AN INTRODUCTIONTO LTE

AN INTRODUCTIONTO LTELTE, LTE-ADVANCED, SAE, VoLTEAND 4G MOBILE COMMUNICATIONS

Second Edition

Christopher Cox

Director, Chris Cox Communications Ltd, UK

This edition first published 2014© 2014 John Wiley & Sons, Ltd

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Library of Congress Cataloging-in-Publication Data

Cox, Christopher (Christopher Ian), 1965-An introduction to LTE LTE, LTE-advanced, SAE, VoLTE and 4G mobile communications / Christopher Cox.

pages cmIncludes index.ISBN 978-1-118-81803-9 (cloth)1. Long-Term Evolution (Telecommunications) 2. Mobile communication systems – Standards. I. Title.TK5103.48325.C693 2014621.3845′6 – dc23

2014007432

A catalogue record for this book is available from the British Library.

ISBN:9781118818039

Set in 10/12 Times by Laserwords Private Limited, Chennai, India

To my nieces, Louise and Zoe

Contents

Preface xxi

Acknowledgements xxiii

List of Abbreviations xxv

1 Introduction 11.1 Architectural Review of UMTS and GSM 1

1.1.1 High-Level Architecture 11.1.2 Architecture of the Radio Access Network 21.1.3 Architecture of the Core Network 41.1.4 Communication Protocols 5

1.2 History of Mobile Telecommunication Systems 61.2.1 From 1G to 3G 61.2.2 Third Generation Systems 7

1.3 The Need for LTE 81.3.1 The Growth of Mobile Data 81.3.2 Capacity of a Mobile Telecommunication System 91.3.3 Increasing the System Capacity 101.3.4 Additional Motivations 11

1.4 From UMTS to LTE 111.4.1 High-Level Architecture of LTE 111.4.2 Long-Term Evolution 121.4.3 System Architecture Evolution 131.4.4 LTE Voice Calls 141.4.5 The Growth of LTE 15

1.5 From LTE to LTE-Advanced 161.5.1 The ITU Requirements for 4G 161.5.2 Requirements of LTE-Advanced 161.5.3 4G Communication Systems 161.5.4 The Meaning of 4G 17

1.6 The 3GPP Specifications for LTE 17References 19

2 System Architecture Evolution 212.1 High-Level Architecture of LTE 21

viii Contents

2.2 User Equipment 212.2.1 Architecture of the UE 212.2.2 UE Capabilities 22

2.3 Evolved UMTS Terrestrial Radio Access Network 232.3.1 Architecture of the E-UTRAN 232.3.2 Transport Network 242.3.3 Small Cells and the Home eNB 25

2.4 Evolved Packet Core 252.4.1 Architecture of the EPC 252.4.2 Roaming Architecture 272.4.3 Network Areas 282.4.4 Numbering, Addressing and Identification 28

2.5 Communication Protocols 302.5.1 Protocol Model 302.5.2 Air Interface Transport Protocols 312.5.3 Fixed Network Transport Protocols 312.5.4 User Plane Protocols 322.5.5 Signalling Protocols 33

2.6 Example Signalling Flows 342.6.1 Access Stratum Signalling 342.6.2 Non-Access Stratum Signalling 35

2.7 Bearer Management 362.7.1 The EPS Bearer 362.7.2 Default and Dedicated Bearers 372.7.3 Bearer Implementation Using GTP 382.7.4 Bearer Implementation Using GRE and PMIP 392.7.5 Signalling Radio Bearers 39

2.8 State Diagrams 402.8.1 EPS Mobility Management 402.8.2 EPS Connection Management 402.8.3 Radio Resource Control 41

2.9 Spectrum Allocation 43References 45

3 Digital Wireless Communications 493.1 Radio Transmission and Reception 49

3.1.1 Carrier Signal 493.1.2 Modulation Techniques 503.1.3 The Modulation Process 513.1.4 The Demodulation Process 533.1.5 Channel Estimation 553.1.6 Bandwidth of the Modulated Signal 55

3.2 Radio Transmission in a Mobile Cellular Network 563.2.1 Multiple Access Techniques 563.2.2 FDD and TDD Modes 56

3.3 Impairments to the Received Signal 58

Contents ix

3.3.1 Propagation Loss 583.3.2 Noise and Interference 583.3.3 Multipath and Fading 583.3.4 Inter-symbol Interference 60

3.4 Error Management 613.4.1 Forward Error Correction 613.4.2 Automatic Repeat Request 623.4.3 Hybrid ARQ 63References 65

