Fundamentals of WiMAX: Understanding Broadband Wireless Networking

by Jeffrey Andrews, Arunabha Ghosh, Rias Muhamed

Overview

The Definitive Guide to WiMAX Technology

WiMAX is the most promising new technology for broadband wireless access to IP services. It can serve an extraordinary range of applications and environments: data, voice, and multimedia; fixed and mobile; licensed and unlicensed. However, until now, wireless professionals have had little reliable information to guide them. Fundamentals of WiMAX is the first comprehensive guide to WiMAX—its technical foundations, features, and performance.

 

Three leading wireless experts systematically cut through the hype surrounding WiMAX and illuminate the realities. They combine complete information for wireless professionals and basic, accessible knowledge for non-experts. Professionals will especially appreciate their detailed discussion of the performance of WiMAX based on comprehensive link- and system-level simulations.

 

Whether you're a wireless engineer, network architect, manager, or system designer, this book delivers essential information for succeeding with WiMAX—from planning through deployment.

Topics include

• Applications, history, spectrum options, technical and business challenges, and competitive technologies of WiMAX

• 802.16 standards: physical and MAC layers, channel access, scheduling services, mobility, advanced antenna features, hybrid-ARQ, and more

• Broadband wireless channels: pathloss, shadowing, cellular systems, sectoring, and fading—including modeling and mitigation

• OFDM: from basic multicarrier concepts to synchronization, PAR reduction, and clipping

• MIMO: Multiple antennas, spatial diversity, beamforming, and a cutting-edge treatment of the use of MIMO in WiMAX

• OFDMA: multiple access, multiuser diversity, adaptive modulation, and resource allocation

• Networking and services aspects: architecture and protocols for IP QoS, session management, ecurity, and mobility management

• Predicting performance using link-level and system-level simulations

• WiMAX network architecture: design principles, reference models, authentication, QoS, and mobility management

Product Details

ISBN-13:	9780132712828
Publisher:	Pearson Education
Publication date:	02/27/2007
Series:	Communications Engineering & Emerging Technology Series from Ted Rappaport
Sold by:	Barnes & Noble
Format:	eBook
Pages:	432
File size:	10 MB
Age Range:	18 Years

About the Author

Jeffrey G. Andrews is an assistant professor at The University of Texas at Austin. He has developed CDMA systems for Qualcomm and consulted with many organizations including the WiMAX Forum, Microsoft, and NASA. He is a recipient of the NSF CAREER Award and holds a Ph.D. from Stanford University.

Arunabha Ghosh, a principal member of technical staff at AT&T Labs, specializes in wireless communication theory and signal processing and has been involved in standardization efforts in the WiMAX Forum. He holds a Ph.D. from the University of Illinois at Urbana-Champaign.

Rias Muhamed is a lead member of technical staff at AT&T Labs. He has led several research and technology assessment projects in fixed wireless broadband at AT&T Labs. He is a senior member of the IEEE and holds an M.S. from Virginia Tech.

Read an Excerpt

Fundamentals of WiMAX was consciously written to appeal to a broad audience, and to be of value to anyone who is interested in the IEEE 802.16e standards or wireless broadband networks more generally. The book contains cutting-edge tutorials on the technical and theoretical underpinnings to WiMAX that are not available anywhere else, while also providing high-level overviews that will be informative to the casual reader. The entire book is written with a tutorial approach that should make most of the book accessible and useful to readers who do not wish to bother with equations and technical details, but the details are there for those who want a rigorous understanding. In short, we expect this book to be of great use to practicing engineers, managers and executives, graduate students who want to learn about WiMAX, undergraduates who want to learn about wireless communications, attorneys involved with regulations and patents pertaining to WiMAX, and members of the financial community who want to understand exactly what WiMAX promises. Organization of the Book

The book is organized into three parts with a total of twelve chapters. Part I provides an introduction to broadband wireless and WiMAX. Part II presents a collection of rigorous tutorials covering the technical and theoretical foundations upon which WiMAX is built. In Part III we present a more detailed exposition of the WiMAX standard, along with a quantitative analysis of its performance.

