CWNA Certified Wireless Network Administrator Study Guide
Exam CWNA-108
Sybex Study Guide
6. Edition April 2021
1088 Pages, Softcover
Textbook
ISBN:
978-1-119-73450-5
John Wiley & Sons
The #1 selling Wi-Fi networking reference guide in the world
The CWNA: Certified Wireless Network Administrator Study Guide is the ultimate preparation resource for the CWNA exam. Fully updated to align with the latest version of the exam, this book features expert coverage of all exam objectives to help you pass the exam. But passing the exam is just a first step. For over 16 years, the CWNA Study Guide has helped individuals jump-start their wireless networking careers. Wireless networking professionals across the globe use this book as their workplace reference guide for enterprise Wi-Fi technology.
Owning this book provides you with a foundation of knowledge for important Wi-Fi networking topics, including:
* Radio frequency (RF) fundamentals
* 802.11 MAC and medium access
* Wireless LAN topologies and architecture
* WLAN design, troubleshooting and validation
* Wi-Fi networking security
The book authors have over 40 years of combined Wi-Fi networking expertise and provide real-world insights that you can leverage in your wireless networking career. Each of the book's 20 chapters breaks down complex topics into easy to understand nuggets of useful information. Each chapter has review questions that help you gauge your progress along the way. Additionally, hands-on exercises allow you to practice applying CWNA concepts to real-world scenarios. You also get a year of free access to the Sybex online interactive learning environment, which features additional resources and study aids, including bonus practice exam questions.
The CWNA certification is a de facto standard for anyone working with wireless technology. It shows employers that you have demonstrated competence in critical areas, and have the knowledge and skills to perform essential duties that keep their wireless networks functioning and safe. The CWNA: Certified Wireless Network Administrator Study Guide gives you everything you need to pass the exam with flying colors.
Foreword xxxv
Introduction xxxvii
Assessment Test lvi
Chapter 1 Overview of Wireless Standards, Organizations, and Fundamentals 1
History of Wireless Local Area Networks 3
Standards Organizations 5
Federal Communications Commission 5
International Telecommunication Union Radiocommunication Sector 6
Institute of Electrical and Electronics Engineers 8
Internet Engineering Task Force 9
Wi-Fi Alliance 11
International Organization for Standardization 21
Core, Distribution, and Access 22
Communications Fundamentals 24
Communication Terminology 24
Understanding Carrier Signals 25
Understanding Keying Methods 27
Summary 33
Exam Essentials 33
Review Questions 34
Chapter 2 IEEE 802.11 Standard and Amendments 39
Original IEEE 802.11 Standard 42
IEEE 802.11-2020 Ratified Amendments 44
802.11a-1999 45
802.11b-1999 46
802.11d-2001 47
802.11e-2005 47
802.11g-2003 48
802.11h-2003 50
802.11i-2004 52
802.11j-2004 53
802.11k-2008 53
802.11n-2009 54
802.11p-2010 55
802.11r-2008 55
802.11s-2011 56
802.11u-2011 57
802.11v-2011 58
802.11w-2009 58
802.11y-2008 59
802.11z-2010 59
802.11aa-2012 59
802.11ac-2013 59
802.11ad-2012 60
802.11ae-2012 61
802.11af-2014 61
802.11ah-2016 62
802.11ai-2016 63
802.11aj-2018 63
802.11ak-2018 63
802.11aq-2018 63
IEEE 802.11 Draft Amendments 63
802.11ax (High Efficiency) 64
802.11ay (Next-Generation 60 GHz) 65
802.11az (Next-Generation Positioning) 65
802.11ba (Wake-Up Radio) 65
802.11bb (Light Communications) 65
802.11bc (Enhanced Broadcast Service) 65
802.11bd (Enhancements for Next-Generation V2X) 65
802.11be (Extremely High Throughput) 66
Defunct Amendments 66
802.11F 66
802.11T 67
IEEE Task Group m 68
Summary 69
Exam Essentials 69
Review Questions 70
Chapter 3 Radio Frequency Fundamentals 75
What is a Radio Frequency Signal? 77
Radio Frequency Characteristics 78
Wavelength 78
Frequency 83
Amplitude 85
Phase 86
Radio Frequency Behaviors 87
Wave Propagation 87
Absorption 88
Reflection 89
Scattering 91
Refraction 91
Diffraction 92
Loss (Attenuation) 94
Free Space Path Loss 96
Multipath 98
Gain (Amplification) 101
RF Analysis Tools 102
Summary 103
Exam Essentials 103
Review Questions 104
Chapter 4 Radio Frequency Components, Measurements, and Mathematics 109
Components of RF Communications 112
Transmitter 112
Antenna 113
Receiver 114
Intentional Radiator 114
Equivalent Isotropically Radiated Power 114
Units of Power and Comparison 115
Watt 116
Milliwatt 117
Decibel 117
Decibels Relative to an Isotropic Radiator (dBi) 120
Decibels Relative to a Half-Wave Dipole Antenna (dBd) 120
Decibels Relative to 1 Milliwatt (dBm) 121
Inverse Square Law 122
