Vijay K. Garg - St.Mary's

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WIRELESS COMMUNICATIONS AND NETWORKING

The Morgan Kaufmann Series in Networking Series Editor, David Clark, M.I.T. Wireless Communications and Networking Vijay K. Garg Ethernet Networking for the Small Office and Professional Home Office Jan L. Harrington Network Analysis, Architecture, and Design, 3e James D. McCabe IPv6 Advanced Protocols Implementation Qing Li, Tatuya Jinmei, and Keiichi Shima Computer Networks: A Systems Approach, 4e Larry L. Peterson and Bruce S. Davie Network Routing: Algorithms, Protocols, and Architectures Deepankar Medhi and Karthikeyan Ramaswami Deploying IP and MPLS QoS for Multiservice Networks: Theory and Practice John Evans and Clarence Filsfils Traffic Engineering and QoS Optimization of Integrated Voice & Data Networks Gerald R. Ash IPv6 Core Protocols Implementation Qing Li, Tatuya Jinmei, and Keiichi Shima Smart Phone and Next-Generation Mobile Computing Pei Zheng and Lionel Ni GMPLS: Architecture and Applications Adrian Farrel and Igor Bryskin Network Security: A Practical Approach Jan L. Harrington Content Networking: Architecture, Protocols, and Practice Markus Hofmann and Leland R. Beaumont Network Algorithmics: An Interdisciplinary Approach to Designing Fast Networked Devices George Varghese Network Recovery: Protection and Restoration of Optical, SONET-SDH, IP, and MPLS Jean Philippe Vasseur, Mario Pickavet, and Piet Demeester Routing, Flow, and Capacity Design in Communication and Computer Networks Michał Pióro and Deepankar Medhi Wireless Sensor Networks: An Information Processing Approach Feng Zhao and Leonidas Guibas Communication Networking: An Analytical Approach Anurag Kumar, D. Manjunath, and Joy Kuri The Internet and Its Protocols: A Comparative Approach Adrian Farrel Modern Cable Television Technology: Video, Voice, and Data Communications, 2e

Walter Ciciora, James Farmer, David Large, and Michael Adams Bluetooth Application Programming with the Java APIs C Bala Kumar, Paul J. Kline, and Timothy J. Thompson Policy-Based Network Management: Solutions for the Next Generation John Strassner MPLS Network Management: MIBs, Tools, and Techniques Thomas D. Nadeau Developing IP-Based Services: Solutions for Service Providers and Vendors Monique Morrow and Kateel Vijayananda Telecommunications Law in the Internet Age Sharon K. Black Optical Networks: A Practical Perspective, 2e Rajiv Ramaswami and Kumar N. Sivarajan Internet QoS: Architectures and Mechanisms Zheng Wang TCP/IP Sockets in Java: Practical Guide for Programmers Michael J. Donahoo and Kenneth L. Calvert TCP/IP Sockets in C: Practical Guide for Programmers Kenneth L. Calvert and Michael J. Donahoo Multicast Communication: Protocols, Programming, and Applications Ralph Wittmann and Martina Zitterbart MPLS: Technology and Applications Bruce Davie and Yakov Rekhter High-Performance Communication Networks, 2e Jean Walrand and Pravin Varaiya Internetworking Multimedia Jon Crowcroft, Mark Handley, and Ian Wakeman Understanding Networked Applications: A First Course David G. Messerschmitt Integrated Management of Networked Systems: Concepts, Architectures, and their Operational Application Heinz-Gerd Hegering, Sebastian Abeck, and Bernhard Neumair Virtual Private Networks: Making the Right Connection Dennis Fowler Networked Applications: A Guide to the New Computing Infrastructure David G. Messerschmitt Wide Area Network Design: Concepts and Tools for Optimization Robert S. Cahn For further information on these books and for a list of forthcoming titles, please visit our Web site at http://www.mkp.com.

WIRELESS COMMUNICATIONS AND NETWORKING Vijay K. Garg

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Morgan Kaufmann Publishers is an imprint of Elsevier. 500 Sansome Street, Suite 400, San Francisco, CA 94111 This book is printed on acid-free paper. © 2007 by Elsevier Inc. All rights reserved. Designations used by companies to distinguish their products are often claimed as trademarks or registered trademarks. In all instances in which Morgan Kaufmann Publishers is aware of a claim, the product names appear in initial capital or all capital letters. Readers, however, should contact the appropriate companies for more complete information regarding trademarks and registration. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopying, scanning, or otherwise—without prior written permission of the publisher. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: (⫹44) 1865 843830, fax: (⫹44) 1865 853333, E-mail: [email protected] You may also complete your request on-line via the Elsevier homepage (http://elsevier.com), by selecting “Support & Contact” then “Copyright and Permission” and then “Obtaining Permissions.” Library of Congress Cataloging-in-Publication Data Garg, Vijay Kumar, 1938Wireless communications and networking / Vijay K. Garg.–1st ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-12-373580-5 (casebound : alk. paper) ISBN-10: 0-12-373580-7 (casebound : alk. paper) 1. Wireless communication systems. 2. Wireless LANs. I. Title. TK5103.2.G374 2007 621.382’1–dc22 2006100601 ISBN: 978-0-12-373580-5 For information on all Morgan Kaufmann publications, visit our Web site at www.mkp.com or www.books.elsevier.com Printed in the United States of America 07 08 09 10 11 5 4 3 2 1

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The book is dedicated to my grandchildren — Adam, Devin, Dilan, Nevin, Monica, Renu, and Mollie.

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Contents About the Author Preface 1 An Overview of Wireless Systems

xxiii xxv 1

1.1

Introduction

1

1.2

First- and Second-Generation Cellular Systems

2

1.3

Cellular Communications from 1G to 3G

5

1.4

Road Map for Higher Data Rate Capability in 3G

8

1.5

Wireless 4G Systems

14

1.6

Future Wireless Networks

15

1.7

Standardization Activities for Cellular Systems

17

1.8

Summary

19

Problems

20

References

20

2 Teletraffic Engineering

23

2.1

Introduction

23

2.2

Service Level

23

2.3

Traffic Usage

24

2.4

Traffic Measurement Units

25

2.5

Call Capacity

30

2.6

Definitions of Terms

32

2.7

Data Collection

36

2.8

Office Engineering Considerations

36

2.9

Traffic Types

38

2.10 Blocking Formulas

39

2.10.1 Erlang B Formula

40

2.10.2 Poisson’s Formula

41

2.10.3 Erlang C Formula

41

2.10.4 Comparison of Erlang B and Poisson’s Formulas

42

2.10.5 Binomial Formula

42

vii

viii

Contents

2.11 Summary

43

Problems

44

References

45

3 Radio Propagation and Propagation Path-Loss Models

47

3.1

Introduction

3.2

Free-Space Attenuation

48

3.3

Attenuation over Reflecting Surface

50

3.4

Effect of Earth’s Curvature

53

3.5

Radio Wave Propagation

54

Characteristics of Wireless Channel

58

3.6

3.6.1 3.7

Multipath Delay Spread, Coherence Bandwidth, and Coherence Time

47

60

Signal Fading Statistics

62

3.7.1

Rician Distribution

63

3.7.2

Rayleigh Distribution

64

3.7.3

Lognormal Distribution

64

3.8

Level Crossing Rate and Average Fade Duration

65

3.9

Propagation Path-Loss Models

66

3.9.1

Okumura/Hata Model

67

3.9.2

Cost 231 Model

68

3.9.3

IMT-2000 Models

72

3.10 Indoor Path-Loss Models

75

3.11 Fade Margin

76

3.12 Link Margin

79

3.13 Summary

81

Problems

82

References

83

4 An Overview of Digital Communication and Transmission

85

4.1

Introduction

85

4.2

Baseband Systems

87

4.3

Messages, Characters, and Symbols

87

4.4

Sampling Process

88

4.4.1

Aliasing

91

4.4.2

Quantization

93

Contents

ix

4.4.3

Sources of Error

94

4.4.4

Uniform Quantization

95

4.5

Voice Communication

97

4.6

Pulse Amplitude Modulation (PAM)