In Part I, Chapter 1 provides the background information necessary for understanding WiMAX. We provide a brief history of broadband wireless, enumerate its applications, discuss the market drivers and competitivelandscape, and present a discussion of the business and technical challenges to building broadband wireless networks. Chapter 2 provides an overview of WiMAX and serves as a summary of the rest of the book. This chapter is written as a standalone tutorial on WiMAX and should be accessible to anyone interested in the technology.

We begin Part II of the book with Chapter 3, where the immense challenge presented by a time-varying broadband wireless channel is explained. We quantify the principal effects in broadband wireless channels, present practical statistical models, and provide an overview of diversity countermeasures to overcome the challenges. Chapter 4 is a tutorial on OFDM, where the elegance of multicarrier modulation and the theory of how it works are explained. The chapter emphasizes a practical understanding of OFDM system design and discusses implementation issues for WiMAX systems such as the peak-to-average ratio. Chapter 5 presents a rigorous tutorial on multiple antenna techniques covering a broad gamut of techniques from simple receiver diversity to advanced beamforming and spatial multiplexing. The practical considerations in the application of these techniques to WiMAX are also discussed. Chapter 6 focuses on OFDMA, another key-ingredient technology responsible for the superior performance of WiMAX. The chapter explains how OFDMA can be used to enhance capacity through the exploitation of multiuser diversity and adaptive modulation, and also provides a survey of different scheduling algorithms. Chapter 7 covers end-to-end aspects of broadband wireless networking such as QoS, session management, security, and mobility management. WiMAX being an IP-based network, this chapter highlights some of the relevant IP protocols used to build an end-to-end broadband wireless service. Chapters 3 though 7 are more likely to be of interest to practicing engineers, graduate students, and others wishing to understand the science behind the WiMAX standard.

In Part III of the book, Chapters 8 and 9 describe the details of the physical and media access control layers of the WiMAX standard and can be viewed as a distilled summary of the far more lengthy IEEE 802.16e-2005 and IEEE 802.16-2004 specifications. Sufficient details of these layers of WiMAX are provided in these chapters to enable the reader to gain a solid understanding of the salient features and capabilities of WiMAX and build computer simulation models for performance analysis. Chapter 10 describes the networking aspects of WiMAX, and can be thought of as a condensed summary of the end-to-end network systems architecture developed by the WiMAX Forum. Chapters 11 and 12 provide an extensive characterization of the expected performance of WiMAX based on the research and simulation-based modeling work of the authors. Chapter 11 focuses on the link-level performance aspects, while Chapter 12 presents system-level performance results for multicellular deployment of WiMAX.

Table of Contents

Foreword xix Preface xxi Acknowledgments xxiii About the Authors xxvii Part I Overview of WiMAX 1 Chapter 1 Introduction to Broadband Wireless 3

1.1 Evolution of Broadband Wireless 5

1.2 Fixed Broadband Wireless: Market Drivers and Applications 10

1.3 Mobile Broadband Wireless: Market Drivers and Applications 12

1.4 WiMAX and Other Broadband Wireless Technologies 13

1.5 Spectrum Options for Broadband Wireless 17

1.6 Business Challenges for Broadband Wireless and WiMAX 21

1.7 Technical Challenges for Broadband Wireless 23

1.8 Summary and Conclusions 32

1.9 Bibliography 32

Chapter 2 Overview of WiMAX 33

2.1 Background on IEEE 802.16 and WiMAX 33

2.2 Salient Features of WiMAX 37

2.3 WiMAX Physical Layer 39

2.4 MAC-Layer Overview 47

2.5 Advanced Features for Performance Enhancements 55

2.6 Reference Network Architecture 57

2.7 Performance Characterization 59

2.8 Summary and Conclusions 61

2.9 Bibliography 63

Part II Technical Foundations of WiMAX 65 Chapter 3 The Challenge of Broadband Wireless Channels 67

