Cellular communications : a comprehensive and practical guide · 2015-02-13 · 1.7.7 Design,Optimization,andTestingToolManufacturers 40 1.7.8 AppplicationProviders 40 1.8 Phases

Cellular Communications

A Comprehensive and Practical Guide

Nishith D. TripathiAward Solutions, Inc.

Jeffrey H. Reed

Virginia Tech University

Wiley

CONTENTS

Preface xxiii

Acknowledgments xxix

PART I FUNDAMENTAL CONCEPTS OF CELLULAR

COMMUNICATIONS

1 Introduction to Cellular Communications 3

1.1 Motivation for Cellular Communications 4

1.2 The History of Wireless Communications and the Birth of a

Cellular System 4

1.2.1 Once Upon a Time... A Really Brief History of

Communications 5

1.2.2 Frequency Spectrum Allocation 5

1.2.3 Pre-Cellular Mobile Telephone Systems 8

1.2.4 The Advent of Cellular Systems 9

1.3 Concepts of a Cellular System 11

1.3.1 Network Architecture 11

1.3.2 Air Interface 12

viii CONTENTS

1.3.3 Frequency Reuse 13

1.3.4 Sectorization and Its Impact on Quality and Capacity 20

1.4 Concepts of Duplexing and Multiple Access 22

1.4.1 Duplexing Methods 22

1.4.2 Multiple Access Methods 24

1.5 Types of Interference 26

1.5.1 Adjacent Channel Interference 26

1.5.2 Co-Channel Interference 27

1.6 Evolution of Cellular Standards 28

1.6.1 Evolutionary Path of Cellular Standards 28

1.6.2 Spectrum Allocation in the United States 32

1.6.3 Spectrum Allocation Outside the U.S. 34

1.7 Ecosystem of Cellular Systems 34

1.7.1 Service Providers 35

1.7.2 Mobile Device Manufacturers 36

1.7.3 Radio Network Infrastructure Vendors 37

1.7.4 Baseband Chipset Manufacturers 37

1.7.5 Original Equipment Manufacturers 39

1.7.6 Core Network Vendors 39

1.7.7 Design, Optimization, and Testing Tool Manufacturers 40

1.7.8 Appplication Providers 40

1.8 Phases of a Cellular System 42

1.8.1 Phase 1: Specifications of the Standard 42

1.8.2 Phase 2: Prototype Design and Lab Tests 43

1.8.3 Phase 3: Field Trials 43

1.8.4 Phase 4: Commercial Deployments 44

1.8.5 Phase 5: Optimization 44

1.9 Performance of Cellular Systems 45

1.9.1 Sector Capacity and Call Blocking Probability 45

1.9.2 Accessibility, Access Failure Rate, and Paging Failure

Rate 47

1.9.3 Retainability and Call-Drop Rate 47

1.9.4 Error Rate and Quality of Service 47

1.9.5 Cell-Edge Reliability and Cell-Area Reliability 48

1.9.6 Peak User Data Rate 49

1.9.7 Average Cell or Sector Throughput and User-Perceived

Throughput 49

1.9.8 Latency or Delay 50

CONTENTS iX

1.9.9 Delay Jitter 50

1.10 End-User Services 50

1.11 Points to Remember 52

2 Elements of a Digital Communication System 55

2.1 Overview of a Digital Cellular Communication System 56

2.2 Transceiver Operations in a Digital Cellular System 57

2.3 Information Bits: Construction at the Transmitter and Retrieval

at the Receiver 59

2.3.1 Linear Predictive Speech Coding: A Simplistic View 61

2.3.2 Enhanced Variable-Rate Codec 62

2.3.3 Adaptive Multirate Codec 66

2.4 Forward Error Correction Coding and Decoding 70

2.4.1 Convolutional Coding at the Transmitter 72

2.4.2 Example Convolutional Decoding at the Receiver 74

2.4.3 Turbo Coding at the Transmitter 83

2.4.4 Turbo Decoding at the Receiver 85

2.4.5 What Should I Choose: Convolutional or Turbo? 86

2.5 Interleaving and De-Interleaving 87

2.6 Digital Modulation and Demodulation 89

2.6.1 Modulation Schemes 90

2.6.2 Demodulation Approaches 96

2.6.3 Choosing a Modulation Scheme 99

2.7 RF Processor Functions at the Transmitter and the Receiver 100

2.8 Points to Remember 109

3 Radio Frequency Propagation 111

3.1 Radio Frequency Waves 111