4.7

Pulse Code Modulation

100

4.8

Shannon Limit

102

4.9

Modulation

103

98

4.10 Performance Parameters of Coding and Modulation Scheme

105

4.11 Power Limited and Bandwidth-Limited Channel

108

4.12 Nyquist Bandwidth

109

4.13 OSI Model

112

4.13.1 OSI Upper Layers

112

4.14 Data Communication Services

113

4.15 Multiplexing

115

4.16 Transmission Media

116

4.17 Transmission Impairments

118

4.17.1 Attenuation Distortion

118

4.17.2 Phase Distortion

118

4.17.3 Level

118

4.17.4 Noise and SNR

119

4.18 Summary

120

Problems

121

References

121

5 Fundamentals of Cellular Communications

123

5.1

Introduction

123

5.2

Cellular Systems

123

5.3

Hexagonal Cell Geometry

125

5.4

Cochannel Interference Ratio

131

5.5

Cellular System Design in Worst-Case Scenario with an Omnidirectional Antenna

134

5.6

Cochannel Interference Reduction

136

5.7

Directional Antennas in Seven-Cell Reuse Pattern

137

5.7.1

Three-Sector Case

137

5.7.2

Six-Sector Case

138

5.8

Cell Splitting

141

x

Contents

5.9

Adjacent Channel Interference (ACI)

144

5.10 Segmentation

144

5.11 Summary

145

Problems

146

References

147

6 Multiple Access Techniques

149

6.1

Introduction

149

6.2

Narrowband Channelized Systems

150

6.2.1

6.3

Frequency Division Duplex (FDD) and Time Division Duplex (TDD) System

151

6.2.2

Frequency Division Multiple Access

152

6.2.3

Time Division Multiple Access

154

Spectral Efficiency

156

6.3.1

156

Spectral Efficiency of Modulation

6.3.2

Multiple Access Spectral Efficiency

159

6.3.3

Overall Spectral Efficiency of FDMA and TDMA Systems

160

6.4

Wideband Systems

163

6.5

Comparisons of FDMA, TDMA, and DS-CDMA (Figure 6.7)

166

6.6

Capacity of DS-CDMA System

168

6.7

Comparison of DS-CDMA vs. TDMA System Capacity

171

6.8

Frequency Hopping Spread Spectrum with M-ary Frequency Shift Keying

172

Orthogonal Frequency Division Multiplexing (OFDM)

173

6.9

6.10 Multicarrier DS-CDMA (MC-DS-CDMA)

175

6.11 Random Access Methods

176

6.11.1 Pure ALOHA

176

6.11.2 Slotted ALOHA

177

6.11.3 Carrier Sense Multiple Access (CSMA)

178

6.11.4 Carrier Sense Multiple Access with Collision Detection

180

6.11.5 Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

181

6.12 Idle Signal Casting Multiple Access

184

6.13 Packet Reservation Multiple Access

184

6.14 Error Control Schemes for Link Layer

185

6.15 Summary

188

Contents

xi

Problems

189

References

190

7 Architecture of a Wireless Wide-Area Network (WWAN)

193

7.1

Introduction

193

7.2

WWAN Subsystem Entities

194

7.2.1

User Equipment

194

7.2.2

Radio Station Subsystem

196

7.2.3

Network and Switching Subsystem

197

7.2.4

Operation and Maintenance Subsystem (OMSS)

198

7.2.5

Interworking and Interfaces

199

7.3

Logical Channels

199

7.4

Channel and Frame Structure

201

7.5

Basic Signal Characteristics

203

7.6

Speech Processing

203

7.7

Power Levels in Mobile Station

208

7.8

GSM Public Land Mobile Network Services

209

7.9

Summary

212

Problems

213

References

213

8 Speech Coding and Channel Coding 8.1 8.2

8.3

215

Introduction

215

Speech Coding

215

8.2.1

Speech Coding Methods

216

8.2.2

Speech Codec Attributes

217

8.2.3

Linear-Prediction-Based Analysis-by-Synthesis (LPAS)

218

8.2.4

Waveform Coding

219

8.2.5

Vocoders

220

8.2.6

Hybrid Coding

221

Speech Codecs in European Systems

222

8.3.1

GSM Enhanced Full-Rate (EFR)

222

8.3.2

Adaptive Multiple Rate Codec

224

8.4

CELP Speech Codec

227

8.5

Enhanced Variable Rate Codec

230

8.6

Channel Coding

233

xii

Contents

8.7

8.6.1

Reed-Solomon (RS) Codes

234

8.6.2

Convolutional Code

237

8.6.3

Turbo Coding

241

8.6.4

Soft and Hard Decision Decoding

244

8.6.5

Bit-Interleaving and De-Interleaving

245

Summary

246

Problems

247

References

247

9 Modulation Schemes

249

9.1

Introduction

249

9.2

Introduction to Modulation

249

9.3

Phase Shift Keying

257

9.3.1

Quadrature Phase Shift Keying (QPSK), Offset-Quadrature Phase Shift Keying (OQPSK) and M-PSK Modulation [5,7,11]