4 Orthogonal Frequency Division Multiple Access 674.1 Principles of OFDMA 67

4.1.1 Sub-carriers 674.1.2 The OFDM Transmitter 684.1.3 The OFDM Receiver 704.1.4 The Fast Fourier Transform 724.1.5 Block Diagram of OFDMA 724.1.6 Details of the Fourier Transform 73

4.2 Benefits and Additional Features of OFDMA 754.2.1 Orthogonal Sub-carriers 754.2.2 Choice of Sub-carrier Spacing 754.2.3 Frequency-Specific Scheduling 774.2.4 Reduction of Inter-symbol Interference 784.2.5 Cyclic Prefix Insertion 794.2.6 Choice of Symbol Duration 804.2.7 Fractional Frequency Re-use 81

4.3 Single Carrier Frequency Division Multiple Access 824.3.1 Power Variations From OFDMA 824.3.2 Block Diagram of SC-FDMA 83References 85

5 Multiple Antenna Techniques 875.1 Diversity Processing 87

5.1.1 Receive Diversity 875.1.2 Closed Loop Transmit Diversity 885.1.3 Open Loop Transmit Diversity 89

5.2 Spatial Multiplexing 905.2.1 Principles of Operation 905.2.2 Open Loop Spatial Multiplexing 925.2.3 Closed Loop Spatial Multiplexing 945.2.4 Matrix Representation 965.2.5 Implementation Issues 995.2.6 Multiple User MIMO 99

5.3 Beamforming 1015.3.1 Principles of Operation 1015.3.2 Beam Steering 102

x Contents

5.3.3 Downlink Multiple User MIMO Revisited 103References 104

6 Architecture of the LTE Air Interface 1056.1 Air Interface Protocol Stack 1056.2 Logical, Transport and Physical Channels 107

6.2.1 Logical Channels 1076.2.2 Transport Channels 1076.2.3 Physical Data Channels 1086.2.4 Control Information 1096.2.5 Physical Control Channels 1106.2.6 Physical Signals 1116.2.7 Information Flows 111

6.3 The Resource Grid 1116.3.1 Slot Structure 1116.3.2 Frame Structure 1136.3.3 Uplink Timing Advance 1156.3.4 Resource Grid Structure 1166.3.5 Bandwidth Options 117

6.4 Multiple Antenna Transmission 1186.4.1 Downlink Antenna Ports 1186.4.2 Downlink Transmission Modes 119

6.5 Resource Element Mapping 1196.5.1 Downlink Resource Element Mapping 1196.5.2 Uplink Resource Element Mapping 121References 123

7 Cell Acquisition 1257.1 Acquisition Procedure 1257.2 Synchronization Signals 126

7.2.1 Physical Cell Identity 1267.2.2 Primary Synchronization Signal 1277.2.3 Secondary Synchronization Signal 128

7.3 Downlink Reference Signals 1287.4 Physical Broadcast Channel 1297.5 Physical Control Format Indicator Channel 1307.6 System Information 131

7.6.1 Organization of the System Information 1317.6.2 Transmission and Reception of the System Information 133

7.7 Procedures after Acquisition 133References 134

8 Data Transmission and Reception 1358.1 Data Transmission Procedures 135

8.1.1 Downlink Transmission and Reception 1358.1.2 Uplink Transmission and Reception 137

Contents xi

8.1.3 Semi Persistent Scheduling 1398.2 Transmission of Scheduling Messages on the PDCCH 139

8.2.1 Downlink Control Information 1398.2.2 Resource Allocation 1408.2.3 Example: DCI Format 1 1418.2.4 Radio Network Temporary Identifiers 1428.2.5 Transmission and Reception of the PDCCH 143

8.3 Data Transmission on the PDSCH and PUSCH 1448.3.1 Transport Channel Processing 1448.3.2 Physical Channel Processing 146

8.4 Transmission of Hybrid ARQ Indicators on the PHICH 1488.4.1 Introduction 1488.4.2 Resource Element Mapping of the PHICH 1488.4.3 Physical Channel Processing of the PHICH 149

8.5 Uplink Control Information 1498.5.1 Hybrid ARQ Acknowledgements 1498.5.2 Channel Quality Indicator 1508.5.3 Rank Indication 1518.5.4 Precoding Matrix Indicator 1518.5.5 Channel State Reporting Mechanisms 1518.5.6 Scheduling Requests 152

8.6 Transmission of Uplink Control Information on the PUCCH 1538.6.1 PUCCH Formats 1538.6.2 PUCCH Resources 1548.6.3 Physical Channel Processing of the PUCCH 155

8.7 Uplink Reference Signals 1558.7.1 Demodulation Reference Signal 1558.7.2 Sounding Reference Signal 156

8.8 Power Control 1578.8.1 Uplink Power Calculation 1578.8.2 Uplink Power Control Commands 1588.8.3 Downlink Power Control 159

