Title Details

David D. Coleman, CWNE #4, CWST, CWNA, CWSP, CWNT, is the Global Training Manager for Aerohive Networks. He is the author of numerous books and white papers about Wi-Fi technology and also holds Microsoft and Cisco certifications. He is also a member of the CWNE Roundtable, made up of the most respected wireless professionals in the world. David A. Westcott, CWNE #7, CWST, CWNA, CWSP, CWNT, is an independent consultant and technical trainer with over 23 years of experience. David has been a certified trainer for over 15 years. He is also a member of the CWNE Roundtable. Both coauthored the two previous editions of the CWNA Study Guide.

About the CWNP Program

CWNP is the industry standard for vendor-neutral, enterprise WLAN certifications. The focus is to educate IT professionals in the technology behind all enterprise WLAN products and to enable these professionals to manage wireless LAN enterprise infrastructures, regardless of the vendor solution utilized. CWNP is a privately held corporation based in Atlanta, Georgia. For more information, visit www.cwnp.com.

Introduction xxix

Assessment Test xlviii

Chapter 1 Overview of Wireless Standards, Organizations, and Fundamentals 1

History of WLAN 2

Standards Organizations 4

Federal Communications Commission 5

International Telecommunication Union Radiocommunication Sector 6

Institute of Electrical and Electronics Engineers 7

Internet Engineering Task Force 8

Wi-Fi Alliance 10

International Organization for Standardization 14

Core, Distribution, and Access 15

Communications Fundamentals 17

Understanding Carrier Signals 17

Understanding Keying Methods 20

Summary 24

Exam Essentials 25

Review Questions 26

Chapter 2 Radio Frequency Fundamentals 31

What Is a Radio Frequency Signal? 33

Radio Frequency Characteristics 34

Wavelength 34

Frequency 38

Amplitude 40

Phase 41

Radio Frequency Behaviors 42

Wave Propagation 42

Absorption 43

Reflection 44

Scattering 46

Refraction 46

Diffraction 47

Loss (Attenuation) 49

Free Space Path Loss 51

Multipath 53

Gain (Amplification) 57

Summary 58

Exam Essentials 58

Review Questions 59

Chapter 3 Radio Frequency Components, Measurements, and Mathematics 63

RF Components 65

Transmitter 65

Antenna 66

Receiver 67

Intentional Radiator (IR) 67

Equivalent Isotropically Radiated Power 67

Units of Power and Comparison 69

Watt 70

Milliwatt (mW) 70

Decibel (dB) 71

dBi 73

dBd 74

dBm 74

Inverse Square Law 76

RF Mathematics 77

Rule of 10s and 3s 77

Noise Floor 87

Signal-to-Noise Ratio (SNR) 87

Received Signal Strength Indicator 88

Link Budget 92

Fade Margin/System Operating Margin 95

Summary 97

Exam Essentials 98

Review Questions 99

Chapter 4 Radio Frequency Signal and Antenna Concepts 103

Azimuth and Elevation Charts

(Antenna Radiation Envelopes) 105

Interpreting Polar Charts 108

Beamwidth 110

Antenna Types 113

Omnidirectional Antennas 113

Semidirectional Antennas 116

Highly Directional Antennas 118

Sector Antennas 120

Antenna Arrays 122

Visual Line of Sight 124

RF Line of Sight 124

Fresnel Zone 125

Earth Bulge 129

Antenna Polarization 130

Antenna Diversity 131

Multiple-Input Multiple-Output 132

MIMO Antennas 132

Indoor MIMO Antennas 133

Outdoor MIMO Antennas 133

Antenna Connection and Installation 134

Voltage Standing Wave Ratio 134

Signal Loss 135

Antenna Mounting 136

Antenna Accessories 141

Cables 141

Connectors 142

Splitters 143

Amplifiers 143

Attenuators 144

Lightning Arrestors 145

Grounding Rods and Wires 147

Summary 148

Exam Essentials 148

Review Questions 149

Chapter 5 IEEE 802.11 Standards 153

Original IEEE 802.11 Standard 156

IEEE 802.11-2007 Ratified Amendments 158

802.11b 159

802.11a 160

802.11g 161

802.11d 164

802.11h 165

802.11i 167

802.11j 168

802.11e 168

Post 2007 Ratified Amendments 169

802.11r-2008 170

802.11k-2008 170

802.11y-2008 171

802.11w-2009 172

802.11n-2009 173

802.11z-2010 173

802.11u-2011 173

802.11v-2011 174

802.11s-2011 174

IEEE 802.11 Draft Amendments 175

802.11p 176

802.11aa 176

802.11ac 177

802.11ad 177

802.11ae 178

802.11af 178

802.11ah 178

Defunct Amendments 178

802.11F 178

802.11T 181

802.11m Task Group 182

