Designing and Deploying 802.11 Wireless Networks Second Edition A Practical Guide to Implementing 802.11n and 802.11ac Wireless Networks For Enterprise-Based Applications Plan, deploy, and operate high-performance 802.11ac and 802.11n wireless networks The new 802.11ac standard enables WLANs to deliver significantly higher performance. Network equipment manufacturers have refocused on 802.11ac- and 802.11n-compliant solutions, rapidly moving older versions of 802.11 toward “legacy” status. Now, there’s a complete guide to planning, designing, installing, testing, and supporting 802.11ac and 802.11n wireless networks in any environment, for virtually any application. Jim Geier offers practical methods, tips, and recommendations that draw on his decades of experience deploying wireless solutions and shaping wireless standards. He carefully introduces 802.11ac’s fundamentally different design, site survey, implementation, and network configuration techniques, helping you maximize performance and avoid pitfalls. Geier organizes each phase of WLAN deployment into clearly defined steps, making the entire planning and deployment process easy to understand and execute. He illuminates key concepts and methods through realistic case studies based on current Cisco products, while offering tips and techniques you can use with any vendor’s equipment. To build your skills with key tasks, you’ll find several hands-on exercises relying on free or inexpensive tools. Whether you’re deploying an entirely new wireless network or migrating from older equipment, this guide contains all the expert knowledge you’ll need to succeed. Jim Geier has 30 years of experience planning, designing, analyzing and implementing communications, wireless, and mobile systems. Geier is founder and Principal Consultant of Wireless-Nets, Ltd., providing wireless analysis and design services to product manufacturers. He is also president, CEO, and co-founder of Health Grade Networks, providing wireless network solutions to hospitals, airports, and manufacturing facilities. His books include the first edition of Designing and Deploying 802.11n Wireless Networks (Cisco Press); as well as Implementing 802.1X Security Solutions and Wireless Networking Handbook. Geier has been active in the IEEE 802.11 Working Group and Wi-Fi Alliance; has chaired the IEEE Computer Society (Dayton Section) and various conferences; and served as expert witness in patent litigation related to wireless and cellular technologies.   Review key 802.11 concepts, applications, markets, and technologies Compare ad hoc, mesh, and infrastructure WLANs and their components Consider the impact of radio signal interference, security vulnerabilities, multipath propagation, roaming, and battery limitations Thoroughly understand today’s 802.11 standards in the context of actual network deployment and support Plan your deployment: scoping, staffing, schedules, budgets, risks, feasibility analysis, and requirements Architect access networks and distribut

Table of Contents:
Introduction xxv Part I: Fundamental Concepts Chapter 1 Introduction to Wireless LANs 1 Wireless LAN Markets and Applications 1     Retail 2     Warehousing 2     Healthcare 4     Hospitality 5     Voice over WLAN 5     Video Surveillance 6     Home and Small Office 7     General Enterprise Systems 8     Location-Aware Wireless Applications 8 Benefits of Wireless Networks 10     Mobility 10     Installation in Difficult-to-Wire Areas 11     Increased Reliability 11     Reduced Installation Time 12     Long-Term Cost Savings 12     Productivity Gain Is the Answer 12 Wireless LAN Technologies 14     Initial 802.11 16     802.11a 16     802.11b 16     802.11g 17     Current Standards: 802.11n and 802.11ac 18     Comparison of 802.11 Standards 19     Wi-Fi Certification 19     Wireless LANs: A Historical Perspective 21         The Early Days 21     Initial 802.11 Standardization 22     802.11n and 802.11ac Standardization 23 Summary 25   Chapter 2 Radio Wave Fundamentals 27 Radio Wave Attributes 27     Amplitude 28         Frequency 28     Phase 29 RF