Wiley Publishing, Inc.
CWNA
®
Certified Wireless
Network Administrator
™
Study Guide
David D. Coleman
David A. Westcott
89526book.fm Page iii Tuesday, July 25, 2006 2:24 PM
89526book.fm Page ii Tuesday, July 25, 2006 2:24 PM
CWNA
®
Certified Wireless
Network Administrator
™
Study Guide
89526book.fm Page i Tuesday, July 25, 2006 2:24 PM
89526book.fm Page ii Tuesday, July 25, 2006 2:24 PM
Wiley Publishing, Inc.
CWNA
®
Certified Wireless
Network Administrator
™
Study Guide
David D. Coleman
David A. Westcott
89526book.fm Page iii Tuesday, July 25, 2006 2:24 PM
Acquisitions and Development Editor: Jeff Kellum
Technical Editor: Sam Coyl
Production Editor: Martine Dardignac
Copy Editor: Judy Flynn
Production Manager: Tim Tate
Vice President and Executive Group Publisher: Richard Swadley
Vice President and Executive Publisher: Joseph B. Wikert
Vice President and Publisher: Neil Edde
Permissions Editor: Shannon Walters
Media Development Specialist: Kate Jenkins
Book Designers: Judy Fung and Bill Gibson
Compositor: Laurie Stewart, Happenstance Type-O-Rama
Illustrator: Jeffrey Wilson, Happenstance Type-O-Rama
Proofreader: Nancy Riddiough
Indexer: Nancy Guenther
Cover Designer: Ryan Sneed
Copyright © 2006 by Wiley Publishing, Inc., Indianapolis, Indiana
Published simultaneously in Canada
ISBN-13: 978-0-471-78952-9
ISBN-10: 0-471-78952-6
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, recording, scanning or otherwise, except as permitted under Sections
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respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including
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mean that the author or the publisher endorses the information the organization or Website may provide or recom-
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TRADEMARKS: Wiley, the Wiley logo, and the Sybex logo are trademarks or registered trademarks of John
Wiley & Sons, Inc. and/or its affiliates, in the United States and other countries, and may not be used without writ-
ten permission. CWNA and Certified Wireless Network Administrator are trademarks or registered trademarks
of Planet3 Wireless, Inc. in the United States and other countries. All other trademarks are the property of their
respective owners. Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book.
10 9 8 7 6 5 4 3 2 1
89526book.fm Page iv Tuesday, July 25, 2006 2:24 PM
To Our Valued Readers:
Thank you for looking to Sybex for your CWNA exam prep needs. We at Sybex are proud
of our reputation for providing certification candidates with the practical knowledge and
skills needed to succeed in the highly competitive IT marketplace. Certification candidates
have come to rely on Sybex for accurate and accessible instruction on today’s crucial tech-
nologies and business skills.
Just as Planet3 is committed to establishing measurable standards for certifying IT wireless
administration professionals by means of the CWNA certification, Sybex is committed to
providing those individuals with the knowledge needed to meet those standards.
The authors and editors have worked hard to ensure that this edition of the
CWNA: Certi-
fied Wireless Network Administrator Study Guide
you hold in your hands is comprehensive,
in-depth, and pedagogically sound. We’re confident that this book will exceed the demand-
ing standards of the certification marketplace and help you, the CWNA certification candi-
date, succeed in your endeavors.
As always, your feedback is important to us. If you believe you’ve identified an error in the
book, please send a detailed e-mail to
. And if you have general com-
ments or suggestions, feel free to drop me a line directly at
. At Sybex
we’re continually striving to meet the needs of individuals preparing for certification exams.
Good luck in pursuit of your CWNA certification!
Neil Edde
Vice President & Publisher
Wiley Publishing, Inc.
89526book.fm Page v Tuesday, July 25, 2006 2:24 PM
We would like to dedicate this book to our parents, teachers, instructors, and
mentors, who have helped us throughout our lives. We hope that through this book
and through our teaching and mentoring we can help others achieve their goals.
89526book.fm Page vi Tuesday, July 25, 2006 2:24 PM
Acknowledgments
David Coleman would like to thank his children, Brantley and Carolina, for their patience and
understanding of their father throughout the writing of the book. I love you kids very much.
David Westcott would like to thank his wife, Gina, for her patience, understanding, and
support and for the hours she spent reading and editing the book.
Writing the CWNA study guide has been a nine-month adventure that neither of us fully
grasped from the start. We would like to thank all of the following individuals for their sup-
port and contributions during the entire process.