Summary 182

Exam Essentials 183

Review Questions 184

Chapter 6 Wireless Networks and Spread Spectrum Technologies 189

Industrial, Scientific, and Medical Bands 191

900 MHz ISM Band 191

2.4 GHz ISM Band 192

5.8 GHz ISM Band 192

Unlicensed National Information Infrastructure Bands 193

UNII-1 (Lower Band) 193

UNII-2 (Middle Band) 194

UNII-2 Extended 194

UNII-3 (Upper Band) 195

3.6 GHz Band 196

4.9 GHz Band 196

Future Wi-Fi Frequencies 196

60 GHz 196

White-Fi 197

Narrowband and Spread Spectrum 197

Multipath Interference 199

Frequency Hopping Spread Spectrum 200

Hopping Sequence 200

Dwell Time 201

Hop Time 201

Modulation 202

Direct Sequence Spread Spectrum 202

DSSS Data Encoding 203

Modulation 204

Packet Binary Convolutional Code 204

Orthogonal Frequency Division Multiplexing 205

Convolutional Coding 206

Modulation 206

2.4 GHz Channels 207

5 GHz Channels 211

Adjacent, Nonadjacent, and Overlapping Channels 213

Throughput vs. Bandwidth 214

Communication Resilience 215

Summary 216

Exam Essentials 217

Review Questions 217

Chapter 7 Wireless LAN Topologies 221

Wireless Networking Topologies 222

Wireless Wide Area Network (WWAN) 223

Wireless Metropolitan Area

Network (WMAN) 223

Wireless Personal Area Network 224

Wireless Local Area Network 224

802.11 Topologies 225

Access Point 226

Client Station 227

Integration Service 227

Distribution System 227

Wireless Distribution System 228

Service Set Identifier 231

Basic Service Set 232

Basic Service Set Identifier 233

Basic Service Area 233

Extended Service Set 234

Independent Basic Service Set 237

Mesh Basic Service Set 238

802.11 Configuration Modes 239

Access Point Modes 239

Client Station Modes 240

Summary 241

Exam Essentials 241

Review Questions 243

Chapter 8 802.11 Medium Access 247

CSMA/CA vs. CSMA/CD 248

Collision Detection 249

Distributed Coordination Function 250

Interframe Space (IFS) 250

Duration/ID Field 251

Carrier Sense 252

Random Back-off Timer 254

Point Coordination Function 255

Hybrid Coordination Function 255

Enhanced Distributed Channel Access 256

HCF Controlled Channel Access 257

Block Acknowledgment 257

Wi-Fi Multimedia 258

Airtime Fairness 260

Summary 261

Exam Essentials 262

Review Questions 263

Chapter 9 802.11 MAC Architecture 267

Packets, Frames, and Bits 269

Data-Link Layer 270

MAC Service Data Unit 270

MAC Protocol Data Unit 270

Physical Layer 271

PLCP Service Data Unit 271

PLCP Protocol Data Unit 271

802.11 and 802.3 Interoperability 272

Three 802.11 Frame Types 273

Management Frames 273

Control Frames 274

Data Frames 275

Beacon Management Frame 276

Passive Scanning 277

Active Scanning 278

Authentication 280

Open System Authentication 280

Shared Key Authentication 281

Association 282

Authentication and Association States 282

Basic and Supported Rates 283

Roaming 284

Reassociation 284

Disassociation 286

Deauthentication 287

ACK Frame 287

Fragmentation 288

Protection Mechanism 290

RTS/CTS 293

CTS-to-Self 294

Data Frames 295

Power Management 296

Active Mode 297

Power Save Mode 297

Traffic Indication Map 297

Delivery Traffic Indication Message 298

Announcement Traffic Indication Message 299

WMM Power Save and U-APSD 300

802.11n Power Management 302

Band Steering 302

Summary 303

Exam Essentials 304

Review Questions 306

Chapter 10 WLAN Architecture 311

Wireless LAN Client Devices 312

Radio Card Formats 313

Radio Card Chipsets 317

Client Utilities 318

Management, Control, and Data Planes 322

Management Plane 322

Control Plane 323

Data Plane 323

WLAN Architecture 323

Autonomous WLAN Architecture 324

Wireless Network Management System 325

Centralized WLAN Architecture 327

Distributed WLAN Architecture 336

Unified WLAN Architecture 337

Specialty WLAN Infrastructure 337

Wireless Workgroup Bridge 338

Wireless LAN Bridges 339

Home Wi-Fi Router 341

Wireless LAN Mesh Access Points 342

WLAN Array 343

Virtual AP System 344

Real-Time Location Systems 344

VoWiFi 346

Summary 348

Exam Essentials 348

Review Questions 350

Chapter 11 WLAN Deployment and Vertical Markets 355

Deployment Considerations for Commonly Supported WLAN Applications and Devices 356