260

9.3.2

␲/4-DQPSK Modulation

264

9.3.3

MSK and GMSK Modulation

268

9.4

Quadrature Amplitude Modulation

272

9.5

M-ary Frequency Shift Keying

275

9.6

Modulation Selection

278

9.7

Synchronization

278

9.8

Equalization

282

9.9

Summary

284

Problems

284

References

285

10 Antennas, Diversity, and Link Analysis

287

10.1 Introduction

287

10.2 Antenna System

287

10.3 Antenna Gain

288

10.4 Performance Criteria of Antenna Systems

293

10.5 Relationship between Directivity, Gain, and Beam Width of an Antenna

295

10.5.1 The Relationship between Directivity and Gain

296

10.5.2 Relation between Gain and Beam Width

297

10.5.3 Helical Antennas

298

Contents

xiii

10.6 Diversity 10.6.1 Types of Diversity 10.7 Combining Methods

300 301 302

10.7.1 Selection Combiner

303

10.7.2 Switched Combiner

306

10.7.3 Maximal Ratio Combiner

306

10.7.4 Equal Gain Combiner

309

10.8 Rake Receiver

310

10.9 Link Budgets

312

10.10 Summary

314

Problems

315

References

315

11 Spread Spectrum (SS) and CDMA Systems

317

11.1 Introduction

317

11.2 Concept of Spread Spectrum

317

11.3 System Processing Gain

321

11.4 Requirements of Direct-Sequence Spread Spectrum

328

11.5 Frequency-Hopping Spread Spectrum Systems

329

11.6 Operational Advantages of SS Modulation

333

11.7 Coherent Binary Phase-Shift Keying DSSS

335

11.8 Quadrature Phase-Shift Keying DSSS

337

11.9 Bit Scrambling

339

11.10 Requirements of Spreading Codes

341

11.11 Multipath Path Signal Propagation and Rake Receiver

342

11.12 Critical Challenges of CDMA

347

11.13 TIA IS-95 CDMA System

347

11.13.1 Downlink (Forward) (BS to MS)

348

11.13.2 Uplink (Reverse) (MS to BS)

351

11.14 Power Control in CDMA 11.14.1 Open Loop Power Control

356 357

11.15 Softer and Soft Handoff

361

11.16 Summary

364

Problems

364

References

366

xiv

Contents

12 Mobility Management in Wireless Networks

369

12.1 Introduction

369

12.2 Mobility Management Functions

370

12.3 Mobile Location Management

371

12.3.1 Mobility Model 12.4 Mobile Registration

372 376

12.4.1 GSM Token-Based Registration

379

12.4.2 IMSI Attach and IMSI Detach (Registration and Deregistration) in GSM

381

12.4.3 Paging in GSM

381

12.5 Handoff

384

12.5.1 Handoff Techniques

386

12.5.2 Handoff Types

387

12.5.3 Handoff Process and Algorithms

387

12.5.4 Handoff Call Flows

389

12.6 Summary

393

Problems

394

References

394

13 Security in Wireless Systems

397

13.1 Introduction

397

13.2 Security and Privacy Needs of a Wireless System

399

13.2.1 Purpose of Security

399

13.2.2 Privacy Definitions

399

13.2.3 Privacy Requirements

400

13.2.4 Theft Resistance Requirements

402

13.2.5 Radio System Requirements

403

13.2.6 System Lifetime Requirements

404

13.2.7 Physical Requirements

404

13.2.8 Law Enforcement Requirements

405

13.3 Required Features for a Secured Wireless Communications System

407

13.4 Methods of Providing Privacy and Security in Wireless Systems

407

13.5 Wireless Security and Standards

409

13.6 IEEE 802.11 Security

409

13.7 Security in North American Cellular/PCS Systems

411

13.7.1 Shared Secret Data Update

412

Contents

xv

13.7.2 Global Challenge

412

13.7.3 Unique Challenge

414

13.8 Security in GSM, GPRS, and UMTS

415

13.8.1 Security in GSM

415

13.8.2 Security in GPRS

417

13.8.3 Security in UMTS

419

13.9 Data Security

420

13.9.1 Firewalls

420

13.9.2 Encryption

421

13.9.3 Secure Socket Layer

427

13.9.4 IP Security Protocol (IPSec)

427

13.9.5 Authentication Protocols

427

13.10 Air Interface Support for Authentication Methods

429

13.11 Summary of Security in Current Wireless Systems

430

13.11.1 Billing Accuracy

431

13.11.2 Privacy of Information

431

13.11.3 Theft Resistance of MS

431

13.11.4 Handset Design

431

13.11.5 Law Enforcement

431

13.12 Summary

432

Problems

432

References

433

14 Mobile Network and Transport Layer

435

14.1 Introduction

435

14.2 Concept of the Transmission Control Protocol/Internet Protocol Suite in Internet

436

14.3 Network Layer in the Internet

439

14.3.1 Internet Addresses

441

14.3.2 IP Adjunct Protocols

442

14.3.3 QoS Support in the Internet

443

14.4 TCP/IP Suite

446

14.5 Transmission Control Protocol

448

14.5.1 TCP Enhancements for Wireless Networks

452

14.5.2 Implementation of Wireless TCP

455

14.6 Mobile IP (MIP) and Session Initiation Protocol (SIP)

457

xvi

Contents

14.6.1 Mobile IP

458

14.6.2 Session Initiation Protocol (SIP)

464

14.7 Internet Reference Model

464

14.8 Summary

465

Problems

465

References

466

15 Wide-Area Wireless Networks (WANs) — GSM Evolution

469

15.1 Introduction

469

15.2 GSM Evolution for Data

470

15.2.1 High Speed Circuit Switched Data

472

15.2.2 General Packet Radio Service

473

15.2.3 Enhanced Data Rates for GSM Enhancement

483

15.3 Third-Generation (3G) Wireless Systems

489

15.4 UMTS Network Reference Architecture

495

15.5 Channel Structure in UMTS Terrestrial Radio Access Network

497

15.6 Spreading and Scrambling in UMTS

504

15.7 UMTS Terrestrial Radio Access Network Overview 15.7.1 UTRAN Logical Interfaces 15.7.2 Distribution of UTRAN Functions 15.8 UMTS Core Network Architecture

506 508 516 518

15.8.1 3G-MSC

520

15.8.2 3G-SGSN

520

15.8.3 3G-GGSN

521

15.8.4 SMS-GMSC/SMS-IWMSC

522

15.8.5 Firewall

522

15.8.6 DNS/DHCP

522

15.9 Adaptive Multi-Rate Codec for UMTS

523

15.10 UMTS Bearer Service

524

15.11 QoS Management

526

15.11.1 Functions for UMTS Bearer Service in the Control Plane

526

15.11.2 Functions for UMTS Bearer Service in the User Plane

527

15.12 Quality of Service in UMTS

528

15.12.1 QoS Classes

528

15.12.2 QoS Attributes

528

15.13 High-Speed Downlink Packet Access (HSDPA)

530

Contents

xvii

15.14 Freedom of Mobile multimedia Access (FOMA)

536

15.15 Summary

537

Problems

538

References

539

16 Wide-Area Wireless Networks — cdmaOne Evolution

541

16.1 Introduction

541

16.2 cdma2000 Layering Structure

544

16.2.1 Upper Layer

544

16.2.2 Lower Layers

545

16.3 Forward Link Physical Channels of cdma2000

550

16.4 Forward Link Features

553

16.4.1 Transmit Diversity

553

16.4.2 Orthogonal Modulation

555

16.4.3 Power Control

556

16.4.4 Walsh Code Administration

558

16.4.5 Modulation and Spreading

558

16.5 Reverse Link Physical Channels of cdma2000 16.5.1 Reverse Link Power Control 16.6 Evolution of cdmaOne (IS-95) to cdma2000