We must first thank Acquisitions and Developmental Editor Jeff Kellum of Sybex Publish-
ing for initially finding us and bringing us on to this project. Jeff is an extremely patient and
understanding editor who, despite our best efforts, needed to send us an occasional nasty e-mail
message. We would also like to thank Project Editor Martine Dardignac of Wiley. Martine
was an absolute pleasure to work with despite the fact that we drove her crazy. We would also
love to thank our copyeditor, Judy Flynn; our proofreader, Nancy Riddiough; the illustrators;
and our media development specialist, Shannon Walters.
We need to give a big shout out to our technical editor, Sam Coyle. Sam is a member of the
IEEE with many years of practical experience in wireless communications. His contributions to
the book were nothing short of invaluable. When Sam is not providing awesome technical edit-
ing, he is vice president of business development for Kandersteg\Netrepid (
www.netrepid.com
),
a wireless solutions provider.
We would also like to thank Devin Akin, Kevin Sandlin, Scott Turner, and Scott Williams
of the CWNP Program (
www.cwnp.com
). You gentlemen should be proud of the internation-
ally renowned wireless certification program that you have developed. It has been a pleasure
working with all of you the past four years.
Thanks to Proxim and to Ken Ruppel (
) for allowing us to include
the video “Beam Patterns and Polarization of Directional Antennas” on the CD-ROM, and
thanks to Andrew Potter for making himself available for our photography needs.
Special thanks goes to Andras Szilagyi, not only for creating the EMANIM software pro-
gram, but also for all the extra assistance he provided by working with us to create a custom-
ized version of the program for the CD-ROM.
We would also like to think the following individuals and companies for their contributions
to the book:
• Air Defense—Nico Darrow, Ralf Deltrap, and Bryan Harkins (
www.airdefense.net
)
• Air Magnet—Jonathan Bass and Chia Chee Kuan (
www.airmagnet.com
)
• AirWave (
www.airwave.com
)
• Andrew Potter Photography—Andrew Potter (
www.andrewpotterphotography.com
)
• Aruba Networks—Christopher Leach (
www.arubanetworks.com
)
• Cognio—William Flanagan and Margo Schlossberg (
www.cognio.com
)
• Cushcraft—Mark Miller (
www.cushcraft.com
)
• D-Link—(
www.dlink.com
)
• Ekahau—Jussi Kiviniemi (
www.ekahau.com
)
• Fortress Technologies—Andrea Shirley and Joe Tomasone (
www.fortresstech.com
)
89526book.fm Page vii Tuesday, July 25, 2006 2:24 PM
viii
Acknowledgments
• Helium Networks—Keith Borden, Ed Finn, and Walt Halasowski
(
www.heliumnetworks.com
)
• Juniper Networks—Curt Hooper, Paul Levesque, and Matt Sweet (
www.juniper.net
)
• NetStumbler—Marius Milner (
www.netstumbler.com
)
• Ortronics—Jeff Davis, Arlene Franchini, and Irene Bammer (
www.ortronics.com
)
• Proxim—Ken Day, Pamela Valentine, and Amit Malhotra (
www.proxim.com
)
• SpectraLink—Melissa Aguirre, Ray Baum, Wayne McAllister, Wylee Post, and
Robin Raulf-Sager (
www.spectralink.com
)
• Spectrotech—Mark Morgan (
www.spectrotech.com.au
)
• TamoSoft—Michael Berg (
www.tamosoft.com
)
• Times Microwave Systems—Joe Lanoue (
www.timesmicrowave.com
)
• Wi-Fi Alliance—Kelly Davis-Felner (
www.wifi.org
)
• Wildpackets—Stephanie Temple (
www.wildpackets.com
)
89526book.fm Page viii Tuesday, July 25, 2006 2:24 PM
Foreword
Wireless LANs seem to be everywhere these days. The technology is advancing so rapidly that
it seems almost impossible to stay abreast of all of the changes. The small office/home office
(SOHO) sector is adopting new WLAN technologies well before there are ratified amend-
ments or interoperability certifications in place for each technology. The small/medium busi-
ness (SMB) sector is slightly more cautious but often serves as a test bed for many leading-edge
technologies. The enterprise has adopted 802.11 technology slowly over the last five years,
and adoption has often been due to driving factors such as saving money, as with VoWiFi and
device tracking technologies, or being able to accomplish new business goals that could not be
achieved without wireless technology.
Wireless has recently become wildly popular in the enterprise, and vendors are frantically
releasing new products into the market. With a relentless stream of new technologies and
products comes an increased demand for education and certification. The CWNP Program is
dedicated strictly to staying abreast of all facets of 802.11 technology—with both standards
and products. The CWNA certification is the first step in the CWNP line of certifications and
is focused on administering an enterprise 802.11 WLAN. CWNA includes topics such as
802.11 standards, security, management, protocol analysis, QoS, site surveying, and radio fre-
quency. Additional certifications focus more intensely on security, protocol analysis, QoS, and
RF spectrum management.