8.9 Discontinuous Reception 1598.9.1 Discontinuous Reception and Paging in RRC_IDLE 1598.9.2 Discontinuous Reception in RRC_CONNECTED 159References 161

9 Random Access 1639.1 Transmission of Random Access Preambles on the PRACH 163

9.1.1 Resource Element Mapping 1639.1.2 Preamble Sequence Generation 1659.1.3 Signal Transmission 165

9.2 Non-Contention-Based Procedure 1669.3 Contention-Based Procedure 167

References 169

xii Contents

10 Air Interface Layer 2 17110.1 Medium Access Control Protocol 171

10.1.1 Protocol Architecture 17110.1.2 Timing Advance Commands 17310.1.3 Buffer Status Reporting 17310.1.4 Power Headroom Reporting 17310.1.5 Multiplexing and De-multiplexing 17410.1.6 Logical Channel Prioritization 17410.1.7 Scheduling of Transmissions on the Air Interface 175

10.2 Radio Link Control Protocol 17610.2.1 Protocol Architecture 17610.2.2 Transparent Mode 17710.2.3 Unacknowledged Mode 17710.2.4 Acknowledged Mode 178

10.3 Packet Data Convergence Protocol 18010.3.1 Protocol Architecture 18010.3.2 Header Compression 18010.3.3 Prevention of Packet Loss during Handover 182References 183

11 Power-On and Power-Off Procedures 18511.1 Power-On Sequence 18511.2 Network and Cell Selection 187

11.2.1 Network Selection 18711.2.2 Closed Subscriber Group Selection 18711.2.3 Cell Selection 188

11.3 RRC Connection Establishment 18911.3.1 Basic Procedure 18911.3.2 Relationship with Other Procedures 190

11.4 Attach Procedure 19111.4.1 IP Address Allocation 19111.4.2 Overview of the Attach Procedure 19211.4.3 Attach Request 19211.4.4 Identification and Security Procedures 19411.4.5 Location Update 19511.4.6 Default Bearer Creation 19611.4.7 Attach Accept 19711.4.8 Default Bearer Update 198

11.5 Detach Procedure 199References 200

12 Security Procedures 20312.1 Network Access Security 203

12.1.1 Security Architecture 20312.1.2 Key Hierarchy 20412.1.3 Authentication and Key Agreement 205

Contents xiii

12.1.4 Security Activation 20712.1.5 Ciphering 20812.1.6 Integrity Protection 209

12.2 Network Domain Security 21012.2.1 Security Protocols 21012.2.2 Security in the Evolved Packet Core 21012.2.3 Security in the Radio Access Network 211References 212

13 Quality of Service, Policy and Charging 21513.1 Policy and Charging Control 215

13.1.1 Quality of Service Parameters 21513.1.2 Service Data Flows 21713.1.3 Charging Parameters 21813.1.4 Policy and Charging Control Rules 219

13.2 Policy and Charging Control Architecture 21913.2.1 Basic PCC Architecture 21913.2.2 Local Breakout Architecture 22013.2.3 Architecture Using a PMIP Based S5/S8 22013.2.4 Software Protocols 221

13.3 Session Management Procedures 22213.3.1 IP-CAN Session Establishment 22213.3.2 Mobile Originated SDF Establishment 22313.3.3 Server Originated SDF Establishment 22413.3.4 Dedicated Bearer Establishment 22513.3.5 PDN Connectivity Establishment 22613.3.6 Other Session Management Procedures 228

13.4 Data Transport in the Evolved Packet Core 22813.4.1 Packet Handling at the PDN Gateway 22813.4.2 Data Transport Using GTP 22913.4.3 Differentiated Services 23013.4.4 Multiprotocol Label Switching 23113.4.5 Data Transport Using GRE and PMIP 231

13.5 Charging and Billing 23113.5.1 High Level Architecture 23113.5.2 Offline Charging 23213.5.3 Online Charging 233References 234

14 Mobility Management 23714.1 Transitions between Mobility Management States 237

14.1.1 S1 Release Procedure 23714.1.2 Paging Procedure 23914.1.3 Service Request Procedure 239

14.2 Cell Reselection in RRC_IDLE 24114.2.1 Objectives 241

xiv Contents

14.2.2 Measurement Triggering on the Same LTE Frequency 24114.2.3 Cell Reselection to the Same LTE Frequency 24214.2.4 Measurement Triggering on a Different LTE Frequency 24314.2.5 Cell Reselection to a Different LTE Frequency 24414.2.6 Fast Moving Mobiles 24414.2.7 Tracking Area Update Procedure 24514.2.8 Network Reselection 246