RF Mathematics 123
Rule of 10s and 3s 124
RF Math Summary 129
Noise Floor 130
Signal-to-Noise Ratio 130
Signal-to-Interference-Plus-Noise Ratio 131
Received Signal Strength Indicator 131
Link Budget 135
Fade Margin/System Operating Margin 138
Summary 140
Exam Essentials 142
Review Questions 143
Chapter 5 Radio Frequency Signal and Antenna Concepts 147
Azimuth and Elevation Charts (Antenna Radiation Envelopes) 150
Interpreting Polar Charts 152
Beamwidth 155
Antenna Types 157
Omnidirectional Antennas 158
Downtilt Omnidirectional Antennas 161
Semidirectional Antennas 162
Highly Directional Antennas 164
Sector Antennas 166
Antenna Arrays 167
Visual Line of Sight 169
RF Line of Sight 169
Fresnel Zone 170
Earth Bulge 174
Antenna Polarization 175
Antenna Diversity 176
Multiple-Input, Multiple-Output 177
MIMO Antennas 178
Antenna Connection and Installation 179
Voltage Standing Wave Ratio 179
Signal Loss 181
Antenna Mounting 181
Antenna Accessories 187
Cables 188
Connectors 188
Splitters 189
Amplifiers 189
Attenuators 190
Lightning Arrestors 191
Grounding Rods and Wires 192
Regulatory Compliance 192
Summary 194
Exam Essentials 194
Review Questions 195
Chapter 6 Wireless Networks and Spread Spectrum Technologies 199
Throughput vs. Bandwidth 201
Narrowband and Spread Spectrum 202
Multipath Interference 204
Frequency-Hopping Spread Spectrum 205
Hopping Sequence 206
Dwell Time 207
Hop Time 207
Modulation 207
Direct-Sequence Spread Spectrum 208
DSSS Data Encoding 208
Modulation 209
Transmit Spectrum Mask 210
Orthogonal Frequency-Division Multiplexing 211
Convolutional Coding 212
Modulation 213
Transmit Spectrum Mask 215
Orthogonal Frequency-Division Multiple Access 217
Industrial, Scientific, and Medical Bands 218
900 MHz ISM Band 218
2.4 GHz ISM Band 219
5.8 GHz ISM Band 219
5 GHz Unlicensed National Information Infrastructure Bands 220
U-NII-1 220
U-NII-2A 221
U-NII-2C 221
U-NII-3 222
U-NII-4 222
60 GHz for Wi-Fi 223
Below 1 GHz 224
2.4 GHz Channels 224
5 GHz Channels 227
Long-Term Evolution in 5 GHz 231
6 GHz Channels 232
6 GHz Incumbents 235
Automated Frequency Coordination 236
6 GHz Worldwide 237
6 GHz Wi-Fi Considerations 238
Summary 239
Exam Essentials 239
Review Questions 240
Chapter 7 Wireless LAN Topologies 245
Wireless Networking Topologies 247
Wireless Wide Area Network 248
Wireless Metropolitan Area Network 248
Wireless Personal Area Network 249
Wireless Local Area Network 250
802.11 Stations 251
Client Station 252
Access Point Station 252
Integration Service 252
Distribution System 253
Wireless Distribution System 254
802.11 Service Sets 255
Service Set Identifier 256
Basic Service Set 256
Basic Service Area 257
Basic Service Set Identifier 258
Multiple Basic Service Set Identifiers 259
Extended Service Set 261
Independent Basic Service Set 262
Personal Basic Service Set 264
Mesh Basic Service Set 264
QoS Basic Service Set 266
802.11 Configuration Modes 267
Access Point Modes 267
Client Station Modes 268
Summary 269
Exam Essentials 269
Review Questions 271
Chapter 8 802.11 Medium Access 275
CSMA/CA vs. CSMA/CD 276
Collision Detection 277
Distributed Coordination Function 278
Physical Carrier Sense 279
Virtual Carrier Sense 280
Pseudo-Random Backoff Timer 283
Interframe Space 285
Hybrid Coordination Function 286
Enhanced Distributed Channel Access 287
HCF Controlled Channel Access 288
Wi-Fi Multimedia 288
Airtime Fairness 290
Summary 292
Exam Essentials 292
Review Questions 293
Chapter 9 802.11 MAC 297
Packets, Frames, and Bits 299
Data-Link Layer 300
MAC Service Data Unit 300
MAC Protocol Data Unit 300
Physical Layer 301
PLCP Service Data Unit 301
PLCP Protocol Data Unit 302
802.11 and 802.3 Interoperability 302
802.11 MAC Header 303
Frame Control Field 304
Duration/ID Field 306
MAC Layer Addressing 307
Sequence Control Field 314
QoS Control Field 315
HT Control Field 315
802.11 Frame Body 315
802.11 Trailer 316
802.11 State Machine 317
Management Frames 318
Beacon 318
Authentication 325
Association 326
Reassociation 329
Disassociation 331
Deauthentication 331
Action Frame 331
Control Frames 333
ACK Frame 333
Block Acknowledgment 335
PS-Poll 336
RTS/CTS 336
CTS-to-Self 338
Protection Mechanisms 338
Data Frames 341
QoS and Non-QoS Data Frames 342
Non-Data Carrying Frames 343
Power Management 344
Legacy Power Management 345
WMM-Power Save and U-APSD 347
MIMO Power Management 349
802.11ax Power Management 349
Summary 350
Exam Essentials 350
Review Questions 352
Chapter 10 MIMO Technology: HT and VHT 357
MIMO 360
Radio Chains 362
Spatial Multiplexing 363
MIMO versus SISO diversity 366
Maximal Ratio Combining 366
Space-Time Block Coding 367
Cyclic Shift Diversity 368
Transmit Beamforming 368
Explicit Beamforming 370
Multi-User MIMO 371
Multi-User Beamforming 373
Channels 376