3.2 Free-Space Propagation 113

3.3 Cellular Propagation Mechanisms 116

3.3.1 Reflection 116

3.3.2 Diffraction 117

3.3.3 Scattering 119

3.3.4 Absorption and Penetration 120

3.4 Prediction of Received Signal Strength 121

3.4.1 Distance-Based Path Loss 124

3.4.2 Large-Scale Fading 128

3.4.3 Small-Scale Fading 131

X CONTENTS

3.5 Points to Remember 153

4 IP and Associated Technologies for a Cellular System 155

4.1 Why Internet Protocol? (Or, Perhaps, Why Not Internet

Protocol?) 156

4.2 Protocol Stack for the Internet 159

4.2.1 Overview of the Transport Layer (Layer 4) Protocols 160

4.2.2 Overview of the Internetwork Layer (Layer 3) Protocols 173

4.2.3 Overview of the Link Layer (Layer 2) Protocols 184

4.3 Routing and Forwarding of IP Packets 193

4.4 Transport of Information within the Network Infrastructure 200

4.5 Voice-Over-IP-Related Protocols 204

4.5.1 Session Initiation Protocol 206

4.5.2 Session Description Protocol 209

4.5.3 Real-Time Transport Protocol and Real-Time Transport

Control Protocol 211

4.6 A Potpourri of IP-Centric Protocols 213

4.6.1 Dynamic Host Configuration Protocol 213

4.6.2 Mobile IP 214

4.6.3 Domain Name System 220

4.6.4 RADIUS and Diameter 222

4.6.5 IP Quality-of-Service Implementation: Integrated

Services and Differentiated Services 224

4.6.6 IP Tunneling, GTP, and GRE 228

4.6.7 IPsec 231

4.6.8 Robust Header Compression 231

4.7 Essence of IPv6 232

4.8 Points to Remember 235

PART II 2G, 2.5G, AND 3G CELLULAR TECHNOLOGIES

5 Overview of GSM 239

5.1 Introduction 240

5.1.1 The Origin of GSM and GSM Milestones in Two

Minutes 240

5.1.2 Highlights of a GSM System 241

5.2 GSM System Architecture 242

5.2.1 Base Station System 244

5.2.2 Core Network 247

CONTENTS xi

5.3 Air-Interface Protocol Stack between MS and BSS 249

5.3.1 High-Level View of MS-BSS Communications 249

5.3.2 Air-Interface Protocol Stack: A Brief Overview 251

5.4 Radio Interface: Frame Structure and Channels 259

5.4.1 Frequency and Time Structures 259

5.4.2 Air-Interface Channels 263

5.4.3 Bursts'. An Inside Look 267

5.5 Network Acquisition 269

5.5.1 Beyond Radio Network Acquisition: MS-Core-

Network Communications 272

5.6 Voice Call Setup 279

5.6.1 MS-Originated Call Setup 279

5.6.2 MS-Terminated Call Setup and Paging Procedure 281

5.7 Mobility Management in Idle Mode 282

5.8 Mobility Management in Active or Connected Mode 283

5.8.1 What are the Channel Conditions? 284

5.8.2 Making a Handover Decision: Who is in Charge

Around Here? 287

5.8.3 Follow the Leader: Handover Completion 293

5.9 Power Control 294

5.9.1 A Detailed Look at Power Control 295

5.9.2 Further Reduction in the Transmit Power Consumption:DTX 297

5.10 Deployment Considerations 298

5.11 Evolution of GSM 302

5.12 Points to Remember 302

6 GPRS and EDGE 305

6.1 Introduction 306

6.1.1 The Motivation for GPRS 306

6.1.2 The Motivation for EDGE 308

6.1.3 GPRS in Two Minutes 308

6.1.4 EDGE in Two Minutes 309

6.2 System Architecture 310

6.2.1 Packet-Domain Core Network Architecture: An

Overview 310

6.2.2 A Detailed View of the Components of the Packet-

Domain Core Network 312

XM CONTENTS

6.2.3 Interfaces of the Packet-Domain Core Network 321

6.2.4 End-to-End View of the Data Transfer 323

6.3 MS-BSS Air-Interface Communications 324

6.3.1 Physical Layer of GPRS and EDGE 325

6.3.2 RLC/MAC Layer and Its Functions 334

6.4 Radio Interface: Frame Structure and Channels 342

6.4.1 Review of Timing Structures 342

6.4.2 New Logical Channels in GPRS and EDGE 344

6.4.3 Association of Logical and Physical Channels 346