14.3 Measurements in RRC_CONNECTED 24714.3.1 Objectives 24714.3.2 Measurement Procedure 24714.3.3 Measurement Reporting 24814.3.4 Measurement Gaps 249

14.4 Handover in RRC_CONNECTED 25014.4.1 X2 Based Handover Procedure 25014.4.2 Handover Variations 252References 253

15 Inter-operation with UMTS and GSM 25515.1 System Architecture 255

15.1.1 Architecture of the 2G/3G Packet Switched Domain 25515.1.2 S3/S4-Based Inter-operation Architecture 25715.1.3 Gn/Gp-Based Inter-operation Architecture 258

15.2 Power-On Procedures 25915.3 Mobility Management in RRC_IDLE 259

15.3.1 Cell Reselection 25915.3.2 Routing Area Update Procedure 26015.3.3 Idle Mode Signalling Reduction 262

15.4 Mobility Management in RRC_CONNECTED 26215.4.1 RRC Connection Release with Redirection 26215.4.2 Measurement Procedures 26415.4.3 Optimized Handover 265References 268

16 Inter-operation with Non-3GPP Technologies 27116.1 Generic System Architecture 271

16.1.1 Network-Based Mobility Architecture 27116.1.2 Host-Based Mobility Architecture 27316.1.3 Access Network Discovery and Selection Function 274

16.2 Generic Signalling Procedures 27516.2.1 Overview of the Attach Procedure 27516.2.2 Authentication and Key Agreement 27616.2.3 PDN Connectivity Establishment 27816.2.4 Radio Access Network Reselection 280

16.3 Inter-Operation with cdma2000 HRPD 28016.3.1 System Architecture 28016.3.2 Preregistration with cdma2000 281

Contents xv

16.3.3 Cell Reselection in RRC_IDLE 28216.3.4 Measurements and Handover in RRC_CONNECTED 283References 286

17 Self-Optimizing Networks 28917.1 Self-Configuration of an eNB 289

17.1.1 Automatic Configuration of the Physical Cell Identity 28917.1.2 Automatic Neighbour Relations 29017.1.3 Random Access Channel Optimization 291

17.2 Inter-Cell Interference Coordination 29217.3 Mobility Management 292

17.3.1 Mobility Load Balancing 29217.3.2 Mobility Robustness Optimization 29317.3.3 Energy Saving 295

17.4 Radio Access Network Information Management 29517.4.1 Introduction 29517.4.2 Transfer of System Information 29617.4.3 Transfer of Self-Optimization Data 297

17.5 Drive Test Minimization 297References 298

18 Enhancements in Release 9 30118.1 Multimedia Broadcast/Multicast Service 301

18.1.1 Introduction 30118.1.2 Multicast/Broadcast over a Single Frequency Network 30218.1.3 Implementation of MBSFN in LTE 30218.1.4 Architecture of MBMS 30418.1.5 Operation of MBMS 305

18.2 Location Services 30618.2.1 Introduction 30618.2.2 Positioning Techniques 30618.2.3 Location Service Architecture 30718.2.4 Location Service Procedures 308

18.3 Other Enhancements in Release 9 30918.3.1 Dual Layer Beamforming 30918.3.2 Commercial Mobile Alert System 310References 310

19 LTE-Advanced and Release 10 31319.1 Carrier Aggregation 313

19.1.1 Principles of Operation 31319.1.2 UE Capabilities 31419.1.3 Scheduling 31619.1.4 Data Transmission and Reception 31619.1.5 Uplink and Downlink Feedback 31719.1.6 Other Physical Layer and MAC Procedures 317

xvi Contents

19.1.7 RRC Procedures 31719.2 Enhanced Downlink MIMO 318

19.2.1 Objectives 31819.2.2 Downlink Reference Signals 31819.2.3 Downlink Transmission and Feedback 320

19.3 Enhanced Uplink MIMO 32119.3.1 Objectives 32119.3.2 Implementation 321

19.4 Relays 32219.4.1 Principles of Operation 32219.4.2 Relaying Architecture 32319.4.3 Enhancements to the Air Interface 324

19.5 Heterogeneous Networks 32419.5.1 Introduction 32419.5.2 Enhanced Inter-Cell Interference Coordination 32519.5.3 Enhancements to Self-Optimizing Networks 326

19.6 Traffic Offload Techniques 32619.6.1 Local IP Access 32619.6.2 Selective IP Traffic Offload 32719.6.3 Multi-Access PDN Connectivity 32719.6.4 IP Flow Mobility 329