562 565 568

16.6.1 cdma2000 1X EV-DO

574

16.6.2 cdma2000 1X EV-DV

581

16.7 Technical Differences between cdma2000 and WCDMA

586

16.8 Summary

587

Problems

592

References

592

17 Planning and Design of Wide-Area Wireless Networks

595

17.1 Introduction

595

17.2 Planning and Design of a Wireless Network

596

17.3 Radio Design for a Cellular Network

600

17.3.1 Radio Link Design

600

17.3.2 Coverage Planning

601

17.4 Receiver Sensitivity and Link Budget

602

17.4.1 Link Budget for the GSM1800 System

602

17.4.2 Pole Capacity of a CDMA Cell

605

xviii

Contents

17.4.3 Uplink Radio Link Budget for a CDMA System

606

17.4.4 Downlink Radio Link Budget for a CDMA System

609

17.5 cdma2000 1X EV-DO

615

17.5.1 1X EV-DO Concept

615

17.5.2 Details of cdma2000 1X EV-DO

617

17.6 High-Speed Downlink Packet Access 17.6.1 HSDPA SINR Calculation

620 623

17.7 Iub Interface Dimensioning

624

17.8 Radio Network Controller Dimensioning

624

17.9 Summary

626

Problems

626

References

629

18 Wireless Application Protocol

631

18.1 Introduction

631

18.2 WAP and the World Wide Web (WWW)

631

18.3 Introduction to Wireless Application Protocol

632

18.4 The WAP Programming Model

633

18.4.1 The WWW Model

634

18.4.2 The WAP Model

634

18.5 WAP Architecture

636

18.5.1 Wireless Application Environment

637

18.5.2 Wireless Telephony Application

638

18.5.3 Wireless Session Protocol

639

18.5.4 Wireless Transaction Protocol

640

18.5.5 Wireless Transport Layer Security

641

18.5.6 Wireless Datagram Protocol

641

18.5.7 Optimal WAP Bearers

642

18.6 Traditional WAP Networking Environment

643

18.7 WAP Advantages and Disadvantages

645

18.8 Applications of WAP

646

18.9 imode

647

18.10 imode versus WAP

649

18.11 Summary

650

Problems

650

References

650

Contents

xix

19 Wireless Personal Area Network — Bluetooth

653

19.1 Introduction

653

19.2 The Wireless Personal Area Network

654

19.3 Bluetooth (IEEE 802.15.1)

656

19.4 Definitions of the Terms Used in Bluetooth

659

19.5 Bluetooth Protocol Stack

660

19.5.1 Transport Protocol Group

660

19.5.2 Middleware Protocol Group

661

19.5.3 Application Group

663

19.6 Bluetooth Link Types

663

19.7 Bluetooth Security

666

19.7.1 Security Levels

667

19.7.2 Limitations of Bluetooth Security

669

19.8 Network Connection Establishment in Bluetooth

669

19.9 Error Correction in Bluetooth

670

19.10 Network Topology in Bluetooth

671

19.11 Bluetooth Usage Models

671

19.12 Bluetooth Applications

672

19.13 WAP and Bluetooth

673

19.14 Summary

673

Problems

673

References

674

20 Wireless Personal Area Networks: Low Rate and High Rate

675

20.1 Introduction

675

20.2 Wireless Sensor Network

675

20.3 Usage of Wireless Sensor Networks

678

20.4 Wireless Sensor Network Model

678

20.5 Sensor Network Protocol Stack

683

20.5.1 Physical Layer

683

20.5.2 Data Link Layer

684

20.5.3 Network Layer

685

20.5.4 Transport Layer

687

20.5.5 Application Layer

687

20.5.6 Power, Mobility, and Task Management Planes

688

xx

Contents

20.6 ZigBee Technology 20.6.1 ZigBee Components and Network Topologies 20.7 IEEE 802.15.4 LR-WPAN Device Architecture

688 689 691

20.7.1 Physical Layer

692

20.7.2 Data Link Layer

694

20.7.3 The Network Layer

697

20.7.4 Applications

702

20.8 IEEE 802.15.3a — Ultra WideBand

703

20.9 Radio Frequency Identification

707

20.10 Summary

710

Problems

710

References

711

21 Wireless Local Area Networks

713

21.1 Introduction

713

21.2 WLAN Equipment

716

21.3 WLAN Topologies

717

21.4 WLAN Technologies

719

21.4.1 Infrared Technology

719

21.4.2 UHF Narrowband Technology

719

21.4.3 Spread Spectrum Technology

721

21.5 IEEE 802.11 WLAN

721

21.5.1 IEEE 802.11 Architecture

722

21.5.2 802.11 Physical Layer (PHY)

723

21.5.3 IEEE 802.11 Data Link Layer

735

21.5.4 IEEE 802.11 Medium Access Control

736

21.5.5 IEEE 802.11 MAC Sublayer

742

21.6 Joining an Existing Basic Service Set

744

21.7 Security of IEEE 802.11 Systems

747

21.8 Power Management

747

21.9 IEEE 802.11b — High Rate DSSS

748

21.10 IEEE 802.11n

749

21.11 Other WLAN Standards

752

21.11.1 HIPERLAN Family of Standards

752

21.11.2 Multimedia Access Communication — High Speed Wireless Access Network

758

Contents

xxi

21.12 Performance of a Bluetooth Piconet in the Presence of IEEE 802.11 WLANs

759

21.12.1 Packet Error Rate (PER) from N Neighboring Bluetooth Piconets

760

21.12.2 PER from M Neighboring IEEE 802.11 WLANs

761

21.12.3 Aggregated Throughput

762

21.13 Interference between Bluetooth and IEEE 802.11

763

21.14 IEEE 802.16

765

21.15 World Interoperability for MicroAccess, Inc. (WiMAX)

767

21.15.1 WiMAX Physical Layer (PHY)

770

21.15.2 WiMAX Media Access Control (MAC)

771

21.15.3 Spectrum Allocation for WiMAX

772

21.16 Summary

772

Problems

774

References

775

Appendix A

777

Acronyms

787

Index

806

The following Bonus Chapters can be found on the book’s website at http://books.elsevier.com/9780123735805: 22 Interworking between Wireless Local Area Networks and 3G Wireless Wide Area Networks

22-1

22.1 Introduction

22-1

22.2 Interworking Objectives and Requirements

22-2

22.3 Interworking Schemes to Connect WLANs and 3G Networks

22-3

22.4 De Facto WLAN System Architecture

22-5

22.5 Session Mobility

22-7

22.6 Interworking Architectures for WLAN and GPRS

22-8

22.7 System Description with Tight Coupling

22-9

22.7.1 Protocol Stack

22-12

22.7.2 WLAN Adaptation Function

22-13

22.7.3 GIF/RAI Discovery Procedure

22-15

22.8 System Description with Loose Coupling

22-17

xxii

Contents

22.8.1 Authentication

22-20

22.8.2 User Data Routing and Access to Services

22-23

22.8.3 3GPP-based Charging for WLAN

22-23

22.8.4 Session Mobility

22-26

22.9 Local Multipoint Distribution Service

22-26

22.10 Multichannel Multipoint Distribution System

22-29

22.11 Summary

22-31

Problems

22-32

References

22-32

23 Fourth Generation Systems and New Wireless Technologies

23-1

23.1 Introduction

23-1

23.2 4G Vision

23-2

23.3 4G Features and Challenges

23-3

23.4 Applications of 4G

23-7

23.5 4G Technologies

23-7

23.5.1 Multicarrier Modulation

23-7

23.5.2 Smart Antenna Techniques

23-10

23.5.3 OFDM-MIMO Systems

23-14

23.5.4 Adaptive Modulation and Coding with Time-Slot Scheduler

23-14

23.5.5 Bell Labs Layered Space Time (BLAST) System

23-15

23.5.6 Software-Defined Radio

23-18

23.5.7 Cognitive Radio

23-20

23.6 Summary

23-21

Problems

23-21

References

23-22

Appendix B

Path Loss over a Reflecting Surface

B-1

Appendix C

Error Functions

C-1

Appendix D

Spreading Codes Used in CDMA

D-1

Appendix E

Power Units

E-1

About the Author Vijay K. Garg has been a professor in the Electrical and Computer Engineering Department at the University of Illinois at Chicago since 1999, where he teaches graduate courses in Wireless Communications and Networking. Dr. Garg was a Distinguished Member of Technical Staff at the Lucent Technologies Bell Labs in Naperville, Illinois from 1985 to 2001. He received his Ph.D. degree from the Illinois Institute of Technologies, Chicago, IL in 1973 and his MS degree from the University of California at Berkeley, CA in 1966. Dr. Garg has co-authored several technical books including five in wireless communications. He is a Fellow of ASCE and ASME, and a Senior Member of IEEE. Dr. Garg is a registered Professional Engineer in the state of Maine and Illinois. He is an Academic Member of the Russian Academy of Transport. Dr. Garg was a Feature Editor of Wireless/ PCS Series in IEEE Communication Magazine from 1996–2001.