6.5 Network Acquisition 348

6.5.1 Cell Search and Synchronization: A Brief Review 348

6.5.2 The MS's GPRS Attach Procedure: Making the First

Contact with the Core Network 349

6.5.3 Getting Ready for Packet Data Transfer: PDP Context

Activation 351

6.6 Packet Transfer in GPRS and EDGE 353

6.6.1 MS-Originated Packet Transfer 353

6.6.2 MS-Terminated Packet Transfer 355

6.6.3 Management of Circuit-Switched and GPRS Paging 356

6.7 Mobility Management 358

6.7.1 Routing Area Update: STANDBY State Mobility

Management 358

6.7.2 Mobility Management in READY State 359

6.8 Deployment Considerations and Network Evolution 361

6.9 Points to Remember 362

7 Fundamentals of CDMA, WCDMA, and IS-95 363

7.1 A Brief Introduction to CDMA, WCDMA, and IS-95 364

7.2 CDMA or WCDMA: An Efficient Resource-Sharing Technique 366

7.3 Characteristics of CDMA 369

7.3.1 Wideband Transmission 369

7.3.2 Frequency Reuse and Impact of Sectorization 370

7.3.3 Interference and its Control in CDMA 371

7.3.4 Handoff 375

7.3.5 Power Control 381

7.3.6 Capacity of a CDMA System 388

7.4 IS-95 System Architecture 390

7.5 IS-95 MS-Radio-Network Communications: An Overview 391

CONTENTS xiii

7.5.1 Duplexing: Simultaneous Downlink and UplinkTransmissions 392

7.5.2 IS-95 Protocol Stack Overview 392

7.5.3 Downlink and Uplink Radio Channels of IS-95 394

7.5.4 Physical Layer (Layer 1) Processing 399

7.5.5 Multiplex Sublayer (Between Layer 1 and Layer 2):

An Overview 403

7.5.6 Layer 2 Versus Layer 3 404

7.6 IS-95 Call Setup 405

7.7 IS-95 Mobility Management 407

7.7.1 Power-On Network Acquisition—One-Way Traffic! 407

7.7.2 MS to Network: "Here I Am"—Registration and Other

Idle Mode Activities 408

7.7.3 Handoff in Connected or Traffic Mode—Now We Are

Getting Really Busy! 411

7.8 IS-95 Power Control 414

7.8.1 Uplink Power Control 415

7.8.2 Downlink Power Control 416

7.9 IS-95: Deployment, Evolution, and Enhancements 418

7.10 Points to Remember 420

8 CDMA20001x 423

8.1 A Brief Overview of CDMA2000 424

8.2 CDMA2000 lx Network Architecture 426

8.2.1 Overview of the Network Architecture 426

8.2.2 A Detailed View of the Packet-Switched Core Network 429

8.3 MS-Radio-Access-Network Communications 431

8.3.1 Overview of Air-Interface Protocol Stack 431

8.3.2 Radio Channels and Radio Configurations of lx 433

8.3.3 Overview of Physical Layer (Layer 1) Processing 441

8.3.4 Overview of Link Layer (Layer 2) Processing 445

8.3.5 A Brief Overview of Upper-Layer Processing 454

8.4 lx Call Setup 454

8.4.1 Voice Call Setup in lx: An Overview 455

8.4.2 Voice Call Setup in lx: A Closer Look 456

8.4.3 How About Data Call Setup in lx? 459

8.4.4 What About MS-Terminated Call Setup? 460

XiV CONTENTS

8.5 Over-the-Air Transmission of Traffic for Forward and Reverse

Links 462

8.5.1 Forward Link Packet Data Transmission 462

8.5.2 Reverse Link Packet Data Transmission 467

8.6 Mobility Management 468

8.6.1 Registration and Authentication 469

8.6.2 Using the Access Channel 472

8.6.3 Handoff in Connected Mode: lx Enhancements 477

8.7 lx Power Control 481

8.7.1 Reverse Link Power Control for the Reverse

Fundamental Channel 481

8.7.2 Forward Link Power Control for the Forward

Fundamental Channel 482

8.8 lx Deployment and Evolution 484

8.9 Points to Remember 485

9 Universal Mobile Telecommunication System Release 99 487

9.1 Universal Mobile Telecommunication System Release 99:

Executive Summary 488

9.2 UMTS Network Architecture 489

9.2.1 Radio Network Subsystem 491

9.2.2 Protocol Stacks: From User Equipment to the Edge of