19.7 Overload Control for Machine-Type Communications 330References 331

20 Releases 11 and 12 33320.1 Coordinated Multipoint Transmission and Reception 333

20.1.1 Objectives 33320.1.2 Scenarios 33420.1.3 CoMP Techniques 33520.1.4 Standardization 33620.1.5 Performance 337

20.2 Enhanced Physical Downlink Control Channel 33720.3 Interference Avoidance for in Device Coexistence 33820.4 Machine-Type Communications 339

20.4.1 Device Triggering 33920.4.2 Numbering, Addressing and Identification 340

20.5 Mobile Data Applications 34020.6 New Features in Release 12 341

20.6.1 Proximity Services and Device to Device Communications 34120.6.2 Dynamic Adaptation of the TDD Configuration 34220.6.3 Enhancements for Machine-Type Communications and Mobile Data 34420.6.4 Traffic Offloading Enhancements 344

20.7 Release 12 Studies 34520.7.1 Enhancements to Small Cells and Heterogeneous Networks 34520.7.2 Elevation Beamforming and Full Dimension MIMO 346References 346

Contents xvii

21 Circuit Switched Fallback 34921.1 Delivery of Voice and Text Messages over LTE 349

21.1.1 The Market for Voice and SMS 34921.1.2 Third Party Voice over IP 35021.1.3 The IP Multimedia Subsystem 35121.1.4 VoLGA 35121.1.5 Dual Radio Devices 35221.1.6 Circuit Switched Fallback 353

21.2 System Architecture 35321.2.1 Architecture of the 2G/3G Circuit Switched Domain 35321.2.2 Circuit Switched Fallback Architecture 354

21.3 Attach Procedure 35521.3.1 Combined EPS/IMSI Attach Procedure 35521.3.2 Voice Domain Preference and UE Usage Setting 356

21.4 Mobility Management 35721.4.1 Combined Tracking Area/Location Area Update Procedure 35721.4.2 Alignment of Tracking Areas and Location Areas 35721.4.3 Cell Reselection to UMTS or GSM 358

21.5 Call Setup 35921.5.1 Mobile-Originated Call Setup using RRC Connection Release 35921.5.2 Mobile Originated Call Setup using Handover 36121.5.3 Signalling Messages in the Circuit Switched Domain 36221.5.4 Mobile-Terminated Call Setup 36321.5.5 Returning to LTE 364

21.6 SMS over SGs 36521.6.1 System Architecture 36521.6.2 SMS Delivery 365

21.7 Circuit Switched Fallback to cdma2000 1xRTT 36621.8 Performance of Circuit Switched Fallback 367

References 368

22 VoLTE and the IP Multimedia Subsystem 37122.1 Introduction 371

22.1.1 The IP Multimedia Subsystem 37122.1.2 VoLTE 37222.1.3 Rich Communication Services 372

22.2 Hardware Architecture of the IMS 37322.2.1 High-Level Architecture 37322.2.2 Call Session Control Functions 37422.2.3 Application Servers 37522.2.4 Home Subscriber Server 37522.2.5 User Equipment 37522.2.6 Relationship with LTE 37622.2.7 Border Control Functions 37722.2.8 Media Gateway Functions 37822.2.9 Multimedia Resource Functions 379

xviii Contents

22.2.10 Security Architecture 38022.2.11 Charging Architecture 380

22.3 Signalling Protocols 38122.3.1 Session Initiation Protocol 38122.3.2 Session Description Protocol 38222.3.3 Other Signalling Protocols 382

22.4 Service Provision in the IMS 38222.4.1 Service Profiles 38222.4.2 Media Feature Tags 38322.4.3 The Multimedia Telephony Service for IMS 383

22.5 VoLTE Registration Procedure 38422.5.1 Introduction 38422.5.2 LTE Procedures 38422.5.3 Contents of the REGISTER Request 38522.5.4 IMS Registration Procedure 38722.5.5 Routing of SIP Requests and Responses 38822.5.6 Third-Party Registration with Application Servers 38922.5.7 Subscription for Network-Initiated Deregistration 389

22.6 Call Setup and Release 39022.6.1 Contents of the INVITE Request 39022.6.2 Initial INVITE Request and Response 39122.6.3 Acceptance of the Initial INVITE 39322.6.4 Establishment of a Call to a Circuit Switched Network 39622.6.5 Call Release 396

22.7 Access Domain Selection 39722.7.1 Mobile-Originated Calls 39722.7.2 Mobile-Terminated Calls 398

22.8 Single Radio Voice Call Continuity 39822.8.1 Introduction 39822.8.2 SRVCC Architecture 39922.8.3 Attach, Registration and Call Setup Procedures 40022.8.4 Handover Preparation 40022.8.5 Updating the Remote Leg 40122.8.6 Releasing the Source Leg 40322.8.7 Handover Execution and Completion 40322.8.8 Evolution of SRVCC 404