xxiii

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Preface During the past three decades, the world has seen significant changes in the telecommunications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from first-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wireless personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs). With the Internet and corporate intranets becoming essential parts of daily business activities, it has become increasingly advantageous to have wireless offices that can connect mobile users to their enterprises. The potential for technologies that deliver news and other business-related information directly to mobile devices could also develop entirely new revenue streams for service providers. The 3G mobile systems are expected to provide worldwide access and global roaming for a wide range of services. The 3G WWANs are designed to support data rates up to 144 kbps with comprehensive coverage and up to 2 Mbps for selected local areas. Prior to the emergence of 3G services, mobile data networks such as general packet radio service (GPRS) over time division multiple-access (TDMA) systems and high-speed packet data over IS-95 code-division multiple access (CDMA) systems were already very popular. At the same time, after the introduction of Bluetooth and imode technology in 1998, local broadband and ad hoc wireless networks attracted a great deal of attention. This sector of the wireless networking industry includes the traditional WLANs and the emerging WPANs. Multi hop wireless ad hoc networks complement the existing WLAN standards like IEEE 802.11a/b/g/n and Bluetooth to allow secure, reliable wireless communications among all possible hand-held devices such as personal digital assistances (PDAs), cell-phones, laptops, or other portable devices that have a wireless communication interface. Ad hoc networks are not dependent on a single point of attachment. The routing protocols for ad hoc networks are designed to self-configure and self-organize the networks to seamlessly create an access point on the fly as a user or device moves. Provisioning data services over the wireless data networks including ad hoc networks requires smart data management protocols and new transaction models for data delivery and transaction processing, respectively. While personalization of data services is desired, over personalization will have ramifications on scalability of wireless networks? As such, mobile computing not only poses challenges but also opens up an interesting research area. It is redefining existing business models xxv

xxvi

Preface

and creating entirely new ones. Envisioning new business processes vis-à-vis the enabling technologies is also quite interesting. Over the past decade, wireless data networking has developed into its own discipline. There is no doubt that the evolution of wireless networks has had significant impact on our lifestyle. This book is designed to provide a unified foundation of principles for data-oriented wireless networking and mobile communications. This book is an extensive enhancement to the Wireless & Personal Communications book published by Prentice Hall in 1996, which primarily addressed 2G cellular networks. Since then, wireless technologies have undergone significant changes; new and innovative techniques have been introduced, the focus of wireless communications is increasingly changing from mobile voice applications to mobile data and multimedia applications. Wireless technology and computing have come closer and closer to generating a strong need to address this issue. In addition, wireless networks now include wide area cellular networks, wireless local area networks, wireless metropolitan area networks, and wireless personal area networks. This book addresses these networks in extensive detail. The book primarily discusses wireless technologies up to 3G but also provides some insight into 4G technologies. It is indeed a challenge to provide an over-arching synopsis for mobile data networking and mobile communications for diverse audiences including managers, practicing engineers, and students who need to understand this industry. My basic motivation in writing this book is to provide the details of mobile data networking and mobile communications under a single cover. In the last two decades, many books have been written on the subject of wireless communications and networking. However, mobile data networking and mobile communications were not fully addressed. This book is written to provide essentials of wireless communications and wireless networking including WPAN, WLAN, WMAN, and WWAN. The book is designed for practicing engineers, as well as senior/first-year graduate students in Electrical and Computer Engineering (ECE), and Computer Science (CS). The first thirteen chapters of the book focus on the fundamentals that are required to study mobile data networking and mobile communications. Numerous solved examples have been included to show applications of theoretical concepts. In addition, unsolved problems are given at the end of each chapter for practice. After introducing fundamental concepts, the book focuses on mobile networking aspects with several chapters devoted to the discussion of WPAN, WLAN, WWAN, and other aspects of mobile communications such as mobility management, security, and cellular network planning. Two additional “Bonus” chapters on inter-working between WLAN and WWAN and on 4G systems (along with several helpful appendices) are available free on the book’s website at http://books. elsevier.com/9780123735805.

Preface

xxvii

Most of the books in wireless communications and networking appear to ignore the standard activities in the field. I feel students in wireless networking must be exposed to various standard activities. I therefore address important standard activities including 3GPP, 3GPP2, IEEE 802.11, IEEE 802.15 and IEEE 802.16 in the book. This feature of the book is also very beneficial to the professionals who wish to know about a particular standard without going through the voluminous material on that standard. A unique feature of this book that is missing in most of the available books on wireless communications and networking is to offer a balance between theoretical and practical concepts. This book can be used to teach two semester courses in mobile data networking and mobile communications to ECE and CS students. Chapter 4 may be omitted for ECE students and Chapter 14 for CS students. The first course — Introduction to Wireless Communications and Networking can be offered to senior undergraduate and first year graduate students. This should include first fourteen chapters. Chapters 4 and 14 may be omitted depending on the students’ background. The second course — Wireless Data Networking should include Chapters 15 through 23. The first course should be a pre-requisite to the second course. The student should be given homework, two examinations, and a project to complete each course. In addition, this book can also be used to teach a comprehensive course in Wireless Data Networking to IT professionals by using Chapters 2, 3, 5, 6, 7, 11, 15, 16, and 18 to 22. During the preparation of this manuscript my family members were very supportive. I would like to thank my children, Nina, Meena, and Ravi. Also, I appreciate the support given by my wife, Pushpa. In addition, I appreciate the support of the reviewers, Elaine Cheong, Frank Farrante, and Pei Zhang in providing valuable comments on the manuscript. Finally, I am thankful of Rachel Roumeliotis for coordinating the reviews of the manuscript. Vijay K. Garg Willowbrook, IL

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CHAPTER 1 An Overview of Wireless Systems 1.1

Introduction

The cellular system employs a different design approach than most commercial radio and television systems use [1,2]. Radio and television systems typically operate at maximum power and with the tallest antennas allowed by the regulatory agency of the country. In the cellular system, the service area is divided into cells. A transmitter is designed to serve an individual cell. The system seeks to make efficient use of available channels by using low-power transmitters to allow frequency reuse at much smaller distances. Maximizing the number of times each channel can be reused in a given geographic area is the key to an efficient cellular system design. During the past three decades, the world has seen significant changes in the telecommunications industry. There have been some remarkable aspects to the rapid growth in wireless communications, as seen by the large expansion in mobile systems. Wireless systems consist of wireless wide-area networks (WWAN) [i.e., cellular systems], wireless local area networks (WLAN) [4], and wireless personal area networks (WPAN) (see Figure 1.1) [17]. The handsets used in all of these systems possess complex functionality, yet they have become small, lowpower consuming devices that are mass produced at a low cost, which has in turn accelerated their widespread use. The recent advancements in Internet technology have increased network traffic considerably, resulting in a rapid growth of data rates. This phenomenon has also had an impact on mobile systems, resulting in the extraordinary growth of the mobile Internet. Wireless data offerings are now evolving to suit consumers due to the simple reason that the Internet has become an everyday tool and users demand data mobility. Currently, wireless data represents about 15 to 20% of all air time. While success has been concentrated in vertical markets such as public safety, health care, and transportation, the horizontal market (i.e., consumers) for wireless data is growing. In 2005, more than 20 million people were using wireless e-mail. The Internet has changed user expectations of what data access means. The ability to retrieve information via the Internet has been “an amplifier of demand” for wireless data applications. More than three-fourths of Internet users are also wireless users and a mobile subscriber is four times more likely to use the Internet than a nonsubscriber to 1

2

1

Short Range: Low Power, Wireless Personal Area Network (WPAN) Bluetooth (1 Mbps) Ultra Wideband (UWB) (100 Mbps) Sensor Networks IEEE 802.15.4, Zigbee

An Overview of Wireless Systems

Long Distance: High Power, Wireless Wide Area Networks (WWAN) 2G GSM (9.6 kbps) PDC GPRS (114 kbps) PHS (64 kbps, up to 128 kbps 3G (cdma2000, WCDMA) (384 kbps to 2 Mbps)

Middle Range: Medium Power, Wireless Local Area Network (WLAN) Home RF (10 Mbps) IEEE802.11a,b,g (108 Mbps) [802.11a based proprietary 2x mode]

PDC: Personal Digital Cellular (Japan) GPRS: General Packet Radio Service PHS: Personal Handy Phone System (Japan)

Figure 1.1

Wireless networks.

mobile services. Such keen interest in both industries is prompting user demand for converged services. With more than a billion Internet users expected by 2008, the potential market for Internet-related wireless data services is quite large. In this chapter, we discuss briefly 1G, 2G, 2.5G, and 3G cellular systems and outline the ongoing standard activities in Europe, North America, and Japan. We also introduce broadband (4G) systems (see Figure 1.2) aimed on integrating WWAN, WLAN, and WPAN. Details of WWAN, WLAN, and WPAN are given in Chapters 15 to 20.