Data 356

Voice 357

Video 357

Real-Time Location Services 358

Mobile Devices 359

Corporate Data Access and End-User Mobility 360

Network Extension to Remote Areas 360

Bridging: Building-to-Building Connectivity 361

Wireless ISP: Last-Mile Data Delivery 362

Small Office/Home Office 362

Mobile Office Networking 363

Educational/Classroom Use 363

Industrial: Warehousing

and Manufacturing 364

Healthcare: Hospitals and Offices 364

Municipal Networks 366

Hotspots: Public Network Access 366

Transportation Networks 368

Law Enforcement Networks 368

First-Responder Networks 369

Fixed Mobile Convergence 370

WLAN and Health 371

WLAN Vendors 371

Summary 373

Exam Essentials 373

Review Questions 375

Chapter 12 WLAN Troubleshooting 379

Layer 2 Retransmissions 380

RF Interference 382

Multipath 385

Adjacent Channel Interference 387

Low SNR 390

Mismatched Power Settings 391

Near/Far 393

Hidden Node 394

802.11 Coverage Considerations 398

Dynamic Rate Switching 398

Roaming 401

Layer 3 Roaming 405

Co-channel Interference 407

Channel Reuse/Multiple Channel Architecture 409

Single-Channel Architecture 414

Capacity vs. Coverage 416

Oversized Coverage Cells 418

Physical Environment 418

Voice vs. Data 418

Performance 420

Weather 421

Summary 422

Exam Essentials 422

Review Questions 424

Chapter 13 802.11 Network Security Architecture 429

802.11 Security Basics 431

Data Privacy 432

Authentication, Authorization, and Accounting 433

Segmentation 434

Monitoring and Policy 434

Legacy 802.11 Security 434

Legacy Authentication 435

Static WEP Encryption 436

MAC Filters 438

SSID Cloaking 439

Robust Security 440

Robust Security Network (RSN) 441

Authentication and Authorization 442

PSK Authentication 442

Proprietary PSK Authentication 443

802.1X/EAP Framework 445

EAP Types 448

Dynamic Encryption-Key Generation 448

4-Way Handshake 450

WPA/WPA2-Personal 451

TKIP Encryption 451

CCMP Encryption 452

Traffic Segmentation 454

VLANs 454

RBAC 454

Infrastructure Security 456

Physical Security 456

Interface Security 456

VPN Wireless Security 457

Layer 3 VPNs 457

SSL VPN 458

VPN Deployment 458

Guest WLAN Security 459

Captive Portal 460

Summary 462

Exam Essentials 462

Review Questions 464

Chapter 14 Wireless Attacks, Intrusion Monitoring, and Policy 469

Wireless Attacks 470

Rogue Wireless Devices 471

Peer-to-Peer Attacks 474

Eavesdropping 475

Encryption Cracking 478

Authentication Attacks 478

MAC Spoofing 480

Management Interface Exploits 481

Wireless Hijacking 482

Denial of Service (DoS) 483

Vendor-Specific Attacks 485

Social Engineering 485

Intrusion Monitoring 486

Wireless Intrusion Detection System 486

Wireless Intrusion Prevention System (WIPS) 489

Mobile WIDS 491

Spectrum Analyzer 492

Wireless Security Policy 493

General Security Policy 494

Functional Security Policy 494

Legislative Compliance 495

802.11 Wireless Policy Recommendations 496

Summary 497

Exam Essentials 497

Review Questions 498

Contents xxi

Chapter 15 Radio Frequency Site Survey Fundamentals 503

WLAN Site Survey Interview 504

Customer Briefing 504

Business Requirements 505

Capacity and Coverage Requirements 506

Existing Wireless Network 509

Infrastructure Connectivity 510

Security Expectations 512

Guest Access 512

Documents and Reports 513

Forms and Customer Documentation 513

Deliverables 515

Additional Reports 516

Vertical Market Considerations 517

Outdoor Surveys 517

Aesthetics 519

Government 519