22.9 IMS Centralized Services 40522.10 IMS Emergency Calls 406

22.10.1 Emergency Call Architecture 40622.10.2 Emergency Call Setup Procedure 407

22.11 Delivery of SMS Messages over the IMS 40822.11.1 SMS Architecture 40822.11.2 Access Domain Selection 409References 410

Contents xix

23 Performance of LTE and LTE-Advanced 41323.1 Peak Data Rates of LTE and LTE-Advanced 413

23.1.1 Increase of the Peak Data Rate 41323.1.2 Limitations on the Peak Data Rate 415

23.2 Coverage of an LTE Cell 41623.2.1 Uplink Link Budget 41623.2.2 Downlink Link Budget 41823.2.3 Propagation Modelling 41923.2.4 Coverage Estimation 420

23.3 Capacity of an LTE Cell 42123.3.1 Capacity Estimation 42123.3.2 Cell Capacity Simulations 422

23.4 Performance of Voice over IP 42423.4.1 AMR Codec Modes 42423.4.2 Transmission of AMR Frames on the Air Interface 42523.4.3 Transmission of AMR Frames in the Fixed Network 426References 427

Bibliography 429

Index 431

Preface

This book is about the world’s dominant 4G mobile telecommunication system, LTE.In writing the book, my aim has been to give the reader a concise, system level introduction

to the technology that LTE uses. The book covers the whole of the system, both the techniquesused for radio communication between the base station and the mobile phone, and thetechniques used to transfer data and signalling messages across the network. I have avoidedgoing into excessive detail, which is more appropriate for specialized treatments of individualtopics and for the LTE specifications themselves. Instead, I hope that the reader will comeaway from this book with a sound understanding of the system and of the way in which itsdifferent components interact. The reader will then be able to tackle the more advanced booksand the specifications with confidence.

The target audience is twofold. Firstly, I hope that the book will be valuable for engineerswho are working on LTE, notably those who are transferring from other technologies such asGSM, UMTS and cdma2000, those who are experts in one part of LTE but who want to under-stand the system as a whole and those who are new to mobile telecommunications altogether.Secondly, the book should give a valuable overview to those who are working in non technicalroles, such as project managers, marketing executives and intellectual property consultants.

Structurally, the book has four parts. The first part lays out the foundations that the readerwill need in the remainder of the book. Chapter 1 is an introduction, which relates LTE toearlier mobile telecommunication systems and lays out its requirements and key technicalfeatures. Chapter 2 covers the architecture of the system, notably the hardware components andcommunication protocols that it contains and its use of radio spectrum. Chapter 3 reviews theradio transmission techniques that LTE has inherited from earlier mobile telecommunicationsystems, while Chapters 4 and 5 describe the more recent techniques of orthogonal frequencydivision multiple access and multiple input multiple output antennas.

The second part of the book covers the air interface of LTE. Chapter 6 is a high level descrip-tion of the air interface, while Chapter 7 relates the low level procedures that a mobile phoneuses when it switches on, to discover the LTE base stations that are nearby. Chapter 8 coversthe low level procedures that the base station and mobile phone use to transmit and receiveinformation, while Chapter 9 covers a specific procedure, random access, by which the mobilephone can contact a base station without prior scheduling. Chapter 10 covers the higher levelparts of the air interface, namely the medium access control, radio link control and packet dataconvergence protocols.

The third part covers the signalling procedures that govern how a mobile phone behaves.In Chapter 11, we describe the high level procedures that a mobile phone uses when itswitches on, to register itself with the network and establish communications with the outside

xxii Preface

world. Chapter 12 covers the security procedures used by LTE, while Chapter 13 coversthe procedures that manage the quality of service and charging characteristics of a datastream. Chapter 14 describes the mobility management procedures that the network uses tokeep track of the mobile’s location. Chapter 15 describes how LTE inter-operates with theearlier technologies of GSM and UMTS, while Chapter 16 discusses inter-operation withother technologies such as wireless local area networks and cdma2000. Chapter 17 covers theself-configuration and self-optimization capabilities of LTE.

The final part covers more specialized topics. Chapters 18, 19 and 20 describe the enhance-ments that have been made to LTE in later releases of the specifications, notably an enhancedversion of the technology that is known as LTE-Advanced. Chapters 21 and 22 cover the twomost important solutions for the delivery of voice calls to LTE devices, namely circuit switchedfallback and the IP multimedia subsystem. Finally, Chapter 23 reviews the performance ofLTE and discusses the techniques that are used to estimate the coverage and capacity of anLTE network.