1.2

First- and Second-Generation Cellular Systems

The first- and second-generation cellular systems are the WWAN. The first public cellular telephone system (first-generation, 1G), called Advanced Mobile Phone System (AMPS) [8,21], was introduced in 1979 in the United States. During the early 1980s, several incompatible cellular systems (TACS, NMT, C450, etc.) were introduced in Western Europe. The deployment of these incompatible systems resulted in mobile phones being designed for one system that could not be used with another system, and roaming between the many countries of Europe was not possible. The first-generation systems were designed for voice applications. Analog frequency modulation (FM) technology was used for radio transmission. In 1982, the main governing body of the European post telegraph and telephone (PTT), la Conférence européenne des Administrations des postes et des

1.2

First- and Second-Generation Cellular Systems

Spectral Efficiency

0.30 bps/Hz

0.15 bps/Hz Max. rate 64kbps

Max. rate 2 Mbps

TDMA & CDMA

TDMA, CDMA and WCDMA

FDMA 1G Analog

AMPS TACS NMT C-450

2G Digital modulation Convolution coding Power control

2.5G/3G Hierarchal cell structure Turbo-coding

PDC GSM HSCSD GPRS IS-54/IS-136 IS-95/IS-95A/IS-95B PHS

3

3 4 bps/Hz (targeted) Max. rate ~ 200 Mbps WCDMA 4G Smart antennas? MIMO? Adaptive system OFDM modulation

EDGE cdma2000 WCDMA/UMTS 3G 1X EV-DO 3G 1X EV-DV

PHS: Personal handy phone system (Japan) MIMO: Multi-input and multi-output OFDM: Orthogonal Frequency Division Multiple Access

Figure 1.2

Wireless network from 1G to 4G.

télécommunications (CEPT), set up a committee known as Groupe Special Mobile (GSM) [9], under the auspices of its Committee on Harmonization, to define a mobile system that could be introduced across western Europe in the 1990s. The CEPT allocated the necessary duplex radio frequency bands in the 900 MHz region. The GSM (renamed Global System for Mobile communications) initiative gave the European mobile communications industry a home market of about 300 million subscribers, but at the same time provided it with a significant technical challenge. The early years of the GSM were devoted mainly to the selection of radio technologies for the air interface. In 1986, field trials of different candidate systems proposed for the GSM air interface were conducted in Paris. A set of criteria ranked in the order of importance was established to assess these candidates. The interfaces, protocols, and protocol stacks in GSM are aligned with the Open System Interconnection (OSI) principles. The GSM architecture is an open architecture which provides maximum independence between network elements (see Chapter 7) such as the Base Station Controller (BSC), the Mobile Switching Center (MSC), the Home Location Register (HLR), etc. This approach simplifies the design, testing, and implementation of the system. It also favors an evolutionary growth path, since network element independence implies that modification to one network element can be made with minimum or no impact on the others. Also, a system operator has the choice of using network elements from different manufacturers.

4

1

An Overview of Wireless Systems

GSM 900 (i.e., GSM system at 900 MHz) was adopted in many countries, including the major parts of Europe, North Africa, the Middle East, many east Asian countries, and Australia. In most of these cases, roaming agreements exist to make it possible for subscribers to travel within different parts of the world and enjoy continuity of their telecommunications services with a single number and a single bill. The adaptation of GSM at 1800 MHz (GSM 1800) also spreads coverage to some additional east Asian countries and some South American countries. GSM at 1900 MHz (i.e., GSM 1900), a derivative of GSM for North America, covers a substantial area of the United States. All of these systems enjoy a form of roaming, referred to as Subscriber Identity Module (SIM) roaming, between them and with all other GSM-based systems. A subscriber from any of these systems could access telecommunication services by using the personal SIM card in a handset suitable to the network from which coverage is provided. If the subscriber has a multiband phone, then one phone could be used worldwide. This globalization has positioned GSM and its derivatives as one of the leading contenders for offering digital cellular and Personal Communications Services (PCS) worldwide. A PCS system offers multimedia services (i.e., voice, data, video, etc.) at any time and any where. With a three band handset (900, 1800, and 1900 MHz), true worldwide seamless roaming is possible. GSM 900, GSM 1800, and GSM 1900 are second-generation (2G) systems and belong to the GSM family. Cordless Telephony 2 (CT2) is also a 2G system used in Europe for low mobility. Two digital technologies, Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA) (see Chapter 6 for details) [10] emerged as clear choices for the newer PCS systems. TDMA is a narrowband technology in which communication channels on a carrier frequency are apportioned by time slots. For TDMA technology, there are three prevalent 2G systems: North America TIA/ EIA/IS-136, Japanese Personal Digital Cellular (PDC), and European Telecommunications Standards Institute (ETSI) Digital Cellular System 1800 (GSM 1800), a derivative of GSM. Another 2G system based on CDMA (TIA/EIA/IS-95) is a direct sequence (DS) spread spectrum (SS) system in which the entire bandwidth of the carrier channel is made available to each user simultaneously (see Chapter 11 for details). The bandwidth is many times larger than the bandwidth required to transmit the basic information. CDMA systems are limited by interference produced by the signals of other users transmitting within the same bandwidth. The global mobile communications market has grown at a tremendous pace. There are nearly one billion users worldwide with two-thirds being GSM users. CDMA is the fastest growing digital wireless technology, increasing its worldwide subscriber base significantly. Today, there are already more than 200 million CDMA subscribers. The major markets for CDMA technology are North America, Latin America, and Asia, in particular Japan and Korea. In total, CDMA has been adopted by almost 50 countries around the world. The reasons behind the success of CDMA are obvious. CDMA is an advanced digital cellular technology, which can offer six to eight times the capacity of analog

1.3

Cellular Communications from 1G to 3G

5

technologies (AMP) and up to four times the capacity of digital technologies such as TDMA. The speech quality provided by CDMA systems is far superior to any other digital cellular system, particularly in difficult RF environments such as dense urban areas and mountainous regions. In both initial deployment and long-term operation, CDMA provides the most cost effective solution for cellular operators. CDMA technology is constantly evolving to offer customers new and advanced services. The mobile data rates offered through CDMA phones have increased and new voice codecs provide speech quality close to the fixed wireline. Internet access is now available through CDMA handsets. Most important, the CDMA network offers operators a smooth migration path to third-generation (3G) mobile systems, [3,5,7,11].

1.3

Cellular Communications from 1G to 3G

Mobile systems have seen a change of generation, from first to second to third, every ten years or so (see Figure 1.3). At the introduction of 1G services, the mobile device was large in size, and would only fit in the trunk of a car. All analog components such as the power amplifier, synthesizer, and shared antenna equipment were bulky. 1G systems were intended to provide voice service and low rate (about 9.6 kbps) circuit-switched data services. Miniaturization of mobile devices progressed before the introduction of 2G services (1990) to the point where the size of mobile phones fell below 200 cubic centimeters (cc). The first-generation handsets provided poor voice quality, low talk-time, and low

2G

3G

PDC

ARIB (WCDMA)

TDD

WCDMA

Direct Spreading

3G 2G

FDD

WCDMA/UMTS

GSM

GPRS EDGE 2.5G

1G

2G

AMPS

IS-54

UWC-136

IS-136 IS-136

cdma2000 1x

IS-95/95A IS-95B

Figure 1.3

3G

Cellular networks (WWAN) evolution from 1G to 3G.