David Coleman and David Westcott have worked as Certified Wireless Network Trainers
(CWNTs) for as long as the CWNT certification has been available, and each was quick to
pursue all CWNP certifications as they were released. Each has years of experience with a
breadth of WLAN technologies and leading-edge products, which is obvious to their stu-
dents and anyone working alongside them in the field. Having worked with each of these
gentlemen for years, I can confidently say there could be no finer pair of seasoned trainers
collaborating on a CWNA book. These WLAN veterans have devoted hundreds of hours to
pouring their experience into this book, and the reader is assured to acquire a plethora of
802.11 knowledge. Mr. Coleman and Mr. Westcott have participated in the shaping of the
CWNP Program as a whole since its earliest days and have each added tremendous value to
the CWNA certification specifically. I would like to thank each of these fine gentlemen for
their unwavering support of the CWNP Program, and I would like to congratulate them
on their diverse accomplishments as engineers, trainers, and now authors.
Devin Akin
Chief Technology Officer
The CWNP Program
89526book.fm Page ix Tuesday, July 25, 2006 2:24 PM
Contents at a Glance
Introduction xxiii
Assessment Test xxxviii
Chapter 1
Overview of Wireless Standards and Organizations 1
Chapter 2
Radio Frequency Fundamentals 23
Chapter 3
Radio Frequency Components, Measurements,
and Mathematics 55
Chapter 4
Radio Frequency Signal and Antenna Concepts 91
Chapter 5
IEEE 802.11 Standards 133
Chapter 6
Wireless Networks and Spread Spectrum Technologies 163
Chapter 7
Wireless LAN Topologies 193
Chapter 8
802.11 Medium Access 219
Chapter 9
802.11 MAC Architecture 251
Chapter 10
Wireless Devices 275
Chapter 11
Network Design, Implementation, and Management 309
Chapter 12
WLAN Troubleshooting 327
Chapter 13
802.11 Network Security Architecture 357
Chapter 14
Wireless Attacks, Intrusion Monitoring, and Policy 387
Chapter 15
Radio Frequency Site Survey Fundamentals 417
Chapter 16
Site Survey Systems and Devices 443
Glossary
477
Index 509
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Contents
Introduction xxiii
Assessment Test xxxviii
Chapter 1 Overview of Wireless Standards and Organizations 1
Identifying Standards Organizations 2
Federal Communications Commission (FCC) 3
International Telecommunication Union
Radiocommunication Sector (ITU-R) 4
Institute of Electrical and Electronics Engineers (IEEE) 5
Wi-Fi Alliance 6
International Organization for Standardization 7
Communications Fundamentals 8
Understanding Carrier Signals 8
Understanding Keying Methods 11
Summary 14
Exam Essentials 15
Key Terms 15
Review Questions 16
Answers to Review Questions 20
Chapter 2 Radio Frequency Fundamentals 23
What Is an RF (Radio Frequency) Signal? 25
Identifying Radio Frequency Characteristics 25
Polarity 26
Wavelength 27
Frequency 29
Amplitude 30
Phase 31
Identifying RF Behaviors 32
Wave Propagation 32
Absorption 33
Reflection 35
Scattering 36
Refraction 37
Diffraction 38
Loss (Attenuation) 39
Free Space Path Loss 41
Multipath 42
Gain (Amplification) 46
Summary 47
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xii
Contents
Exam Essentials 47
Key Terms 48
Review Questions 49
Answers to Review Questions 53
Chapter 3 Radio Frequency Components, Measurements,
and Mathematics 55
RF Components 57
Transmitter 57
Antenna 58
Receiver 59
Intentional Radiator (IR) 59
Equivalent Isotropically Radiated Power (EIRP) 59
Units of Power and Comparison 60
Watt 61
Milliwatt (mW) 61
Decibel (dB) 61
dBi 63
dBd 65
dBm 65
RF Mathematics 66
Rule of 10s and 3s 67
Received Signal Strength Indicator (RSSI) 76
System Operating Margin (SOM)/Link Budget 77
Fade Margin 80
Inverse Square Law 81
Summary 81
Exam Essentials 83
Key Terms 83
Review Questions 84
Answers to Review Questions 88
Chapter 4 Radio Frequency Signal and Antenna Concepts 91
Active and Passive Gain 93
Azimuth and Elevation Chart 94
Beamwidth 96
Antenna Types 97
Omni-directional Antennas 98
Semi-directional Antennas 100
Highly-directional Antennas 103
Phased Array 104
Sector
Antennas 104
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Contents