LTE has a large number of acronyms, and it is hard to talk about the subject without usingthem. However, they can make the material appear unnecessarily impenetrable to a newcomer,so I have aimed to keep the use of acronyms to a reasonable minimum, often preferring thefull name or a colloquial one. There is a full list of abbreviations in the introductory materialand new terms are highlighted using italics throughout the text.

I have also endeavoured to keep the book’s mathematical content to the minimum neededto understand the system. The LTE air interface makes extensive use of complex numbers,Fourier transforms and matrix algebra, but the reader will not require any prior knowledgeof these in order to understand the book. We do make limited use of complex numbers inChapters 3 and 4 to illustrate our discussion of modulation, and introduce Fourier transformsand matrices in subsections of Chapters 4 and 5 to cover the more advanced aspects of orthog-onal frequency division multiple access and multiple antennas. Readers can, however, skip thismaterial without detracting from their overall appreciation of the subject.

Acknowledgements

Many people have given me assistance, support and advice during the creation of this book.I am especially grateful to Liz Wingett, Susan Barclay, Sophia Travis, Sandra Grayson, MarkHammond and the rest of the publishing team at John Wiley & Sons, Ltd for the expert know-ledge and gentle encouragement that they have supplied throughout the production process.

I am indebted to Michael Salmon and Geoff Varrall for encouraging me to write the first edi-tion of this book and to the publishing team at Wiley for requesting a second. The advice andfeedback I have received while preparing the manuscript have been invaluable and have givenme many opportunities to correct errors and improve the material. In this respect, I would par-ticularly like to thank Jeff Cartwright, Joseph Hoy, Julian Nolan, Michael Salmon, MohammadAnas, Obi Chiemeka, Pete Doherty, Les Granfield, Karl van Heeswijk, Kit Kilgour and PaulMason. I am especially indebted to Nicola Rivers, for her support and encouragement through-out the preparation of the second edition. Naturally, the responsibility for any remaining errorsor omissions in the text, and for any lack of clarity in the explanations, is entirely my own.

Much of my knowledge of the more detailed aspects of LTE, notably of circuit switched fall-back and the IP multimedia subsystem, has been gathered while delivering courses on behalfof various training providers. I am indebted to the directors and staff of Imagicom, InformaTelecoms Academy, Wray Castle and Mpirical, for the support and learning opportunitiesthat they have provided to me. I would also like to extend my thanks to the delegates whohave attended my training courses on LTE. Their questions and corrections have extended myknowledge of the subject, while their feedback has regularly suggested ways to explain topicsmore effectively.

Several diagrams in this book have been reproduced from the technical specifications forLTE, with permission from the European Telecommunications Standards Institute (ETSI),© 2013, 2012, 2011, 2010, 2006. 3GPP™ TSs and TRs are the property of ARIB, ATIS,CCSA, ETSI, TTA and TTC who jointly own the copyright for them. They are subject to fur-ther modifications and are therefore provided to you ‘as is’ for information purposes only.Further use is strictly prohibited.

Analysys Mason Limited kindly supplied the market research data underlying the illustra-tions of network traffic and operator revenue in Figures 1.6 and 21.1. I would like to extend myappreciation to Hilary Bailey, Morgan Mullooly, Terry Norman and James Allen for provid-ing this information. The measurements of network traffic in Figure 1.5 and the subscriptiondata underlying Figures 1.9 and 1.10 are by Ericsson, and I am grateful to Elin Pettersson andSvante Bergqvist for making these available.

List of Abbreviations

16-QAM 16 quadrature amplitude modulation1G First generation1xRTT 1x radio transmission technology2G Second generation3G Third generation3GPP Third Generation Partnership Project3GPP2 Third Generation Partnership Project 24G Fourth generation64-QAM 64 quadrature amplitude modulation

AAA Authentication, authorization and accountingABMF Account balance management functionABS Almost blank subframeACK Positive acknowledgementACM Address complete messageADC Analogue to digital converterAES Advanced Encryption StandardAF Application function/Assured forwardingAKA Authentication and key agreementAM Acknowledged modeAMBR Aggregate maximum bit rateAMR Adaptive multi rateAMR-WB Wideband adaptive multi rateANDSF Access network discovery and selection functionANM Answer messageAPI Application programming interfaceAPN Access point nameAPN-AMBR Per APN aggregate maximum bit rateARIB Association of Radio Industries and BusinessesARP Allocation and retention priorityARQ Automatic repeat requestAS Access stratum/Application serverASME Access security management entityATCF Access transfer control functionATGW Access transfer gatewayATIS Alliance for Telecommunications Industry Solutions

xxvi List of Abbreviations

AuC Authentication centreAVP Attribute value pair/Audio visual profileAWS Advanced Wireless Services