Multiple Carriers CDMA

6

1

An Overview of Wireless Systems

standby time. The 1G systems used Frequency Division Multiple Access (FDMA) technology (see Chapter 6) and analog frequency modulation [8,20]. The 2G systems based on TDMA and CDMA technologies [6] were primarily designed to improve voice quality and provide a set of rich voice features. These systems supported low rate data services (16–32 kbps). For second-generation systems three major problems impacting system cost and quality of service remained unsolved. These include what method to use for band compression of voice, whether to use a linear or nonlinear modulation scheme, and how to deal with the issue of multipath delay spread caused by multipath propagation of radio waves in which there may not only be phase cancellation but also a significant time difference between the direct and reflected waves. The swift progress in Digital Signal Processors (DSPs) was probably fueled by the rapid development of voice codecs for mobile environments that dealt with errors. Large increases in the numbers of cellular subscribers and the worries of exhausting spectrum resources led to the choice of linear modulation systems. To deal with multipath delay spread, Europe, the United States, and Japan took very different approaches. Europe adopted a high transmission rate of 280 kbps per 200 kHz RF channel in GSM [13,14] using a multiplexed TDMA system with 8 to 16 voice channels, and a mandatory equalizer with a high number of taps to overcome inter-symbol interference (ISI) (see Chapter 3). The United States used the carrier transmission rate of 48 kbps in 30 kHz channel, and selected digital advanced mobile phone (DAMP) systems (IS-54/IS-136) to reduce the computational requirements for equalization, and the CDMA system (IS-95) to avoid the need for equalization. In Japan the rate of 42 kbps in 25 kHz channel was used, and equalizers were made optional. Taking into account the limitations imposed by the finite amount of radio spectrum available, the focus of the third-generation (3G) mobile systems has been on the economy of network and radio transmission design to provide seamless service from the customers’ perspective. The third-generation systems provide their users with seamless access to the fixed data network [18,19]. They are perceived as the wireless extension of future fixed networks, as well as an integrated part of the fixed network infrastructure. 3G systems are intended to provide multimedia services including voice, data, and video. One major distinction of 3G systems relative to 2G systems is the hierarchical cell structure designed to support a wide range of multimedia broadband services within the various cell types by using advanced transmission and protocol technologies. The 2G systems mainly use one-type cell and employ frequency reuse within adjacent cells in such a way that each single cell manages its own radio zone and radio circuit control within the mobile network, including traffic management and handoff procedures. The traffic supported in each cell is fixed because of frequency limitations and little flexibility of radio transmission which is mainly optimized for voice and low data rate transmissions. Increasing

1.3

Cellular Communications from 1G to 3G

7

traffic leads to costly cellular reconfiguration such as cell splitting and cell sectorization. The multilayer cell structure in 3G systems aims to overcome these problems by overlaying, discontinuously, pico- and microcells over the macrocell structure with wide area coverage. Global/satellite cells can be used in the same sense by providing area coverage where macrocell constellations are not economical to deploy and/or support long distance traffic. With low mobility and small delay spread profiles in picocells, high bit rates and high traffic densities can be supported with low complexity as opposed to low bit rates and low traffic load in macrocells that support high mobility. The user expectation will be for service selected in a uniform manner with consistent procedures, irrespective of whether the means of access to these services is fixed or mobile. Freedom of location and means of access will be facilitated by smart cards to allow customers to register on different terminals with varying capabilities (speech, multimedia, data, short messaging). The choice of a radio interface parameter set corresponding to a multiple access scheme is a critical issue in terms of spectral efficiency, taking into account the everincreasing market demand for mobile communications and the fact that radio spectrum is a very expensive and scarce resource. A comparative assessment of several different schemes was carried out in the framework of the Research in Advanced Communications Equipment (RACE) program. One possible solution is to use a hybrid CDMA/TDMA/FDMA technique by integrating advantages of each and meeting the varying requirements on channel capacity, traffic load, and transmission quality in different cellular/PCS layouts. Disadvantages of such hybrid access schemes are the high-complexity difficulties in achieving simplified low-power, low-cost transceiver design as well as efficient flexibility management in the several cell layers. CDMA is the selected approach for 3G systems by the ETSI, ARIB (Association of Radio Industries and Business — Japan) and Telecommunications Industry Association (TIA). In Europe and Japan, Wideband CDMA (WCDMA/UMTS [Universal Mobile Telecommunication Services]) was selected to avoid IS-95 intellectual property rights. In North America, cdma2000 uses a CDMA air-interface based on the existing IS-95 standard to provide wireline quality voice service and high speed data services at 144 kbps for mobile users, 384 kbps for pedestrians, and 2 Mbps for stationary users. The 64 kbps data capability of CDMA IS-95B provides high speed Internet access in a mobile environment, a capability that cannot be matched by other narrowband digital technologies. Mobile data rates up to 2 Mbps are possible using wide band CDMA technologies. These services are provided without degrading the systems’ voice transmission capabilities or requiring additional spectrum. This has tremendous implications for the majority of operators that are spectrum constrained. In the meantime, DSPs have improved in speed by an order of magnitude in each generation, from 4 MIPs (million instructions per second) through 40 MIPs to 400 MIPs.

8

1

An Overview of Wireless Systems

Since the introduction of 2G systems, the base station has seen the introduction of features such as dynamic channel assignment. In addition, most base stations began making shared use of power amplifiers and linear amplifiers whether or not modulation was linear. As such there has been an increasing demand for high-efficiency, large linear power amplifiers instead of nonlinear amplifiers. At the beginning of 2G, users were fortunate if they were able to obtain a mobile device below 150 cc. Today, about 10 years later, mobile phone size has reached as low as 70 cc. Furthermore, the enormous increase in very large system integration (VLSI) and improved CPU performance has led to increased functionality in the handset, setting the path toward becoming a small-scale computer.

1.4

Road Map for Higher Data Rate Capability in 3G

The first- and second-generation cellular systems were primarily designed for voice services and their data capabilities were limited. Wireless systems have since been evolving to provide broadband data rate capability as well. GSM is moving forward to develop cutting-edge, customer-focused solutions to meet the challenges of the 21st century and 3G mobile services. When GSM was first designed, no one could have predicted the dramatic growth of the Internet and the rising demand for multimedia services. These developments have brought about new challenges to the world of GSM. For GSM operators, the emphasis is now rapidly changing from that of instigating and driving the development of technology to fundamentally enable mobile data transmission to that of improving speed, quality, simplicity, coverage, and reliability in terms of tools and services that will boost mass market take-up. People are increasingly looking to gain access to information and services whenever they want from wherever they are. GSM will provide that connectivity. The combination of Internet access, web browsing, and the whole range of mobile multimedia capability is the major driver for development of higher data speed technologies. GSM operators have two nonexclusive options for evolving their networks to 3G wide band multimedia operation: (1) they can use General Packet Radio Service (GPRS) and Enhanced Data rates for GSM Evolution (EDGE) [also known as 2.5G] in the existing radio spectrum, and in small amounts of new spectrum; or (2) they can use WCDMA/UMTS in the new 2 GHz bands [12,15,16]. Both approaches offer a high degree of investment flexibility because roll-out can proceed in line with market demand and there is extensive reuse of existing network equipment and radio sites. The first step to introduce high-speed circuit-switched data service in GSM is by using High Speed Circuit Switched Data (HSCSD). HSCSD is a feature that enables the co-allocation of multiple full rate traffic channels (TCH/F) of GSM into an HSCSD configuration. The aim of HSCSD is to provide a mixture of