xiii
Visual Line of Sight 105
RF Line of Sight 105
Fresnel Zone 106
Earth Bulge 109
Antenna Polarization 111
Antenna Diversity 111
Multiple Input Multiple Output (MIMO) 113
Antenna Connection and Installation 113
Voltage Standing Wave Ratio (VSWR) 113
Antenna Mounting 115
Antenna Accessories 118
Cables 118
Connectors 119
Splitters 120
Amplifiers 120
Attenuators 121
Lightning Arrestors 121
Grounding Rods and Wires 123
Summary 125
Exam Essentials 125
Key Terms 126
Review Questions 127
Answers to Review Questions 131
Chapter 5 IEEE 802.11 Standards 133
Overview of the IEEE 802.11 Standard 135
IEEE 802.11 Ratified Amendments 136
802.11b Amendment 136
802.11a Amendment 137
802.11g 139
802.11d 141
802.11F 142
802.11h 144
802.11i 145
802.11j 146
802.11e 147
IEEE 802.11 Draft Amendments 148
802.11k 148
802.11m 149
802.11n 149
802.11p 150
802.11r 150
802.11s 151
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xiv
Contents
802.11T 151
802.11u 152
802.11v 153
802.11w 153
Summary 154
Exam Essentials 154
Key Terms 155
Review Questions 157
Answers to Review Questions 161
Chapter 6 Wireless Networks and Spread Spectrum
Technologies 163
Industrial, Scientific, and Medical (ISM) Bands 165
900 MHz ISM Band 165
2.4 GHz ISM Band 166
5.8 GHz ISM Band 166
Unlicensed National Information Infrastructure Bands (UNII) 166
Lower Band (UNII-1) 167
Middle Band (UNII-2) 167
Upper Band (UNII-3) 167
Narrowband and Spread Spectrum 168
Frequency Hopping Spread Spectrum (FHSS) 170
Hopping Sequence 170
Dwell Time 171
Hop Time 171
Modulation 172
802.11/b/g Channels 172
Direct Sequence Spread Spectrum (DSSS) 176
DSSS Data Encoding 176
Modulation 177
Packet Binary Convolutional Code (PBCC) 178
Orthogonal Frequency Division Multiplexing (OFDM) 178
Convolution Coding 180
802.11a Channels 181
Throughput vs. Bandwidth 182
Communication Resilience 183
Summary 183
Exam Essentials 184
Key Terms 185
Review Questions 186
Answers to Review Questions 190
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Contents
xv
Chapter 7 Wireless LAN Topologies 193
Wireless Networking Topologies 194
Wireless Wide Area Network (WWAN) 195
Wireless Metropolitan Area Network (WMAN) 195
Wireless Personal Area Network (WPAN) 196
Wireless Local Area Network (WLAN) 197
802.11 Topologies 197
Access Point 198
Client Stations 199
Distribution System (DS) 199
Wireless Distribution System (WDS) 200
Service Set Identifier (SSID) 201
Basic Service Set (BSS) 202
Basic Service Set Identifier (BSSID) 203
Basic Service Area (BSA) 203
Extended Service Set (ESS) 204
Independent Basic Service Set (IBSS) 206
Nonstandard 802.11 Topologies 207
802.11 Configuration Modes 208
Access Point Modes 208
Client Station Modes 209
Summary 209
Exam Essentials 210
Key Terms 211
Review Questions 212
Answers to Review Questions 216
Chapter 8 802.11 Medium Access 219
CSMA/CA vs. CSMA/CD 221
Distributed Coordination Function (DCF) 222
Interframe Space (IFS) 223
Collision Detection 223
Duration/ID Field 224
Carrier Sense 224
Random Backoff Time 225
Distributed Coordination Function (DCF) Flowchart 226
Point Coordination Function (PCF) 228
802.11 Frame Format vs. 802.3 Frame Format 229
Three Frame Types 229
Management Frames 230
Control Frames 230
Data Frames 231
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xvi
Contents
Layer 3 Integration with 802.11 Frames 231
Beacon Management Frame (Beacon) 232
Passive Scanning 232
Active Scanning 233
Authentication 234
Open System Authentication 235
Shared Key Authentication 236
Association 237
Authentication and Association States 238
Roaming 240
Reassociation 240
Disassociation 241
Deauthentication 241
Summary 242
Exam Essentials 242
Key Terms 243
Review Questions 244
Answers to Review Questions 248
Chapter 9 802.11 MAC Architecture 251
ACK Frame 252
Fragmentation 253
802.11g Protection Mechanism 255
RTS/CTS 257
CTS-to-Self 260
Power Management 260
Active Mode 261
Power Save Mode 261
Traffic Indication Map (TIM) 261
Delivery Traffic Indication Message (DTIM) 262
Announcement Traffic Indication Message (ATIM) 263
Wireless Multimedia (WMM) 263
Summary 265
Exam Essentials 266
Key Terms 267
Review Questions 268
Answers to Review Questions 272
Chapter 10 Wireless Devices 275