the Network 493

9.3 Radio Interface Protocol Stack between UE and UTRAN 495

9.3.1 Radio Interface Protocol Stack: A Brief Overview 495

9.3.2 Physical Layer 499

9.3.3 Medium Access Control Sublayer 503

9.3.4 Radio Link Control Sublayer 504

9.3.5 Packet Data Convergence Protocol Sublayer 510

9.3.6 Broadcast-Multicast Control Sublayer 511

9.3.7 Radio Resource Control Layer 512

9.4 Radio Interface Between the UE and the UTRAN 515

9.4.1 Overview of Frame Structure and Radio Channels 515

9.4.2 Orthogonal Variable Spreading Factor Codes 519

9.4.3 Primary Synchronization Channel 523

9.4.4 Secondary Synchronization Channel 523

9.4.5 Primary Common Pilot Channel 524

9.4.6 Primary Common Control Physical Channel 525

CONTENTS XV

9.4.7 Page Indicator Channel 526

9.4.8 Secondary—Common Control Physical Channel 527

9.4.9 Physical Random Access Channel 528

9.4.10 Acquisition Indicator Channel 533

9.4.11 UplinkDedicated Physical Data Channel and Dedicated

Physical Control Channel 534

9.4.12 Downlink Dedicated Physical Channel and Dedicated

Physical Control Channel 535

9.4.13 Combining of the Downlink Channels in a Cell 536

9.4.14 Transmission of Uplink Channels by User Equipment 539

9.5 Cell Search and Synchronization 539

9.5.1 Overview of Power-Up Synchronization and Cell

Search 539

9.5.2 Power-Up Synchronization and Cell Search: A Closer

Look 540

9.5.3 Beyond Synchronization: User Equipment and Core

Network Communications 542

9.6 Voice Call Setup 544

9.6.1 Overview of Voice Call Setup and Teardown 544

9.6.2 Detailed Voice Call Setup 545

9.7 Data Call Setup 553

9.7.1 Overview of the Data Session Setup 553

9.7.2 Detailed Data Session Setup 554

9.8 Mobility Management 557

9.8.1 Idle Mode Mobility: An Overview 558

9.8.2 Connected Mode Mobility: An Overview of Basic

Concepts 559

9.8.3 Stages of Intra-Frequency Handover: A Closer Look 562

9.8.4 Intra-UMTS Inter-Frequency and Inter-RAT Handover 568

9.8.5 Compressed Mode 569

9.9 Power Control 573

9.9.1 Uplink Closed-Loop Power Control 574

9.9.2 Downlink Closed-Loop Power Control 579

9.10 Quality-of-Service in the Universal Mobile Telecommunication

System 580

9.11 Evolution of the Universal Mobile Telecommunication System 581

9.12 Points to Remember 583

XVi CONTENTS

10 1xEvolution-Data-Optimized Revision 0 585

10.1 lxEV-DO: Executive Summary 586

10.2 Overview of Call Setup and Data Transmission 587

10.3 Network Architecture 590

10.4 lxEV-DO Protocol Stack: An Overview 591

10.5 Introduction to Radio Channels and Timing Structure 593

10.6 A Closer Look at Forward Link Radio Channels 596

10.6.1 Pilot Channel 597

10.6.2 Medium Access Control Channel 597

10.6.3 Control Channel 600

10.6.4 Forward Traffic Channel 604

10.6.5 Combining the Forward Link Channels 610

10.7 A Closer Look at Reverse Link Channels 612

10.7.1 Access Channel 612

10.7.2 Pilot Channel and Data Channel 615

10.7.3 Data Rate Control Channel 617

10.7.4 Acknowledgment Channel 619

10.7.5 Combining of the Reverse Link Channels 621

10.8 Call Setup: A Closer Look 623

10.8.1 Session Setup 624

10.8.2 Point-to-Point Protocol Setup 628

10.8.3 Mobile Internet Protocol Setup 628

10.9 Forward Link Data Transmission: A Detailed View 630

10.10 Reverse Link Data Transmission: A Detailed View 633

10.10.1 Stage 1: Configuration of the Access Terminal with

Reverse Link Parameters 633

10.10.2 Stage 2: Fast Indications of Reverse Link Interference 635

10.10.3 Stage 3: Execution of the Reverse Link Data

Determination Algorithm 635

10.10.4 Stage 4: The Access Terminal's Data Transmission 638