20 MHz Channels 376
40 MHz Channels 377
Forty MHz Intolerant 379
80 MHz and 160 MHz Channels 380
Guard Interval 382
256-QAM Modulation 384
802.11n/ac PPDUs 388
Non-HT 388
HT Mixed 388
VHT 389
802.11n/ac MAC 390
A-MSDU 390
A-MPDU 391
Block Acknowledgment 392
Power Management 392
Modulation and Coding Scheme 394
802.11ac Data Rates 397
HT/VHT Protection Mechanisms 399
HT Protection Modes (0-3) 399
Wi-Fi Alliance Certification 400
Summary 403
Exam Essentials 403
Review Questions 405
Chapter 11 WLAN Architecture 409
WLAN Client Devices 411
802.11 Radio Form Factors 412
802.11 Radio Chipsets 418
Client Utilities 418
Management, Control, and Data Planes 421
Management Plane 422
Control Plane 422
Data Plane 423
WLAN Architecture 423
Autonomous WLAN Architecture 423
Centralized Network Management Systems 425
Centralized WLAN Architecture 427
Distributed WLAN Architecture 434
Hybrid WLAN Architecture 436
Specialty WLAN Infrastructure 437
Enterprise WLAN Branch Routers 437
WLAN Mesh Access Points 438
WLAN Bridges 439
Real-Time Location Systems 441
VoWiFi 443
Cloud Networking 445
Application Programming Interface 448
Transport and Data Formats 449
WLAN APIs 450
Common Applications 450
Infrastructure Management 451
Protocols for Management 452
Summary 456
Exam Essentials 457
Review Questions 458
Chapter 12 Power over Ethernet (PoE) 463
History of PoE 464
Nonstandard PoE 465
IEEE 802.3af 465
IEEE Std 802.3-2005, Clause 33 465
IEEE 802.3at-2009 465
IEEE Std 802.3-2018, Clause 33 466
IEEE 802.3bt-2018 466
PoE Devices 467
Powered Device 467
Power-Sourcing Equipment 469
Endpoint PSE 470
Midspan PSE 476
Planning and Deploying PoE 484
Power Planning 484
Redundancy 487
Downgrade PoE Capabilities 488
802.3bt Power Considerations 488
Summary 490
Exam Essentials 491
Review Questions 492
Chapter 13 WLAN Design Concepts 497
WLAN Coverage Design 499
Received Signal 500
Signal-to-Noise Ratio 501
Dynamic Rate Switching 503
Transmit Power 504
Roaming Design 505
Primary and Secondary Coverage 508
Fast Secure Roaming 509
Layer 3 Roaming 510
Channel Design 512
Adjacent Channel Interference 512
2.4 GHz Channel Reuse 513
Co-Channel Interference 516
5 GHz Channel Reuse 519
DFS Channels 521
40 MHz Channel Design 527
Static Channels and Transmit Power vs. Adaptive RF 529
Single-Channel Architecture 531
Capacity Design 534
High-Density 535
Band Steering 539
Load Balancing 542
Airtime Consumption 543
Voice vs. Data 546
Dual 5 GHz and Software-Defined Radios 548
6 GHz WLAN Design 551
Client Considerations 552
Coverage Considerations 553
6 GHz Channel Reuse 553
6 GHz AP Discovery 554
6 GHz Wi-Fi Security 556
Physical Environment 557
Antennas 558
Outdoor Design 562
Summary 563
Exam Essentials 564
Review Questions 565
Chapter 14 Site Survey and Validation 569
WLAN Site Survey and Design Interview 572
Customer Briefing 572
Business Requirements 573
Capacity and Coverage Requirements 574
Existing Wireless Network 576
Upgrading an Existing WLAN 577
Infrastructure Connectivity 578
Security Expectations 580
Guest Access 581
Aesthetics 581
Outdoor Surveys 582
Vertical Market Considerations 582
Government 583
Education 583
Healthcare 583
Retail 584
Warehouses and Manufacturing 584
Multi-Tenant Buildings 585
Legacy AP-on-a-Stick Survey 585
Spectrum Analysis 586
Coverage Analysis 590
Hybrid Survey 595
Initial Site Visit 595
Predictive Design 597
Validation Survey 599
Capacity and Throughput 601
Roaming 602
Delay and Jitter 603
Connectivity 603
Aesthetics 603
Site Survey Tools 604
Indoor Site Survey Tools 604
Outdoor Site Survey Tools 607
Documents and Reports 609
Forms and Customer Documentation 610
Deliverables 612
Additional Reports 613
Summary 614
Exam Essentials 615
Review Questions 616
Chapter 15 WLAN Troubleshooting 621
Five Tenets of WLAN Troubleshooting 623
Troubleshooting Best Practices 623
Troubleshoot the OSI Model 625
Most Wi-Fi Problems Are Client Issues 627
Proper WLAN Design Reduces Problems 628
WLAN Always Gets the Blame 629
Layer 1 Troubleshooting 629
WLAN Design 629
Transmit Power 630
RF Interference 630
Drivers 634
PoE 635
Firmware Bugs 635
Layer 2 Troubleshooting 636
Layer 2 Retransmissions 636
RF Interference 639
Low SNR 639
Adjacent Channel Interference 640
Hidden Node 641
Mismatched Power 646
Multipath 648
Security Troubleshooting 648
PSK Troubleshooting 649
802.1X/EAP Troubleshooting 651
VPN Troubleshooting 659
Roaming Troubleshooting 661
Channel Utilization 665
Layers 3-7 Troubleshooting 667
WLAN Troubleshooting Tools 671
WLAN Discovery Applications 671
Spectrum Analyzers 672
Protocol Analyzers 673
Throughput Test Tools 675
Standard IP Network Test Commands 677
Secure Shell 678
Summary 679
Exam Essentials 679
Review Questions 680
Chapter 16 Wireless Attacks, Intrusion Monitoring, and Policy 687