Wireless LAN Client Devices 276
Radio Card Formats 276
Radio Card Chipsets 280
Client Utilities 281
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Contents
xvii
Progression of WLAN Architecture 283
Access Point–Intelligent Edge Architecture 284
Wireless Network Management System (WNMS) 285
Centralized WLAN Architecture 286
Distributed WLAN Architecture 288
Unified WLAN Architecture 289
Specialty WLAN Infrastructure Devices 289
Wireless Workgroup Bridge 289
Wireless LAN Bridges 290
Enterprise Wireless Gateway 292
Residential Wireless Gateway 294
VPN Wireless Router 295
Wireless LAN Mesh Routers 295
Enterprise Encryption Gateway 295
Virtual AP System 297
Power over Ethernet (PoE) 297
PoE Devices 297
Endspan 298
Midspan 298
Summary 298
Exam Essentials 299
Key Terms 300
Review Questions 301
Answers to Review Questions 306
Chapter 11 Network Design, Implementation, and
Management 309
Core, Distribution, and Access 310
Capacity vs. Coverage 311
Corporate Data Access and End User Mobility 313
Network Extension to Remote Areas 313
Bridging—Building-to-Building Connectivity 314
Wireless ISP (WISP) 314
Small Office, Home Office (SOHO) 315
Mobile Office Networking 315
Educational/Classroom Use 316
Industrial—Warehousing and Manufacturing 316
Healthcare—Hospitals and Offices 317
Public Network Access 317
Summary 318
Exam Essentials 319
Key Terms 319
Review Questions 320
Answers to Review Questions 324
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xviii
Contents
Chapter 12 WLAN Troubleshooting 327
802.11 Coverage Considerations 328
Dynamic Rate Switching 329
Roaming 331
Layer 3 Roaming 333
Co-Channel Interference 334
Channel Reuse 336
Hidden Node 338
Near/Far 343
Interference 343
Performance 345
Weather 346
Summary 347
Exam Essentials 347
Key Terms 348
Review Questions 349
Answers to Review Questions 353
Chapter 13 802.11 Network Security Architecture 357
802.11 Security Basics 359
Encryption 360
AAA 360
Segmentation 361
Legacy 802.11 Security 361
Legacy Authentication 361
Static WEP Encryption 362
MAC Filters 365
SSID Cloaking 365
Authentication and Authorization 366
802.1X/EAP Framework 366
EAP Types 368
Dynamic Encryption Key Generation 369
WPA/802.11i 370
Robust Security Network (RSN) 371
4-Way Handshake 372
WPA/WPA2 Personal 372
TKIP 373
CCMP 373
Segmentation 374
VLANs 374
RBAC 374
Infrastructure Security 375
Physical Security 375
Interface Security 376
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Contents
xix
VPN Wireless Security 376
Layer 3 VPNs 376
Summary 378
Exam Essentials 378
Key Terms 379
Review Questions 380
Answers to Review Questions 384
Chapter 14 Wireless Attacks, Intrusion Monitoring, and Policy 387
Wireless Attacks 388
Rogue Access Point 389
Peer-to-Peer Attacks 390
Eavesdropping 390
Encryption Cracking 393
Authentication Attacks 393
MAC Spoofing 394
Management Interface Exploits 395
Wireless Hijacking 395
Denial of Service (DoS) 396
Intrusion Monitoring 398
Wireless Intrusion Detection System (WIDS) 398
Wireless Intrusion Prevention System (WIPS) 401
Mobile WIDS 402
Spectrum Analyzer 403
Wireless Security Policy 404
General Security Policy 404
Functional Security Policy 405
Legislative Compliance 405
802.11 Wireless Policy Recommendations 406
Summary 407
Exam Essentials 408
Key Terms 408
Review Questions 409
Answers to Review Questions 413
Chapter 15 Radio Frequency Site Survey Fundamentals 417
WLAN Site Survey Interview 418
Customer Briefing 418
Business Requirements 419
Capacity and Coverage Requirements 420
Existing Wireless Network 422
Infrastructure Connectivity 423
Security Expectations 425
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xx
Contents
Documents and Reports 426
Forms and Customer Documentation 426
Deliverables 428
Additional Reports 429
Vertical Market Considerations 430
Outdoor Surveys 430
Aesthetics 431
Government 431
Education 431
Healthcare 432
Hotspots 432
Retail 432
Warehouses 433
Manufacturing 433
Multitenant Buildings 434
Summary 434
Exam Essentials 434
Key Terms 435
Review Questions 436
Answers to Review Questions 441
Chapter 16 Site Survey Systems and Devices 443
Site Survey Defined 444
Mandatory Spectrum Analysis 445
Mandatory Coverage Analysis 449
