LDC LDPC LED LTE MAC MBA MBMS MBR MBSFN MCCH MCE MCH MCS MEF MGC MGW MIB MIB MIMO
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High Speed Downlink Shared Channel High Speed Packet Access Home Subscriber Server High Speed Uplink Packet Access Hypertext Transfer Protocol Hardware Inter-Access Anchor Inter-Cell Interference Coordination Interrogating CSCF Identifier Institute of Electrical and Electronics Engineers Internet Engineering Task Force Inverse FFT Interfrequency Load Balancing International Mobile Equipment Identity IP Multimedia Telephony IP Multimedia subsystem Individual Mobile Subscriber Identity International Mobile Telecommunications Internet Protocol Inter Radio Access Technology Integrated Site Inter Symbol Interference IMS Subscription Manager International Telecommunications Union ITU Radio communication Sector Java Specification Request Key Performance Indicator Load Balancing Logical Channel ID Low Chip Rate Low Chip Rate TDD Linear Dispersion Code Low-Density Parity-check Code Light Emitting Diode Long Term Evolution, used as synonym for E-UTRAN in the document. Medium Access Control Management Based Activation Multimedia Broadcast Multicast Service Maximum Bit Rate Multicast Broadcast Single Frequency Network Multicast Control Channel Multi-cell/multicast Coordination Entity Multicast Channel Modulation and Coding Scheme Mobile Entertainment Forum Media Gateway Controller Media Gateway Master Information Block Management Information Base Multiple Input Multiple Output
© Ericsson AB 2017
LZT1238828 R15A
Abbreviations and Acronyms
ML-PPP MM MM MME MMS MMTel MOCI MOM MOP MPLS MPR MS MSAP MTAS MTCH MU-MIMO mUPE NACK NAS NCC NCL NCLI NCS NE NEM NGMN NGSA NH NM NMS NMX NOC NR NRT N-SBG O&M OAM OFDM OFDMA OMC OOB OPEX OSS OSS-RC OTN P(N)CCH P2P PA PAPR PAR PARC
LZT1238828 R15A
Multilink point to point protocol Multi Mediation Mobility Management Mobility Management Entity Multimedia Messaging Service Managed Objects interface (MOCI) Multi Media Telephony Managed Object Configuration Interface Managed Object Model Maximum Output Power Multiple Protocol Label Switching Maximum Power Reduction Management Services MCH Subframe Allocation Pattern Multimedia Telephony Application Server Multicast Traffic Channel Multiple User-MIMO MBMS UPE Negative Acknowledgement Non-Access Stratum Network Color Code Neighbour Cell List Node Command Line Interface Neighbouring Cell Support Network Element Network Element Manager Next Generation Mobile Networks Next Generation Service Assurance Next Hop Key Network Management Network Management System Network level deployment of expert rules Network Operations Center Neighbor cell Relation Non Real Time Network SBG Operation and Maintenance Operations Administration and Management Orthogonal Frequency Division Multiplexing Orthogonal Frequency Division Multiple Access Operation and Maintenance Center Out Of Band Operating Expenditures Operation and Support System Operation and Support System Radio and Core Operator Terminal Network Paging (and Notification) Control Channel Peer-to-Peer Power Amplifier Peak to Average Power Ratio Peak to Average Ratio Per Antenna Rate Control
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LTE/SAE System Overview PBBTE PBC PBCH PBN PBR PCC PCCH PCEF PCell PCFICH PCH PCI PCRF P-CSCF PDCCH PDCP PDN PDP PDSCH PDU P-GW PHICH PHR PHS PHY PLMN PM PMCH PMI PMIP PnP PoP PRACH PRB P-RNTI PS PSC P-SCH PSD PSK PSTN PTT PUCCH PUSCH PWS QAM QCI QoS QPP QPSK RA
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Provider Backbone Bridge Traffic Engineering Power and Battery Cabinet Physical Broadcast CHannel Packet Backbone Network Prioritized Bit Rate Policy Charging Control Paging Control Channel Policy Charging Enforcement Function Primary Cell Physical Control Format Indicator CHannel Paging Channel Physical Cell ID Policy Control and Charging Rules Function Proxy - Call Session Control Function Physical Downlink Control CHannel Packet Data Convergence Protocol Packet Data Network Packet Data Protocol Physical Downlink Shared CHannel Protocol Data Unit PDN Gateway Physical Hybrid ARQ Indicator CHannel Power Headroom Report Personal Handy-phone System Physical layer Public Land Mobile Network Performance Management Physical Multicast CHannel Precoding Matrix Indicator Proxy Mobile IP Plug and Play Point of Presence Physical Random Access CHannel Physical Resource Block Paging RNTI Packet Switched Packet Scheduling Primary Synchronization Channel Power Spectrum Density Pre-Shared Keys Public Switched Telephone Network Push to Talk Physical Uplink Control CHannel Physical Uplink Shared Channel Public Warning System Quadrature Amplitude Modulation QoS Class Identifier Quality of Service Quadrature Permutation Polynomial Quadrature Phase Shift Keying Random Access