Wireless Attacks 688
Rogue Wireless Devices 689
Peer-to-Peer Attacks 692
Eavesdropping 693
Encryption Cracking 697
KRACK Attack 698
Kr00k Vulnerability 698
Authentication Attacks 699
MAC Spoofing 701
Management Interface Exploits 701
Wireless Hijacking 702
Denial-of-Service Attacks 703
Vendor-Specific Attacks 705
Social Engineering 706
Intrusion Monitoring 706
Wireless Intrusion Prevention System 706
Rogue Detection and Mitigation 709
Spectrum Analyzers 712
Wireless Security Policies 712
General Security Policies 713
Functional Security Policies 713
Legislative Compliance 714
802.11 Wireless Policy Recommendations 715
Summary 716
Exam Essentials 717
Review Questions 718
Chapter 17 802.11 Network Security Architecture 723
802.11 Security Basics 725
Data Privacy and Integrity 726
Authentication, Authorization, and Accounting 728
Segmentation 728
Monitoring and Policy 729
Legacy 802.11 Security 729
Legacy Authentication 730
Static WEP Encryption 731
MAC Filters 735
SSID Cloaking 735
Robust Security 736
Robust Security Network 737
Authentication and Authorization 738
PSK Authentication 738
Proprietary PSK Authentication 741
Simultaneous Authentication of Equals 743
802.1X/EAP Framework 746
EAP Types 749
Dynamic Encryption-Key Generation 751
4-Way Handshake 752
WLAN Encryption 754
TKIP Encryption 755
CCMP Encryption 756
GCMP Encryption 756
Management Frame Protection 757
WPA2 757
WPA3 758
WPA3-Personal 758
WPA3-Enterprise 759
Enhanced Open 761
6 GHz Wi-Fi Security 762
Traffic Segmentation 763
VLANs 763
RBAC 765
VPN Wireless Security 766
VPN 101 767
Layer 3 VPNs 768
SSL VPNs 768
VPN Deployment 768
Summary 770
Exam Essentials 770
Review Questions 772
Chapter 18 Bring Your Own Device (BYOD) and Guest Access 777
Mobile Device Management 780
Company-Issued Devices vs. Personal Devices 781
MDM Architecture 782
MDM Enrollment 784
MDM Profiles 788
MDM Agent Software 790
Over-the-Air Management 791
Application Management 793
Self-Service Device Onboarding for Employees 795
Dual-SSID Onboarding 796
Single-SSID Onboarding 796
MDM vs. Self-Service Onboarding 797
Guest WLAN Access 798
Guest SSID 798
Guest VLAN 799
Guest Firewall Policy 800
Captive Web Portals 801
Client Isolation, Rate Limiting, and Web Content Filtering 804
Guest Management 805
Guest Self-Registration 806
Employee Sponsorship 808
Social Login 809
Encrypted Guest Access 810
Hotspot 2.0 and Passpoint 811
Access Network Query Protocol 811
Hotspot 2.0 Architecture 813
802.1X/EAP and Hotspot 2.0 814
Online Sign-Up 815
Roaming Agreements 816
Network Access Control 816
Posture 817
OS Fingerprinting 818
AAA 820
RADIUS Change of Authorization 821
Single Sign-On 822
Summary 824
Exam Essentials 825
Review Questions 826
Chapter 19 802.11ax: High Efficiency (HE) 831
802.11ax = Wi-Fi 6 833
Wi-Fi Traffic Congestion 834
HE Overview 836
Multi-User 837
OFDMA 838
Subcarriers 839
Resource Units 840
Trigger Frames 844
Downlink OFDMA 847
Uplink OFDMA 848
Buffer Status Reports 849
Operating Mode Indication 850
MU-MIMO 851
BSS Color and Spatial Reuse 855
OBSS 855
BSS Color 857
Spatial Reuse Operation 858
Target Wake Time 861
Additional 802.11ax PHY and MAC Capabilities 862
1024-QAM 862
Long Symbol Time and Guard Intervals 863
802.11ax PHY headers 864
20 MHz-Only 865
Multi-TID AMPDU 867
Wi-Fi 6 Key Questions 867
Clients 867
Multi-Gig Ethernet 868
Power over Ethernet 870
4×4:4 vs. 8×8:8 871
80 MHz and 160 MHz Channels 872
Wi-Fi CERTIFIED 6 873
Summary 874
Review Questions 875
Chapter 20 WLAN Deployment and Vertical Markets 879
Deployment Considerations for Commonly Supported WLAN Applications and Devices 881
Data 881
Voice 882
Video 882
Real-Time Location Services 883
iBeacon Proximity 883
Mobile Devices 885
Corporate Data Access and End-User Mobility 885
Network Extension to Remote Areas 886
Bridging: Building-to-Building Connectivity 887
Wireless ISP: Last-Mile Data Delivery 888
Small Office/Home Office 888
Temporary Office Networking 889
Branch Offices 890
Teleworker Wi-Fi 890
Educational/Classroom Use 891
Industrial: Warehousing and Manufacturing 892
Retail 892
Healthcare 894
Municipal Networks 895
Hotspots: Public Network Access 895
Stadium Networks 897
Transportation Networks 897
Law Enforcement Networks 898
First-Responder Networks 899
Managed Service Providers 900
Fixed Mobile Convergence 900
WLAN and Health 901
Internet of Things 901
WLAN Vendors 902
Summary 904
Exam Essentials 904
Review Questions 905
Appendix A Answers to Review Questions 909
Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals 910
Chapter 2: IEEE 802.11 Standard and Amendments 911
Chapter 3: Radio Frequency Fundamentals 914
Chapter 4: Radio Frequency Components, Measurements, and Mathematics 915
Chapter 5: Radio Frequency Signal and Antenna Concepts 918