AP Placement and Configuration 453
Optional Application Analysis 454
Site Survey Tools 455
Indoor Site Surveys Tools 456
Outdoor Site Survey Tools 457
Coverage Analysis 460
Manual 460
Assisted 464
Predictive 465
Self-Organizing Wireless LANs 466
Summary 467
Exam Essentials 467
Key Terms 468
Review Questions 469
Answers to Review Questions 474
Glossary
477
Index 509
89526book.fm Page xx Tuesday, July 25, 2006 2:24 PM
Table of Exercises
Exercise 2.1
Visual Demonstration of Absorption . . . . . . . . . . . . . . . 40
Exercise 2.2
Visual Demonstration of Multipath and Phase . . . . . . . . . . . 44
Exercise 3.1
Step-by-Step Procedure . . . . . . . . . . . . . . . . . . . . . 67
Exercise 3.2
Rule of 10s and 3s Example 1 . . . . . . . . . . . . . . . . . . 69
Exercise 3.3
Rule of 10s and 3s Example 2 . . . . . . . . . . . . . . . . . . 70
Exercise 3.4
Rule of 10s and 3s Example 3 . . . . . . . . . . . . . . . . . . 73
Exercise 3.5
Rule of 10s and 3s Example 4 . . . . . . . . . . . . . . . . . . 75
Exercise 8.1
Frame Analysis . . . . . . . . . . . . . . . . . . . . . . . 239
Exercise 16.1
Spectrum Analysis . . . . . . . . . . . . . . . . . . . . . . 446
Exercise 16.2
Link Budget and Fade Margin . . . . . . . . . . . . . . . . . 459
Exercise 16.3
Cable Loss Calculations . . . . . . . . . . . . . . . . . . . . 459
Exercise 16.4
Manual Coverage Analysis . . . . . . . . . . . . . . . . . . 463
Exercise 16.5
Predictive Coverage Analysis . . . . . . . . . . . . . . . . . 466
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89526book.fm Page xxii Tuesday, July 25, 2006 2:24 PM
Introduction
If you have purchased this book or if you are thinking about purchasing this book, then you
probably have some interest in taking the CWNA
®
(Certified Wireless Network Administra-
tor) certification exam or in learning more about what the CWNA certification exam is about.
The authors would like to congratulate you on this first step, and we hope that our book can
help you on your journey. Wireless networking is currently one of the hottest technologies on
the market. As with many fast-growing technologies, the demand for knowledgeable people
is often greater than the supply. The CWNA certification is one way to prove that you have
the knowledge and skills to support this growing industry. This study guide was written with
that goal in mind.
This book was written to help teach you about wireless networking so that you have the
knowledge needed to not only pass the CWNA certification test, but to also be able to design,
install, and support wireless networks. We have included review questions at the end of each
chapter to help you test your knowledge and prepare for the test. We have also included labs,
white papers, videos, and presentations on the CD to further facilitate your learning.
Before we tell you about the certification process and requirements, we must mention that
this information may have changed by the time you are taking your test. We recommend that
you visit
www.cwnp.com
as you prepare to study for your test to determine what the current
objectives and requirements are.
Don’t just study the questions and answers! The practice questions in this
book are designed to test your knowledge of a concept or objective that is
likely to be on the CWNA certification. The practice questions will be different
than the actual certification questions. If you learn and understand the topics
and objectives, you will be better prepared for the test.
About CWNA
®
and CWNP
®
If you have ever prepared to take a certification test for a technology that you are unfamiliar
with, you know that you are not only studying to learn a different technology, but you are
probably also learning about an industry that you are unfamiliar with. Read on and we will
tell you about the CWNP Program.
CWNP
is an abbreviation for
Certified Wireless Network
Professional
. There is no CWNP test. CWNP is the umbrella for the certification program that
is offered by Planet3 Wireless, Inc. (Planet3). Planet3 is a privately held Georgia (U.S.) com-
pany that created the CWNP certifications and courses. The CWNP certification program is
a vendor-neutral program.