B2BUA Back to back user agentBBERF Bearer binding and event reporting functionBBF Bearer binding functionBCCH Broadcast control channelBCH Broadcast channelBD Billing domainBE Best effortBGCF Breakout gateway control functionBICC Bearer independent call controlBM-SC Broadcast/multicast service centreBPSK Binary phase shift keyingBSC Base station controllerBSR Buffer status reportBSSAP+ Base station subsystem application part plusBSSGP Base station system GPRS protocolBTS Base transceiver station

CA Carrier aggregationCAMEL Customized applications for mobile network enhanced logicCBC Cell broadcast centreCBS Cell broadcast serviceCC Call control/Component carrierCCCH Common control channelCCE Control channel elementCCO Cell change orderCCSA China Communications Standards AssociationCDF Charging data functionCDMA Code division multiple accessCDR Charging data recordCFI Control format indicatorCGF Charging gateway functionCIF Carrier indicator fieldCLI Calling line identificationCM Connection managementCMAS Commercial mobile alert systemC-MSISDN Correlation mobile subscriber ISDN numberCoMP Coordinated multi-point transmission and receptionCOST European Cooperation in Science and TechnologyCP Cyclic prefixCQI Channel quality indicatorCRC Cyclic redundancy checkC-RNTI Cell radio network temporary identifierCS Circuit switched

List of Abbreviations xxvii

CS/CB Coordinated scheduling and beamformingCSCF Call session control functionCSFB Circuit switched fallbackCSG Closed subscriber groupCSI Channel state informationCS-MGW Circuit switched media gatewayCTF Charging trigger function

D2D Device to deviceDAC Digital-to-analogue converterdB DecibeldBi Decibels relative to an isotropic antennadBm Decibels relative to one milliwattDCCH Dedicated control channelDCI Downlink control informationDeNB Donor evolved Node BDFT Discrete Fourier transformDFT-S-OFDMA Discrete Fourier transform spread OFDMADHCP Dynamic host configuration protocolDiffServ Differentiated servicesDL DownlinkDL-SCH Downlink shared channelDNS Domain name serverDPS Dynamic point selectionDRS Demodulation reference signalDRVCC Dual radio voice call continuityDRX Discontinuous receptionDSCP Differentiated services code pointDSL Digital subscriber lineDSMIP Dual-stack mobile IPDTCH Dedicated traffic channelDTM Dual transfer modeDTMF Dual tone multi-frequency

EAG Explicit array gaineAN Evolved access networkEAP Extensible authentication protocolEATF Emergency access transfer functionECGI E-UTRAN cell global identifierECI E-UTRAN cell identityECM EPS connection managementECN Explicit congestion notificationE-CSCF Emergency call session control functionEDGE Enhanced Data Rates for GSM EvolutionEEA EPS encryption algorithmEF Expedited forwardingeHRPD Evolved high rate packet data

xxviii List of Abbreviations

EIA EPS integrity algorithmEICIC Enhanced inter cell interference coordinationEIR Equipment identity registerEIRP Equivalent isotropic radiated powereMBMS Evolved MBMSEMM EPS mobility managementeNB Evolved Node BEPC Evolved packet coreePCF Evolved packet control functionEPDCCH Enhanced physical downlink control channelePDG Evolved packet data gatewayEPRE Energy per resource elementEPS Evolved packet systemE-RAB Evolved radio access bearerERF Event reporting functionESM EPS session managementE-SMLC Evolved serving mobile location centreESP Encapsulating security payloadETSI European Telecommunications Standards InstituteETWS Earthquake and tsunami warning systemE-UTRAN Evolved UMTS terrestrial radio access networkEV-DO Evolution data optimized

FCC Federal Communications CommissionFDD Frequency division duplexFDMA Frequency division multiple accessFD-MIMO Full-dimension MIMOFFT Fast Fourier transformFTP File transfer protocol

GBR Guaranteed bit rateGCP Gateway control protocolGERAN GSM EDGE radio access networkGGSN Gateway GPRS support nodeGMLC Gateway mobile location centreGMM GPRS mobility managementGNSS Global navigation satellite systemGP Guard periodGPRS General Packet Radio ServiceGPS Global Positioning SystemGRE Generic routing encapsulationGRX GPRS roaming exchangeGSM Global System for Mobile CommunicationsGSMA GSM AssociationGTP GPRS tunnelling protocolGTP-C GPRS tunnelling protocol control partGTP-U GPRS tunnelling protocol user part