Chapter 6: Wireless Networks and Spread Spectrum Technologies 919
Chapter 7: Wireless LAN Topologies 922
Chapter 8: 802.11 Medium Access 924
Chapter 9: 802.11 MAC 926
Chapter 10: MIMO Technology: HT and VHT 929
Chapter 11: WLAN Architecture 932
Chapter 12: Power over Ethernet (PoE) 934
Chapter 13: WLAN Design Concepts 937
Chapter 14: Site Survey and Validation 940
Chapter 15: WLAN Troubleshooting 943
Chapter 16: Wireless Attacks, Intrusion Monitoring, and Policy 946
Chapter 17: 802.11 Network Security Architecture 948
Chapter 18: Bring Your Own Device (BYOD) and Guest Access 951
Chapter 19: 802.11ax: High Efficiency (HE) 954
Chapter 20: WLAN Deployment and Vertical Markets 957
Appendix B Abbreviations and Acronyms 961
Certifications 962
Organizations and Regulations 962
Measurements 963
Technical Terms 964
Index 981
Introduction xxxvii
Assessment Test lvi
Chapter 1 Overview of Wireless Standards, Organizations, and Fundamentals 1
History of Wireless Local Area Networks 3
Standards Organizations 5
Federal Communications Commission 5
International Telecommunication Union Radiocommunication Sector 6
Institute of Electrical and Electronics Engineers 8
Internet Engineering Task Force 9
Wi-Fi Alliance 11
International Organization for Standardization 21
Core, Distribution, and Access 22
Communications Fundamentals 24
Communication Terminology 24
Understanding Carrier Signals 25
Understanding Keying Methods 27
Summary 33
Exam Essentials 33
Review Questions 34
Chapter 2 IEEE 802.11 Standard and Amendments 39
Original IEEE 802.11 Standard 42
IEEE 802.11-2020 Ratified Amendments 44
802.11a-1999 45
802.11b-1999 46
802.11d-2001 47
802.11e-2005 47
802.11g-2003 48
802.11h-2003 50
802.11i-2004 52
802.11j-2004 53
802.11k-2008 53
802.11n-2009 54
802.11p-2010 55
802.11r-2008 55
802.11s-2011 56
802.11u-2011 57
802.11v-2011 58
802.11w-2009 58
802.11y-2008 59
802.11z-2010 59
802.11aa-2012 59
802.11ac-2013 59
802.11ad-2012 60
802.11ae-2012 61
802.11af-2014 61
802.11ah-2016 62
802.11ai-2016 63
802.11aj-2018 63
802.11ak-2018 63
802.11aq-2018 63
IEEE 802.11 Draft Amendments 63
802.11ax (High Efficiency) 64
802.11ay (Next-Generation 60 GHz) 65
802.11az (Next-Generation Positioning) 65
802.11ba (Wake-Up Radio) 65
802.11bb (Light Communications) 65
802.11bc (Enhanced Broadcast Service) 65
802.11bd (Enhancements for Next-Generation V2X) 65
802.11be (Extremely High Throughput) 66
Defunct Amendments 66
802.11F 66
802.11T 67
IEEE Task Group m 68
Summary 69
Exam Essentials 69
Review Questions 70
Chapter 3 Radio Frequency Fundamentals 75
What is a Radio Frequency Signal? 77
Radio Frequency Characteristics 78
Wavelength 78
Frequency 83
Amplitude 85
Phase 86
Radio Frequency Behaviors 87
Wave Propagation 87
Absorption 88
Reflection 89
Scattering 91
Refraction 91
Diffraction 92
Loss (Attenuation) 94
Free Space Path Loss 96
Multipath 98
Gain (Amplification) 101
RF Analysis Tools 102
Summary 103
Exam Essentials 103
Review Questions 104
Chapter 4 Radio Frequency Components, Measurements, and Mathematics 109
Components of RF Communications 112
Transmitter 112
Antenna 113
Receiver 114
Intentional Radiator 114
Equivalent Isotropically Radiated Power 114
Units of Power and Comparison 115
Watt 116
Milliwatt 117
Decibel 117
Decibels Relative to an Isotropic Radiator (dBi) 120
Decibels Relative to a Half-Wave Dipole Antenna (dBd) 120
Decibels Relative to 1 Milliwatt (dBm) 121
Inverse Square Law 122
RF Mathematics 123
Rule of 10s and 3s 124
RF Math Summary 129
Noise Floor 130
Signal-to-Noise Ratio 130
Signal-to-Interference-Plus-Noise Ratio 131
Received Signal Strength Indicator 131
Link Budget 135
Fade Margin/System Operating Margin 138
Summary 140
Exam Essentials 142
Review Questions 143
Chapter 5 Radio Frequency Signal and Antenna Concepts 147
Azimuth and Elevation Charts (Antenna Radiation Envelopes) 150
Interpreting Polar Charts 152
Beamwidth 155
Antenna Types 157
Omnidirectional Antennas 158
Downtilt Omnidirectional Antennas 161
Semidirectional Antennas 162
Highly Directional Antennas 164
Sector Antennas 166
Antenna Arrays 167
Visual Line of Sight 169
RF Line of Sight 169
Fresnel Zone 170
Earth Bulge 174
Antenna Polarization 175
Antenna Diversity 176
Multiple-Input, Multiple-Output 177
MIMO Antennas 178
Antenna Connection and Installation 179
Voltage Standing Wave Ratio 179
Signal Loss 181
Antenna Mounting 181
Antenna Accessories 187
Cables 188
Connectors 188
Splitters 189
Amplifiers 189
Attenuators 190
Lightning Arrestors 191
Grounding Rods and Wires 192
Regulatory Compliance 192
Summary 194
Exam Essentials 194
Review Questions 195
Chapter 6 Wireless Networks and Spread Spectrum Technologies 199
Throughput vs. Bandwidth 201
Narrowband and Spread Spectrum 202
Multipath Interference 204
Frequency-Hopping Spread Spectrum 205