The objective of the CWNP Program is to certify people on wireless networking, not on a
specific vendor’s product. Yes, at times the authors of this book and the creators of the certi-
fication will talk about, demonstrate, or even teach how to use a specific product; however,
the goal is the overall understanding of wireless, not the product itself. If you learned to drive
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xxiv
Introduction
a car, you had to physically sit and practice in one. When you think back and reminisce, you
probably don’t tell someone you learned to drive a Ford; you probably say you learned to drive
using a Ford.
There are six wireless certifications offered by the CWNP Program:
Wireless#
TM
(“wireless sharp”)
The Wireless# certification is an entry-level certification focus-
ing on Wi-Fi, Bluetooth, WiMAX, ZigBee, RFID, VoWLAN, and infrared wireless networks.
The Wireless# exam (PW0-050) covers a moderate level of detail on a broad base of wireless
technologies.
CWNA
®
, Certified Wireless Network Administrator
The CWNA certification is a foundation-
level Wi-Fi certification; however, it is not considered an “entry-level” technology certification.
Individuals taking this exam (exam #PW0-100) typically have a solid grasp on network basics
such as the OSI model, IP addressing, PC hardware, and network operating systems. Many of
these candidates already hold other industry-recognized certifications, such as the CompTIA Net-
work+ or Cisco CCNA, and are looking for the CWNA certification to enhance or complement
existing skills.
CWSP
®
, Certified Wireless Security Professional
The CWSP certification exam (PW0-200)
is focused on standards-based wireless security protocols, security policy, and secure wireless
network design. This certification introduces candidates to many of the technologies and tech-
niques that intruders use to compromise wireless networks and administrators use to protect
wireless networks. With recent advances in wireless security, WLANs can be secured beyond
their wired counterparts.
CWAP
®
, Certified Wireless Analysis Professional
The CWAP certification exam (PW0-205)
measures your ability to analyze and troubleshoot wireless LANs. Before taking the exam, you
should understand the frame structures and exchange processes for each of the 802.11 series
of standards and how to use the tools that are available for analyzing and troubleshooting
today’s wireless LANs.
CWNE
®
, Certified Wireless Network Expert
The CWNE certification focuses on advanced
WLAN analysis, design, troubleshooting, quality of service (QoS) mechanisms, spectrum man-
agement, and extensive knowledge of the IEEE 802.11 standard as amended. This certification
is the pinnacle of the WLAN certification industry, and the exam is sure to be demanding.
CWNT
®
, Certified Wireless Network Trainer
Certified Wireless Network Trainers are qual-
ified instructors certified by the CWNP Program to deliver CWNP training courses to IT profes-
sionals. CWNTs are technical and instructional experts in wireless technologies, products, and
solutions. To ensure a superior learning experience for our customers, CWNP Education Partners
are required to use CWNTs when delivering training using Official CWNP Courseware.
Effective January 1, 2007, all material from the existing CWAP exam will be
integrated into the CWNE certification.
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Introduction
xxv
How to Become a CWNA
To become a CWNA, you must do the following two things: agree that you have read and will
abide by the terms and conditions of the CWNP Confidentiality Agreement, and pass the
CWNA certification test.
A copy of the CWNP Confidentiality Agreement can be found online at the
CWNP website.
When you sit to take the test, you will be required to accept this confidentiality agreement
before you can continue with the test. Once you have agreed, you will be able to continue with
the test, and if you pass the test, you are then a CWNA.
The information for the exam is as follows:
Exam Name: Wireless LAN Administrator
Exam Number: PW0-100
Cost: $175.00 (in U.S. dollars)
Duration: 90 minutes
Questions: 60
Question Types: Multiple choice/multiple answer
Passing Score: 70% (80% for instructors)
Available Languages: English
Availability: Register at Pearson VUE (
www.vue.com/cwnp
) or Thompson Prometric
(
www.2test.com
)
When you schedule the exam, you will receive instructions regarding appointment and can-
cellation procedures, ID requirements, and information about the testing center location. In
addition, you’ll receive a registration and payment confirmation letter. Exams can be sched-
uled weeks in advance or, in some cases, even as late as the same day.
After you have successfully passed the CWNA exam, the CWNP Program will award you a
certification that is good for three years. To recertify, you will need to pass the current PW0-100
exam, the CWSP exam, or the CWNE exam. If the information you provided the testing center
is correct, you will receive an e-mail from CWNP recognizing your accomplishment and provid-
ing you with a CWNP certification number. After you earn any CWNP certification, you can
request a certification kit. The kit includes a congratulatory letter, a certificate, and a wallet-
sized personalized ID card. You will need to log in to the CWNP tracking system, verify your
contact information, and request your certification kit.
Who Should Buy This Book?