10.11 Mobility Management in lxEV-DO 640

10.12 A Glimpse of lxEV-DO Optimization 642

10.12.1 RF Optimization 643

10.12.2 Parameter and Configuration Optimization 644

10.13 1 xRTT and 1 xEV-DO Interworking 645

10.14 lxEV-DO Link Budget 646

10.15 Points to Remember 649

CONTENTS xvii

11 High-Speed Downlink Packet Access 651

11.1 Overview of Third Generation Partnership Project Release 5 652

11.2 A Bird's-Eye View of High-Speed Downlink Packet Access

Data Transmission 653

11.3 High-Speed Downlink Packet Access Channels and Their Use:

A Deep Dive 655

11.3.1 High-Speed-Physical Downlink Shared Channel 655

11.3.2 High-Speed-Shared Control Channel 659

11.3.3 High-Speed-Dedicated Physical Control Channel 667

11.4 Data Transmission Process 671

11.4.1 Step 1: Reporting of Channel Conditions 671

11.4.2 Step 2: Scheduling of Users and User Packets 672

11.4.3 Step 3: Packet Transmission from the Node B and

Packet Reception at UEs 677

11.4.4 Step 4: UE Response to a Received Packet 680

11.5 High-Speed Downlink Packet Access Call Setup 681

11.6 Resource Management of the High-Speed Downlink Packet

Access Channels 683

11.7 Mobility Management in High-Speed Downlink Packet Access 685

11.8 Network and UE Architecture 689

11.8.1 Radio Interface Protocol Stack Changes from

Release 99 to Release 5 689

11.8.2 High-Speed Downlink Packet Access UE Categories 691

11.8.3 Interaction Between the Node B and the RNC for

High-Speed Downlink Packet Access 691

11.8.4 Construction of a Packet at the Node B 695

11.9 Points to Remember 697

12 1x Evolution-Data-Optimized Revision A 699

12.1 Introduction 700

12.2 Overview of Rev. A Enhancements 702

12.3 Characteristics of Physical Layer Subtypes 705

12.3.1 Overview of Physical Layer Subtypes 705

12.3.2 Reverse Link Frame Structure of Subtype 2 Physical

Layer 706

12.4 Rev. A Forward Link Channels 707

12.4.1 Overview of FL Channels 707

12.4.2 ARQ Channel: A New Forward Link Channel in Rev. A 715

xviii CONTENTS

12.5 Overview of Rev. A Reverse Link Channels 718

12.5.1 Access Channel and RRI Channel Enhancements in

Rev. A 721

12.5.2 Auxiliary Pilot Channel and DSC Channel: New

Rev. A Channels 723

12.6 Rev. A Enhancement for Call Setup and Session Setup 724

12.6.1 Session Configuration and Multiple Personalities 725

12.6.2 Generic Attribute Update Protocol 728

12.6.3 Multimode Capability Discovery Protocol 728

12.7 Rev. A Forward Link Data Transmission: A Detailed View 728

12.7.1 Overview of Enhancements in Forward Link

Transmission 728

12.7.2 DRC Enhancements 731

12.7.3 Multi-User Packets 734

12.7.4 MACIndex Enhancements 737

12.7.5 The AT's Detection of the FL Packet 739

12.7.6 Forward Link H-ARQ 739

12.8 Overview of Rev. A Reverse Link Data Rate Control 740

12.9 Reverse Link Interference Control via T2P 742

12.9.1 Motivation for T2P-Based Rate Control 743

12.9.2 What Is T2P, Anyway? 744

12.10 Subtype 2 RTC MAC Protocol Data Rate Control 745

12.10.1 Terminology for Subtype 2 and 3 RTC MAC Protocol 745

12.10.2 Overview of RL Data Transmission 750

12.10.3 A Comprehensive View of RL Data Transmission 751

12.11 Subtype 3 RTC MAC Protocol Data Rate Control 756

12.11.1 Overview of RL Data Transmission 756

12.11.2 Detailed View of RL Data Transmission 758

12.12 Rev. A QoS Control 761

12.12.1 Air-Interface QoS 762

12.12.2 Network QoS Control on R-P Interface 763

12.13 Handoff within lxEV-DO 764

12.14 Idle State Enhancements and Signaling Enhancements 766

12.15 lxEV-DO Rev. A Interworking: Rev. 0, Rev. A, and

CDMA2000 lx 767