Hopping Sequence 206
Dwell Time 207
Hop Time 207
Modulation 207
Direct-Sequence Spread Spectrum 208
DSSS Data Encoding 208
Modulation 209
Transmit Spectrum Mask 210
Orthogonal Frequency-Division Multiplexing 211
Convolutional Coding 212
Modulation 213
Transmit Spectrum Mask 215
Orthogonal Frequency-Division Multiple Access 217
Industrial, Scientific, and Medical Bands 218
900 MHz ISM Band 218
2.4 GHz ISM Band 219
5.8 GHz ISM Band 219
5 GHz Unlicensed National Information Infrastructure Bands 220
U-NII-1 220
U-NII-2A 221
U-NII-2C 221
U-NII-3 222
U-NII-4 222
60 GHz for Wi-Fi 223
Below 1 GHz 224
2.4 GHz Channels 224
5 GHz Channels 227
Long-Term Evolution in 5 GHz 231
6 GHz Channels 232
6 GHz Incumbents 235
Automated Frequency Coordination 236
6 GHz Worldwide 237
6 GHz Wi-Fi Considerations 238
Summary 239
Exam Essentials 239
Review Questions 240
Chapter 7 Wireless LAN Topologies 245
Wireless Networking Topologies 247
Wireless Wide Area Network 248
Wireless Metropolitan Area Network 248
Wireless Personal Area Network 249
Wireless Local Area Network 250
802.11 Stations 251
Client Station 252
Access Point Station 252
Integration Service 252
Distribution System 253
Wireless Distribution System 254
802.11 Service Sets 255
Service Set Identifier 256
Basic Service Set 256
Basic Service Area 257
Basic Service Set Identifier 258
Multiple Basic Service Set Identifiers 259
Extended Service Set 261
Independent Basic Service Set 262
Personal Basic Service Set 264
Mesh Basic Service Set 264
QoS Basic Service Set 266
802.11 Configuration Modes 267
Access Point Modes 267
Client Station Modes 268
Summary 269
Exam Essentials 269
Review Questions 271
Chapter 8 802.11 Medium Access 275
CSMA/CA vs. CSMA/CD 276
Collision Detection 277
Distributed Coordination Function 278
Physical Carrier Sense 279
Virtual Carrier Sense 280
Pseudo-Random Backoff Timer 283
Interframe Space 285
Hybrid Coordination Function 286
Enhanced Distributed Channel Access 287
HCF Controlled Channel Access 288
Wi-Fi Multimedia 288
Airtime Fairness 290
Summary 292
Exam Essentials 292
Review Questions 293
Chapter 9 802.11 MAC 297
Packets, Frames, and Bits 299
Data-Link Layer 300
MAC Service Data Unit 300
MAC Protocol Data Unit 300
Physical Layer 301
PLCP Service Data Unit 301
PLCP Protocol Data Unit 302
802.11 and 802.3 Interoperability 302
802.11 MAC Header 303
Frame Control Field 304
Duration/ID Field 306
MAC Layer Addressing 307
Sequence Control Field 314
QoS Control Field 315
HT Control Field 315
802.11 Frame Body 315
802.11 Trailer 316
802.11 State Machine 317
Management Frames 318
Beacon 318
Authentication 325
Association 326
Reassociation 329
Disassociation 331
Deauthentication 331
Action Frame 331
Control Frames 333
ACK Frame 333
Block Acknowledgment 335
PS-Poll 336
RTS/CTS 336
CTS-to-Self 338
Protection Mechanisms 338
Data Frames 341
QoS and Non-QoS Data Frames 342
Non-Data Carrying Frames 343
Power Management 344
Legacy Power Management 345
WMM-Power Save and U-APSD 347
MIMO Power Management 349
802.11ax Power Management 349
Summary 350
Exam Essentials 350
Review Questions 352
Chapter 10 MIMO Technology: HT and VHT 357
MIMO 360
Radio Chains 362
Spatial Multiplexing 363
MIMO versus SISO diversity 366
Maximal Ratio Combining 366
Space-Time Block Coding 367
Cyclic Shift Diversity 368
Transmit Beamforming 368
Explicit Beamforming 370
Multi-User MIMO 371
Multi-User Beamforming 373
Channels 376
20 MHz Channels 376
40 MHz Channels 377
Forty MHz Intolerant 379
80 MHz and 160 MHz Channels 380
Guard Interval 382
256-QAM Modulation 384
802.11n/ac PPDUs 388
Non-HT 388
HT Mixed 388
VHT 389
802.11n/ac MAC 390
A-MSDU 390
A-MPDU 391
Block Acknowledgment 392
Power Management 392
Modulation and Coding Scheme 394
802.11ac Data Rates 397
HT/VHT Protection Mechanisms 399
HT Protection Modes (0-3) 399
Wi-Fi Alliance Certification 400
Summary 403
Exam Essentials 403
Review Questions 405
Chapter 11 WLAN Architecture 409
WLAN Client Devices 411
802.11 Radio Form Factors 412
802.11 Radio Chipsets 418
Client Utilities 418
Management, Control, and Data Planes 421
Management Plane 422
Control Plane 422
Data Plane 423
WLAN Architecture 423
Autonomous WLAN Architecture 423
Centralized Network Management Systems 425
Centralized WLAN Architecture 427
Distributed WLAN Architecture 434
Hybrid WLAN Architecture 436
Specialty WLAN Infrastructure 437
Enterprise WLAN Branch Routers 437
WLAN Mesh Access Points 438
WLAN Bridges 439
Real-Time Location Systems 441
VoWiFi 443
Cloud Networking 445
Application Programming Interface 448
Transport and Data Formats 449
WLAN APIs 450
Common Applications 450
Infrastructure Management 451
Protocols for Management 452
Summary 456
Exam Essentials 457
Review Questions 458
Chapter 12 Power over Ethernet (PoE) 463