If you want to acquire a solid foundation in wireless networking and your goal is to prepare
for the exam, this book is for you. You will find clear explanations of the concepts you need
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xxvi
Introduction
to grasp and plenty of help to achieve the high level of professional competency you need in
order to succeed.
If you want to become certified as a CWNA, this book is definitely what you need. However,
if you just want to attempt to pass the exam without really understanding wireless, this study
guide isn’t for you. It’s written for people who want to acquire hands-on skills and in-depth
knowledge of wireless networking.
How to Use This Book and the CD
We’ve included several testing features in the book and on the CD-ROM. These tools will help
you retain vital exam content as well as prepare to sit for the actual exam.
Before You Begin
At the beginning of the book (right after this introduction) is an assessment
test you can use to check your readiness for the exam. Take this test before you start reading the
book; it will help you determine the areas you may need to brush up on. The answers to the
assessment test appear on a separate page after the last question of the test. Each answer includes
an explanation and a note telling you the chapter in which the material appears.
Chapter Review Questions
To test your knowledge as you progress through the book, there
are review questions at the end of each chapter. As you finish each chapter, answer the review
questions and then check your answers—the correct answers appear on the page following the
last review question. You can go back to reread the section that deals with each question you
got wrong to ensure that you answer correctly the next time you’re tested on the material.
Electronic Flashcards
You’ll find flashcard questions on the CD for on-the-go review. These are
short questions and answers, just like the flashcards you probably used in school. You can answer
them on your PC or download them onto a Palm device for quick and convenient reviewing.
Test Engine
The CD also contains the Sybex Test Engine. With this custom test engine, you
can identify weak areas up front and then develop a solid studying strategy that includes each
of the robust testing features described previously. Our thorough readme file will walk you
through the quick, easy installation process.
In addition to the assessment test and the chapter review questions, you’ll find two sample
exams. Use the test engine to take these practice exams just as if you were taking the actual
exam (without any reference material). When you’ve finished the first exam, move on to the
next one to solidify your test-taking skills. If you get more than 95 percent of the answers cor-
rect, you’re ready to take the certification exam.
Full Text of the Book in PDF
The CD-ROM contains this book in PDF (Adobe Reader) for-
mat so you can easily read it on any computer. If you have to travel but still need to study for
the exam, and you have a laptop with a CD-ROM drive, you can carry this entire book with you.
Labs and Exercises
Several chapters in this book have labs that use software, spreadsheets,
and videos that are also provided on the CD-ROM that is included with this book. These
labs and exercises will provide you with a broader learning experience by providing hands-
on experience and step-by-step problem solving.
Extra CWNA certification practice test questions can be found at
www.sybex.com
.
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Introduction
xxvii
Exam Objectives
The CWNA exam measures your understanding of the fundamentals of RF behavior, your abil-
ity to describe the features and functions of wireless LAN components, and your knowledge of
the skills needed to install, configure, and troubleshoot wireless LAN hardware peripherals and
protocols.
The skills and knowledge measured by this examination are derived from a survey of wireless
networking experts and professionals. The results of this survey were used in weighing the subject
areas and ensuring that the weighting is representative of the relative importance of the content.
The following chart provides the breakdown of the exam, showing you the weight of each
section:
Radio Frequency (RF) Technologies—21%
1.1. RF Fundamentals
1.1.1. Define and explain the basic concepts of RF behavior.
Gain
Loss
Reflection
Refraction
Diffraction
Scattering
VSWR
Return loss
Amplification
Attenuation
Absorption
Subject Area % of Exam
Radio Frequency (RF) Technologies 21%
802.11 Regulations and Standards 12%
802.11 Protocols and Devices 14%
802.11 Network Implementation 21%
802.11 Network Security 16%
802.11 RF Site Surveying 16%
Total 100%
89526book.fm Page xxvii Tuesday, July 25, 2006 2:24 PM
xxviii
Introduction
Wave propagation
Free space path loss
Delay spread
1.2. RF Mathematics
1.2.1. Understand and apply the basic components of RF mathematics.
Watt
Milliwatt
Decibel (dB)
dBm
dBi
dBd
RSSI
System operating margin (SOM)
Fade margin
Link budget
Intentional radiator
Equivalent isotropically radiated power (EIRP)
1.3. RF Signal and Antenna Concepts
1.3.1. Identify RF signal characteristics, the applications of basic RF antenna concepts,
and the implementation of solutions that require RF antennas.
Visual LOS
RF LOS
The Fresnel zone
Beamwidths
Azimuth and elevation
Passive gain
Isotropic radiator
Polarization
Antenna diversity
Wavelength
Frequency
Amplitude
Phase
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