12.16 Points to Remember 767

13 High-Speed Uplink Packet Access 769

CONTENTS XiX

13.1 Introduction to HSUPA: An Executive Summary 770

13.2 Basics of Data Transmission: A Brief Overview 771

13.2.1 Simplified HSUPA Call Setup 772

13.2.2 Some Terminology 773

13.2.3 Major Stages of Uplink Data Transmission: An

Overview 774

13.3 HSUPA Channels 777

13.3.1 The E-DCH and E-DPDCHs (Uplink) 777

13.3.2 The E-DPCCH (Uplink) 784

13.3.3 The E-AGCH (Downlink) 785

13.3.4 The E-RGCH (Downlink) 787

13.3.5 The E-HICH (Downlink) 788

13.3.6 A Really Close Look at Timing Relationships Among

HSUPA Channels 789

13.4 Prior to Data Transmission 790

13.5 Steps of Uplink Data Transmission 793

13.5.1 Scheduling Requests from the UE to the Node Bs 794

13.5.2 The Node B's Determination of Grants 794

13.5.3 Determination of the Serving Grant 798

13.5.4 E-DCH Transmission 800

13.5.5 Node B's Packet Decoding and HARQ Transmission 811

13.6 Physical Layer Retransmissions and HARQ 811

13.7 Support for User Mobility 814

13.8 System Architecture 815

13.8.1 Enhancements to the Existing Architecture 815

13.8.2 Interaction Between the Node B and the RNC for the

Management of HSUPA Channels and Resources 817

13.8.3 HSUPA UE Categories 818

13.9 Points to Remember 818

PART III IP MULTIMEDIA SUBSYSTEM AND 4G CELLULAR

TECHNOLOGIES

14 IP Multimedia Subsystem 823

14.1 Introduction to IMS: What and Why? 823

14.2 IMS, IP Convergence, and Fixed Mobile Convergence 827

14.3 History of IMS 828

14.4 IMS Architecture 831

14.4.1 High-Level View of the IMS Architecture 831

XX CONTENTS

14.4.2 IMS Architecture: A Closer Look 835

14.5 IMS Communication Protocols for Signaling and Media

Transport 841

14.5.1 Using SIP in IMS 842

14.5.2 H.248 in IMS 845

14.6 Identifying the IMS Subscriber and the IMS Elements 848

14.7 IMS Session Setup Scenarios 852

14.7.1 IMS Device to PSTN Call Setup: A Closer Look 852

14.7.2 PSTN-Originated and IMS Device-Terminated VoIP

Call Setup: An Overview 856

14.7.3 Multimedia Session Setup for IMS Endpoints: A Brief

Overview 858

14.8 IMS Services and Applications 860

14.9 Implementation of Quality-of-Service using IMS 862

14.10 Points to Remember 864

15 Fourth-Generation Technologies 867

15.1 Why 4G Technologies? 867

15.2 Essential Elements of 4G Technologies 869

15.3 Fundamentals of OFDM and OFDMA 871

15.3.1 OFDM and OFDMA: Why and Why Now? 871

15.3.2 OFDM: A High-Level View 872

15.3.3 Construction of Orthogonal Subcarriers 874

15.3.4 OFDM Challenges and Solutions 878

15.3.5 Simplified OFDMA Transceiver 884

15.4 Multiple Antenna Techniques 888

15.4.1 Diversity Techniques: Some Simple and Some

Sophisticated! 888

15.4.2 Spatial Multiplexing 892

15.4.3 Beamforming 893

15.4.4 Space-Division Multiple Access 895

15.5 WiMAX Overview 897

15.5.1 Salient Features of WiMAX 897

15.5.2 WiMAX Network Architecture 900

15.5.3 WiMAX Air Interface 902

15.5.4 WiMAX Operations 903

15.6 Overview of LTE 908

15.6.1 Salient Features of LTE 909

CONTENTS XXi

15.6.2 LTE Network Architecture 911

15.6.3 LTE Air Interface 914

15.6.4 LTE Operations 915

15.6.5 A Brief Overview of LTE-Advanced 919

15.7 4G Technology Challenges 921

15.8 Points to Remember 922

Appendix A: A Brief Overview of Signaling System 7 923

Appendix B: Erlang-B Table 929

Appendix C: A High-Level Comparison of Third-Generation Technologies 931

Appendix D: HSPA+ Overview 943

D. 1 Summary of HSPA+ Features 943

D.2 Data Transmission in HSPA+: A Closer Look 947

D.3 HSPA+: Beyond Release 7 952

References 955

Glossary 977

Index 991