History of PoE 464
Nonstandard PoE 465
IEEE 802.3af 465
IEEE Std 802.3-2005, Clause 33 465
IEEE 802.3at-2009 465
IEEE Std 802.3-2018, Clause 33 466
IEEE 802.3bt-2018 466
PoE Devices 467
Powered Device 467
Power-Sourcing Equipment 469
Endpoint PSE 470
Midspan PSE 476
Planning and Deploying PoE 484
Power Planning 484
Redundancy 487
Downgrade PoE Capabilities 488
802.3bt Power Considerations 488
Summary 490
Exam Essentials 491
Review Questions 492
Chapter 13 WLAN Design Concepts 497
WLAN Coverage Design 499
Received Signal 500
Signal-to-Noise Ratio 501
Dynamic Rate Switching 503
Transmit Power 504
Roaming Design 505
Primary and Secondary Coverage 508
Fast Secure Roaming 509
Layer 3 Roaming 510
Channel Design 512
Adjacent Channel Interference 512
2.4 GHz Channel Reuse 513
Co-Channel Interference 516
5 GHz Channel Reuse 519
DFS Channels 521
40 MHz Channel Design 527
Static Channels and Transmit Power vs. Adaptive RF 529
Single-Channel Architecture 531
Capacity Design 534
High-Density 535
Band Steering 539
Load Balancing 542
Airtime Consumption 543
Voice vs. Data 546
Dual 5 GHz and Software-Defined Radios 548
6 GHz WLAN Design 551
Client Considerations 552
Coverage Considerations 553
6 GHz Channel Reuse 553
6 GHz AP Discovery 554
6 GHz Wi-Fi Security 556
Physical Environment 557
Antennas 558
Outdoor Design 562
Summary 563
Exam Essentials 564
Review Questions 565
Chapter 14 Site Survey and Validation 569
WLAN Site Survey and Design Interview 572
Customer Briefing 572
Business Requirements 573
Capacity and Coverage Requirements 574
Existing Wireless Network 576
Upgrading an Existing WLAN 577
Infrastructure Connectivity 578
Security Expectations 580
Guest Access 581
Aesthetics 581
Outdoor Surveys 582
Vertical Market Considerations 582
Government 583
Education 583
Healthcare 583
Retail 584
Warehouses and Manufacturing 584
Multi-Tenant Buildings 585
Legacy AP-on-a-Stick Survey 585
Spectrum Analysis 586
Coverage Analysis 590
Hybrid Survey 595
Initial Site Visit 595
Predictive Design 597
Validation Survey 599
Capacity and Throughput 601
Roaming 602
Delay and Jitter 603
Connectivity 603
Aesthetics 603
Site Survey Tools 604
Indoor Site Survey Tools 604
Outdoor Site Survey Tools 607
Documents and Reports 609
Forms and Customer Documentation 610
Deliverables 612
Additional Reports 613
Summary 614
Exam Essentials 615
Review Questions 616
Chapter 15 WLAN Troubleshooting 621
Five Tenets of WLAN Troubleshooting 623
Troubleshooting Best Practices 623
Troubleshoot the OSI Model 625
Most Wi-Fi Problems Are Client Issues 627
Proper WLAN Design Reduces Problems 628
WLAN Always Gets the Blame 629
Layer 1 Troubleshooting 629
WLAN Design 629
Transmit Power 630
RF Interference 630
Drivers 634
PoE 635
Firmware Bugs 635
Layer 2 Troubleshooting 636
Layer 2 Retransmissions 636
RF Interference 639
Low SNR 639
Adjacent Channel Interference 640
Hidden Node 641
Mismatched Power 646
Multipath 648
Security Troubleshooting 648
PSK Troubleshooting 649
802.1X/EAP Troubleshooting 651
VPN Troubleshooting 659
Roaming Troubleshooting 661
Channel Utilization 665
Layers 3-7 Troubleshooting 667
WLAN Troubleshooting Tools 671
WLAN Discovery Applications 671
Spectrum Analyzers 672
Protocol Analyzers 673
Throughput Test Tools 675
Standard IP Network Test Commands 677
Secure Shell 678
Summary 679
Exam Essentials 679
Review Questions 680
Chapter 16 Wireless Attacks, Intrusion Monitoring, and Policy 687
Wireless Attacks 688
Rogue Wireless Devices 689
Peer-to-Peer Attacks 692
Eavesdropping 693
Encryption Cracking 697
KRACK Attack 698
Kr00k Vulnerability 698
Authentication Attacks 699
MAC Spoofing 701
Management Interface Exploits 701
Wireless Hijacking 702
Denial-of-Service Attacks 703
Vendor-Specific Attacks 705
Social Engineering 706
Intrusion Monitoring 706
Wireless Intrusion Prevention System 706
Rogue Detection and Mitigation 709
Spectrum Analyzers 712
Wireless Security Policies 712
General Security Policies 713
Functional Security Policies 713
Legislative Compliance 714
802.11 Wireless Policy Recommendations 715
Summary 716
Exam Essentials 717
Review Questions 718
Chapter 17 802.11 Network Security Architecture 723
802.11 Security Basics 725
Data Privacy and Integrity 726
Authentication, Authorization, and Accounting 728
Segmentation 728
Monitoring and Policy 729
Legacy 802.11 Security 729
Legacy Authentication 730
Static WEP Encryption 731
MAC Filters 735
SSID Cloaking 735
Robust Security 736
Robust Security Network 737
Authentication and Authorization 738
PSK Authentication 738
Proprietary PSK Authentication 741
Simultaneous Authentication of Equals 743
802.1X/EAP Framework 746
EAP Types 749
Dynamic Encryption-Key Generation 751
4-Way Handshake 752
WLAN Encryption 754
TKIP Encryption 755
CCMP Encryption 756