3.1 Communication System Building Blocks 68

3.2 The Broadband Wireless Channel: Pathloss and Shadowing 69

3.3 Cellular Systems 77

3.4 The Broadband Wireless Channel: Fading 84

3.5 Modeling Broadband Fading Channels 91

3.6 Mitigation of Fading 104

3.7 Summary and Conclusions 110

3.8 Bibliography 110

Chapter 4 Orthogonal Frequency Division Multiplexing 113

4.1 Multicarrier Modulation 114

4.2 OFDM Basics 117

4.3 An Example: OFDM in WiMAX 123

4.4 Timing and Frequency Synchronization 124

4.5 The Peak-to-Average Ratio 131

4.6 OFDM's Computational Complexity Advantage 142

4.7 Simulating OFDM Systems 144

4.8 Summary and Conclusions 145

4.9 Bibliography 145

Chapter 5 Multiple-Antenna Techniques 149

5.1 The Benefits of Spatial Diversity 150

5.2 Receive Diversity 154

5.3 Transmit Diversity 157

5.4 Beamforming 169

5.5 Spatial Multiplexing 174

5.6 Shortcomings of Classical MIMO Theory 181

5.7 Channel Estimation for MIMO-OFDM 184

5.8 Channel Feedback 189

5.9 Advanced Techniques for MIMO 190

Chapter 6 Orthogonal Frequency Division Multiple Access 199

6.1 Multiple-Access Strategies for OFDM 200

6.2 Multiuser Diversity and Adaptive Modulation 204

6.3 Resource-Allocation Techniques for OFDMA 209

6.4 OFDMA in WiMAX: Protocols and Challenges 216

6.5 Summary and Conclusions 219

6.6 Bibliography 220

Chapter 7 Networking and Services Aspects of Broadband Wireless 223

7.1 Quality of Service 224

7.2 Multimedia Session Management 233

7.3 Security 241

7.4 Mobility Management 249

7.5 IP for Wireless: Issues and Potential Solutions 260

7.6 Summary and Conclusions 265

7.7 Bibliography 266

Part III Understanding WiMAX and Its Performance 269 Chapter 8 PHY Layer of WiMAX 271

8.1 Channel Coding 272

8.2 Hybrid-ARQ 278

8.3 Interleaving 279

8.4 Symbol Mapping 280

8.5 OFDM Symbol Structure 280

8.6 Subchannel and Subcarrier Permutations 282

8.7 Slot and Frame Structure 290

8.8 Transmit Diversity and MIMO 292

8.9 Closed-Loop MIMO 296

8.10 Ranging 300

8.11 Power Control 302

8.12 Channel-Quality Measurements 303

8.13 Summary and Conclusions 304

8.14 Bibliography 304

Chapter 9 MAC Layer of WiMAX 307

9.1 Convergence Sublayer 309

9.2 MAC PDU Construction and Transmission 312

9.3 Bandwidth Request and Allocation 316

9.4 Quality of Service 317

9.5 Network Entry and Initialization 319

9.6 Power-Saving Operations 324

9.7 Mobility Management 327

9.8 Summary and Conclusions 332

9.9 Bibliography 333

Chapter 10 WiMAX Network Architecture 335

10.1 General Design Principles of the Architecture 336

10.2 Network Reference Model 337

10.3 Protocol Layering Across a WiMAX Network 341

10.4 Network Discovery and Selection 344

10.5 IP Address Assignment 344

10.6 Authentication and Security Architecture 345

10.7 Quality-of-Service Architecture 349

10.8 Mobility Management 352

10.9 Radio Resource Management 359

10.10 Paging and Idle-Mode Operation 360

10.11 Summary and Conclusions 362

10.12 Bibliography 362

Chapter 11 Link-Level Performance of WiMAX 365

11.1 Methodology for Link-Level Simulation 366

11.2 AWGN Channel Performance of WiMAX 370

11.3 Fading Channel Performance of WiMAX 373

11.4 Benefits of Multiple-Antenna Techniques in WiMAX 387

11.5 Advanced Receiver Structures and Their Benefits for WiMAX 396

11.6 Summary and Conclusions 398

11.7 Bibliography 399

Chapter 12 System-Level Performance of WiMAX 401

12.1 Wireless Channel Modeling 402

12.2 Methodology for System-Level Simulation 404

12.3 System-Level Simulation Results 412

12.4 Summary and Conclusions 421

12.5 Appendix: Propagation Models 422

12.6 Bibliography 427

Acronyms Index