1.4

Road Map for Higher Data Rate Capability in 3G

9

services with different user data rates using a single physical layer structure. The available capacity of an HSCSD configuration is several times the capacity of a TCH/F, leading to a significant enhancement in data transfer capability. Ushering faster data rates into the mainstream is the new speed of 14.4 kbps per time slot and HSCSD protocols that approach wire-line access rates of up to 57.6 kbps by using multiple 14.4 kbps time slots. The increase from the current baseline 9.6 kbps to 14.4 kbps is due to a nominal reduction in the error-correction overhead of the GSM radio link protocol, allowing the use of a higher data rate. The next phase in the high speed road map is the evolution of current short message service (SMS), such as smart messaging and unstructured supplementary service data, toward the new GPRS, a packet data service using TCP/IP and X.25 to offer speeds up to 115.2 kbps. GPRS has been standardized to optimally support a wide range of applications ranging from very frequent transmissions of medium to large data volume. Services of GPRS have been developed to reduce connection set-up time and allow an optimum usage of radio resources. GPRS provides a packet data service for GSM where time slots on the air interface can be assigned to GPRS over which packet data from several mobile stations can be multiplexed. A similar evolution strategy, also adopting GPRS, has been developed for DAMPS (IS-136). For operators planning to offer wide band multimedia services, the move to GPRS packet-based data bearer service is significant; it is a relatively small step compared to building a totally new 3G network. Use of the GPRS network architecture for IS-136 packet data service enables data subscription roaming with GSM networks around the globe that support GPRS and its evolution. The IS-136 packet data service standard is known as GPRS-136. GPRS-136 provides the same capabilities as GSM GPRS. The user can access either X.25 or IP-based data networks. GPRS provides a core network platform for current GSM operators not only to expand the wireless data market in preparation for the introduction of 3G services, but also a platform on which to build UMTS frequencies should they acquire them. GPRS enhances GSM data services significantly by providing end-to-end packet switched data connections. This is particularly efficient in Internet/intranet traffic, where short bursts of intense data communications actively are interspersed with relatively long periods of inactivity. Since there is no real end-to-end connection to be established, setting up a GPRS call is almost instantaneous and users can be continuously on-line. Users have the additional benefits of paying for the actual data transmitted, rather than for connection time. Because GPRS does not require any dedicated end-to-end connection, it only uses network resources and bandwidth when data is actually being transmitted. This means that a given amount of radio bandwidth can be shared efficiently between many users simultaneously.

10

1

An Overview of Wireless Systems

The significance of EDGE (also referred to as 2.5G system) for today’s GSM operators is that it increases data rates up to 384 kbps and potentially even higher in good quality radio environments that are using current GSM spectrum and carrier structures more efficiently. EDGE will both complement and be an alternative to new WCDMA coverage. EDGE will also have the effect of unifying the GSM, DAMPS, and WCDMA services through the use of dual-mode terminals. GSM operators who win licenses in new 2 GHz bands will be able to introduce UMTS wideband coverage in areas where early demand is likely to be greatest. Dual-mode EDGE/ UMTS mobile terminals will allow full roaming and handoff from one system to the other, with mapping of services between the two systems. EDGE will contribute to the commercial success of the 3G system in the vital early phases by ensuring that UMTS subscribers will be able to enjoy roaming and interworking globally. While GPRS and EDGE require new functionality in the GSM network with new types of connections to external packet data networks, they are essentially extensions of GSM. Moving to a GSM/UMTS core network will likewise be a further extension of this network. EDGE provides GSM operators — whether or not they get a new 3G license — with a commercially attractive solution for developing the market for wide band multimedia services. Using familiar interfaces such as the Internet, volume-based charging and a progressive increase in available user data rates will remove some of the barriers to large-scale take-up of wireless data services. The move to 3G services will be a staged evolution from today’s GSM data services using GPRS and EDGE. Table 1.1 provides a comparison of GSM data services. Table 1.1 Comparison of GSM data services.

Service type

Data unit

Max. sustained user data rate

Technology

Resources used

Short Message Service (SMS)

Single 140 octet packet

9 bps

simplex circuit

SDCCH or SACCH

CircuitSwitched Data

30 octet frames

9.6 kbps

duplex circuits

TCH

HSCSD

192 octet frames

115 kbps

duplex circuits

1-8 TCH

GPRS

1600 octet frames

115 kbps

virtual circuit packet switching

PDCH (1-8 TCH)

EDGE (2.5G)

variable

384 kbps

virtual circuit/ packet switching

1-8 TCH

Note: SDCCH: Stand-alone Dedicated Control Channel; SACCH: Slow Associated Control Channel; TCH: Traffic Channel; PDCH: Packet Data Channel (all refer to GSM logical channels)

1.4

Road Map for Higher Data Rate Capability in 3G

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The use of CDMA technology began in the United States with the development of the IS-95 standard in 1990. The IS-95 standard has evolved since to provide better voice services and applications to other frequency bands (IS-95A), and to provide higher data rates (up to 115.2 kbps) for data services (IS-95B). To further improve the voice service capability and provide even higher data rates for packet and circuit switched data services, the industry developed the cdma2000 standard in 2000. As the concept of wireless Internet gradually turns into reality, the need for an efficient high-speed data system arises. A CDMA high data rate (HDR) system was developed by Qualcomm. The CDMA-HDR (now called 3G 1X EV-DO, [3G 1X Enhanced Version Data Only]) system design improves the system throughput by using fast channel estimation feedback, dual receiver antenna diversity, and scheduling algorithms that take advantage of multi-user diversity. 3G 1X EV-DO has significant improvements in the downlink structure of cdma2000 including adaptive modulation of up to 8-PSK and 16-quadrature amplitude modulation (QAM), automatic repeat request (ARQ) algorithms and turbo coding. With these enhancements, 3G 1X EV-DO can transmit data in burst rates as high as 2.4 Mbps with 0.5 to 1 Mbps realistic downlink rates for individual users. The uplink design is similar to that in cdma2000. Recently, the 3G 1X EV-Data and Voice (DV) standard was finalized by the TIA and commercial equipment is currently being developed for its deployment. 3G 1X EV-DV can transmit both voice and data traffic on the same carrier with peak data throughput for the downlink being confirmed at 3.09 Mbps. As an alternative, Time Division-Synchronous CDMA (TD-SCDMA) has been developed by Siemens and the Chinese government. TD-SCDMA uses adaptive modulation of up to quadrature phase shift keying (QPSK) and 8-PSK, as well as turbo coding to obtain downlink data throughput of up to 2 Mbps. TD-SCDMA uses a 1.6 MHz time-division duplex (TDD) carrier whereas cdma2000 uses a 2  1.25 MHz frequency-division duplex (FDD) carrier (2.5 MHz total). TDD allows TD-SCDMA to use the least amount of spectrum of any 3G technologies. Table 1.2 lists the maximum data rates per user that can be achieved by various systems under ideal conditions. When the number of users increases, and if all the users share the same carrier, the data rate per user will decrease. One of the objectives of 3G systems is to provide access “anywhere, any time.” However, cellular networks can only cover a limited area due to high infrastructure costs. For this reason, satellite systems will form an integral part of the 3G networks. Satellite will provide extended wireless coverage to remote areas and to aerona