GCMP Encryption 756
Management Frame Protection 757
WPA2 757
WPA3 758
WPA3-Personal 758
WPA3-Enterprise 759
Enhanced Open 761
6 GHz Wi-Fi Security 762
Traffic Segmentation 763
VLANs 763
RBAC 765
VPN Wireless Security 766
VPN 101 767
Layer 3 VPNs 768
SSL VPNs 768
VPN Deployment 768
Summary 770
Exam Essentials 770
Review Questions 772
Chapter 18 Bring Your Own Device (BYOD) and Guest Access 777
Mobile Device Management 780
Company-Issued Devices vs. Personal Devices 781
MDM Architecture 782
MDM Enrollment 784
MDM Profiles 788
MDM Agent Software 790
Over-the-Air Management 791
Application Management 793
Self-Service Device Onboarding for Employees 795
Dual-SSID Onboarding 796
Single-SSID Onboarding 796
MDM vs. Self-Service Onboarding 797
Guest WLAN Access 798
Guest SSID 798
Guest VLAN 799
Guest Firewall Policy 800
Captive Web Portals 801
Client Isolation, Rate Limiting, and Web Content Filtering 804
Guest Management 805
Guest Self-Registration 806
Employee Sponsorship 808
Social Login 809
Encrypted Guest Access 810
Hotspot 2.0 and Passpoint 811
Access Network Query Protocol 811
Hotspot 2.0 Architecture 813
802.1X/EAP and Hotspot 2.0 814
Online Sign-Up 815
Roaming Agreements 816
Network Access Control 816
Posture 817
OS Fingerprinting 818
AAA 820
RADIUS Change of Authorization 821
Single Sign-On 822
Summary 824
Exam Essentials 825
Review Questions 826
Chapter 19 802.11ax: High Efficiency (HE) 831
802.11ax = Wi-Fi 6 833
Wi-Fi Traffic Congestion 834
HE Overview 836
Multi-User 837
OFDMA 838
Subcarriers 839
Resource Units 840
Trigger Frames 844
Downlink OFDMA 847
Uplink OFDMA 848
Buffer Status Reports 849
Operating Mode Indication 850
MU-MIMO 851
BSS Color and Spatial Reuse 855
OBSS 855
BSS Color 857
Spatial Reuse Operation 858
Target Wake Time 861
Additional 802.11ax PHY and MAC Capabilities 862
1024-QAM 862
Long Symbol Time and Guard Intervals 863
802.11ax PHY headers 864
20 MHz-Only 865
Multi-TID AMPDU 867
Wi-Fi 6 Key Questions 867
Clients 867
Multi-Gig Ethernet 868
Power over Ethernet 870
4×4:4 vs. 8×8:8 871
80 MHz and 160 MHz Channels 872
Wi-Fi CERTIFIED 6 873
Summary 874
Review Questions 875
Chapter 20 WLAN Deployment and Vertical Markets 879
Deployment Considerations for Commonly Supported WLAN Applications and Devices 881
Data 881
Voice 882
Video 882
Real-Time Location Services 883
iBeacon Proximity 883
Mobile Devices 885
Corporate Data Access and End-User Mobility 885
Network Extension to Remote Areas 886
Bridging: Building-to-Building Connectivity 887
Wireless ISP: Last-Mile Data Delivery 888
Small Office/Home Office 888
Temporary Office Networking 889
Branch Offices 890
Teleworker Wi-Fi 890
Educational/Classroom Use 891
Industrial: Warehousing and Manufacturing 892
Retail 892
Healthcare 894
Municipal Networks 895
Hotspots: Public Network Access 895
Stadium Networks 897
Transportation Networks 897
Law Enforcement Networks 898
First-Responder Networks 899
Managed Service Providers 900
Fixed Mobile Convergence 900
WLAN and Health 901
Internet of Things 901
WLAN Vendors 902
Summary 904
Exam Essentials 904
Review Questions 905
Appendix A Answers to Review Questions 909
Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals 910
Chapter 2: IEEE 802.11 Standard and Amendments 911
Chapter 3: Radio Frequency Fundamentals 914
Chapter 4: Radio Frequency Components, Measurements, and Mathematics 915
Chapter 5: Radio Frequency Signal and Antenna Concepts 918
Chapter 6: Wireless Networks and Spread Spectrum Technologies 919
Chapter 7: Wireless LAN Topologies 922
Chapter 8: 802.11 Medium Access 924
Chapter 9: 802.11 MAC 926
Chapter 10: MIMO Technology: HT and VHT 929
Chapter 11: WLAN Architecture 932
Chapter 12: Power over Ethernet (PoE) 934
Chapter 13: WLAN Design Concepts 937
Chapter 14: Site Survey and Validation 940
Chapter 15: WLAN Troubleshooting 943
Chapter 16: Wireless Attacks, Intrusion Monitoring, and Policy 946
Chapter 17: 802.11 Network Security Architecture 948
Chapter 18: Bring Your Own Device (BYOD) and Guest Access 951
Chapter 19: 802.11ax: High Efficiency (HE) 954
Chapter 20: WLAN Deployment and Vertical Markets 957
Appendix B Abbreviations and Acronyms 961
Certifications 962
Organizations and Regulations 962
Measurements 963
Technical Terms 964
Index 981
DAVID D. COLEMAN, CWNE #4, David D. Coleman, CWNE #4, is a technology evangelist and public speaker who specializes in Wi-Fi and cloud technologies. David is also Director of Product Marketing for Extreme Networks. He is the author of numerous books, white papers and videos about Wi-Fi technology. DAVID A. WESTCOTT, CWNE #7, is an independent consultant and WLAN technical trainer of thirty years. He provides vendor and custom wireless training to government agencies, corporations and universities around the world.