Education 520

Healthcare 520

Hotspots 521

Retail 521

Warehouses 521

Manufacturing 522

Multitenant Buildings 522

Summary 523

Exam Essentials 523

Review Questions 524

Chapter 16 Site Survey Systems and Devices 529

Site Survey Defined 530

Protocol and Spectrum Analysis 531

Spectrum Analysis 532

Coverage Analysis 536

AP Placement and Configuration 541

Application Analysis 543

Site Survey Tools 544

Indoor Site Survey Tools 544

Outdoor Site Survey Tools 546

Coverage Analysis 549

Manual 549

Predictive 551

Self-Organizing Wireless LANs 552

Summary 553

Exam Essentials 554

Review Questions 555

Chapter 17 Power over Ethernet (PoE) 561

History of PoE 562

Nonstandard PoE 563

IEEE 802.3af 563

IEEE Std. 802.3-2005, Clause 33 563

IEEE 802.3at-2009 563

An Overview of PoE Devices 564

Powered Device 564

Power-Sourcing Equipment 566

Endpoint PSE 567

Midspan PSE 570

Power-Sourcing Equipment Pin Assignments 573

Planning and Deploying PoE 574

Power Planning 574

Redundancy 575

802.11n and PoE 577

Summary 578

Exam Essentials 578

Review Questions 579

Chapter 18 High Throughput (HT) and 802.11n 583

802.11n-2009 Amendment 585

Wi-Fi Alliance Certification 586

MIMO 588

Radio Chains 589

Spatial Multiplexing (SM) 590

MIMO Diversity 591

Space-Time Block Coding (STBC) 592

Cyclic Shift Diversity (CSD) 593

Transmit Beamforming (TxBF) 593

HT Channels 596

20 MHz Non-HT and HT Channels 596

40 MHz Channels 597

Forty MHz Intolerant 600

Guard Interval (GI) 600

Modulation and Coding Scheme (MCS) 601

HT PHY 604

Non-HT Legacy 605

HT Mixed 606

HT Greenfield 606

HT MAC 606

A-MSDU 607

A-MPDU 608

Block Acknowledgment 609

Reduced Interframe Space 609

HT Power Management 610

HT Operation 611

20/40 Channel Operation 611

HT Protection Modes (0–3) 611

RTS/CTS and CTS-to-Self 612

Summary 613

Exam Essentials 614

Review Questions 615

Appendix A Answers to Review Questions 619

Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals 620

Chapter 2: Radio Frequency Fundamentals 622

Chapter 3: Radio Frequency Components, Measurements, and Mathematics 623

Chapter 4: Radio Frequency Signal and Antenna Concepts 626

Chapter 5: IEEE 802.11 Standards 627

Chapter 6: Wireless Networks and Spread Spectrum Technologies 629

Chapter 7: Wireless LAN Topologies 631

Chapter 8: 802.11 Medium Access 633

Chapter 9: 802.11 MAC Architecture 635

Chapter 10: WLAN Architecture 637

Chapter 11: WLAN Deployment and Vertical Markets 639

Chapter 12: WLAN Troubleshooting 641

Chapter 13: 802.11 Network Security Architecture 644

Chapter 14: Wireless Attacks, Intrusion Monitoring, and Policy 646

Chapter 15: Radio Frequency Site Survey Fundamentals 649

Chapter 16: Site Survey Systems and Devices 651

Chapter 17: Power over Ethernet (PoE) 653

Chapter 18: High Throughput (HT)

and 802.11n 655

Appendix B Abbreviations, Acronyms, and Regulations 659

Certifications 660

Organizations and Regulations 660

Measurements 661

Technical Terms 662

Power Regulations 672

2.4 GHz ISM Point-to-Multipoint (PtMP) Communications 672

5 GHz UNII Point-to-Multipoint (PtMP) Communications 672

2.4 GHz ISM Point-to-Point (PtP) Communications 673

5 GHz UNII Point-to-Point (PtP) Communications 674

Appendix C About the Additional Study Tools 675

Additional Study Tools 676

Sybex Test Engine 676

Electronic Flashcards 676

PDF of Glossary of Terms 676

Adobe Reader 676

System Requirements 677

Using the Study Tools 677

Troubleshooting 677

Customer Care 678

Index 679