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LZT1238828 R15A
Abbreviations and Acronyms
RA RAC RACH RAN RANAP RA-RNTI RAT RB RB RBC RBG RBS RET RF RFC RI RLC RM RNC RNL RNTI ROHC ROP RPLMN RRC RRM RRU RS RS RSN RT RTCP RTP RTSP RU RX S1-MME S1-U SAE SAP SB SBC SBG SCCH SCCP SCell SCEP SC-FDMA SCH S-CSCF SCTP
LZT1238828 R15A
Registration Authority Radio Admission Control Random Access Channel Radio Access Network RAN Application Part Random Access RNTI Radio Access Technology Radio Bearer Resource Block Radio Bearer Control Radio Bearer Group Radio Base Station Remote Electrical Tilt Radio Frequency Request For Comment Rank Indicator Radio Link Control Rate Matching Radio Network Controller Radio Network Layer Radio Network Temporary Identifier Robust Header Compression Recording Output Periods Registered PLMN Radio Resource Control Radio Resource Management Radio Remote Unit Reference Symbols Reference Signal Retransmission SN Real Time RTP Control Protocol Real Time Transport Protocol Real Time Streaming Protocol Resource Unit Receiver S1 for the control plane S1 for the user plane System Architecture Evolution Service Access Point Scheduling Block Session Border Controller Session Border Gateway Shared Control Channel Signaling Connection Control Part Secondary Cell Simple Certificate Enrolment Protocol Single Carrier – Frequency Division Multiple Access Synchronization Channel Serving CSCF Streaming Control Transmission Protocol
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LTE/SAE System Overview SDF SDH SDMA SDP SDU SeGW SEM SFN SFP S-FTP SGSN S-GW SI SIB SINR SIP SI-RNTI SISO SLA SLO SM SMO SMRS SMS SN SNF SNR SON SOX S-PARC SPID SQL SR SRB SRVCC S-SCH SSH SSL SSLIOP SU SU-MIMO SW TA TAS TAU TB TBD TCP TDD TF TFCI
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Service Data Flow Synchronous Digital Hierarchy Spatial Division Multiple Access Session Description Protocol Service Data Unit Security Gateway Spectrum Emission Mask System Frame Number Small Form factor Pluggable Secure File transfer protocol Serving GPRS Support Node Serving Gateway System Information System Information Block Signal to Interference and Noise Ratio Session Initiation Protocol System Info RNTI Single Input Single Output Service Level Agreement Service Level Objectives Session Management Software Manager Organizer Software Management Repository Short Message Service Sequence Number Service Network Framework Signal to Noise Ratio Self Organizing Networks Simple Outline XML Selective PARC Subscriber Profile ID for RAT/Frequency Priority Structured Query Language Scheduling Request Signaling Radio Bearer Single Radio Voice Call Continuity Secondary Synchronization Channel Secure Shell Secure Sockets Layer IIOP over SSL Scheduling Unit Single-User MIMO Soft Ware Tracking Area Telephony Application Server Tracking Area Update Transport Block To Be Decided Transmission Control Protocol Time Division Duplex Transport Format Transport Format Combination Indicator
© Ericsson AB 2017
LZT1238828 R15A
Abbreviations and Acronyms
TFP TFT TLA TLP TM TMA TMO TNL TPC TSP TTI TX UCI UE UETR UL UL-SCH UM UMTS UP UPE U-plane UpPTS URA UTRA UTRAN VoIP VPLMN VRB WAP WAPECS WCDMA WDM X2-C X2-U XML
LZT1238828 R15A
Traffic Forwarding Policy Traffic Flow Template Three Letter Acronym TEMS LinkPlanner Transparent Mode Tower Mounted Amplifier T-Mobile International AG Transport Network Layer Transmit Power Control Ericsson Telecom Server Platform Transmission Time Interval Transmitter Uplink Control Information User Equipment UE TRace Uplink Uplink Shared Channel Unacknowledged Mode Universal Mobile Telecommunication System User Plane User Plane Entity User plane Uplink Pilot Time Slot UTRAN Routing Area UMTS Terrestrial Radio Access UMTS Terrestrial Radio Access Network Voice over IP Visited PLMN Virtual Resource Block Wireless Access Protocol Wireless Access Policy for Electronic Communications Services Wideband Code Division Multiple Access Wavelength Division Multiplexing X2-Control plane X2-User plane Extensible Markup Language
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