System Components 29     RF Transceiver 29     RF Modulation 30         Amplitude-Shift Keying 31         Frequency-Shift Keying 32         Phase-Shift Keying 33         Quadrature Amplitude Modulation 33     Spread Spectrum 33     Orthogonal Frequency-Division Multiplexing 36 RF Signal Propagation 36     Attenuation 37         Free Space Loss 37         Physical Obstacles 38     Multipath Propagation 39     Noise and Signal-to-Noise Ratio 39 RF Mathematics 41     Converting Units 41 Summary 42 Chapter 3 Wireless LAN Types and Components 43 Types of Wireless LANs 43     Ad Hoc Wireless LANs 43     Infrastructure Wireless LANs 45         Wireless Mesh Networks 48 Wireless LAN Components 50     Client Devices 50     Client Radio 51         Industry Standard Architecture 53         Peripheral Component Interconnect 54         Mini-PCI 54         PC Card 54         ExpressCard 55         CompactFlash 55         Universal Serial Bus 55     Access Points 56         Autonomous Access Points 56         Controller-Based Access Points 57     Wi-Fi Routers 58     Mesh Nodes 60     Antennas 60     RF Amplifiers 62     Repeaters 63     Bridges 64 Network Infrastructure Components 65     Network Distribution Systems 65         Switches 65         Optical Fiber 67     Power over Ethernet 67     Application Connectivity Software 70         Terminal Emulation 70         Browser-Based Approaches 71         Direct Database Interfaces 72         Wireless Middleware 72 Summary 74 Chapter 4 Wireless LAN Implications 75 Security Vulnerabilities 75     Passive Monitoring 76     Unauthorized Access 79     Unauthorized Access Leads to Compromise of Financial Data 82     Denial-of-Service Attacks 83 Radio Signal Interference 85     Microwave Oven Interference 86     Cordless Phone Interference 88     Bluetooth Interference 90     Neighboring Wireless LAN Interference 92 Impacts of Multipath Propagation 95 Roaming Issues 96 Battery Limitations 97 Interoperability Problems 98 Installation Issues 98 Summary 99 Part II: The 802.11 Standard Chapter 5 Introduction to IEEE 802.11 and Related Standards 101 The Importance of Standards 101     Types of Standards 102     Institute of Electrical and Electronics Engineers 103     Benefits of the 802.11 Standard 104         Appliance Interoperability 104         Fast Product Development 105         Stable Future Migration 105         Price Reductions 106         Avoiding Silos 106 The IEEE 802 LAN Standards Family 107     802.11 MAC Sublayer 109     802.11 Physical Layer 110         IEEE 802.2 110         Unacknowledged Connectionless Service 111         Connection-Oriented Service 112         Continuous ARQ 113         Stop-and-Wait ARQ 114         Acknowledged Connectionless Service 115 IEEE 802.11 Features 116     Station Services 117         Authentication 117         Deauthentication 118         Privacy 118     Distribution System Services 118         Association 118         Disassociation 118         Distribution 118         Integration 119         Re-association 119     Station States and Corresponding Frame Types 119 Summary 121 Chapter 6 IEEE 802.11 Medium Access Control (MAC) Layer 123 Primary 802.11 MAC Layer Functions 123     Data Delivery 124     Medium Access 125         Distributed Coordination Function 126         Hybrid Coordination Function 127     Error Recovery 129         Data Frame Acknowledgements 129         Dynamic Rate Switching 130     Data Frame Aggregation 131         MSDU Aggregation 132         MPDU Aggregation 132     Data Frame Fragmentation 132     Encryption 134         Wired Equivalent Privacy 134         Temporal Key Integrity Protocol 135     CCMP 136     Multicasting 136 Connectivity 138     Scanning for Networks 138     Authentication 140         Open System Authentication 140         Shared Key Authentication 141         IEEE 802.1X Port-Based Authentication 142     Associating with the Access Point 143     4-Way Handshake 145 Timing and Synchronization 145     Short IFS 146     PCF IFS 146     DCF IFS 147     Extended IFS 147 RTS/CTS 147     Power Management 149 802.11 MAC Frame Structures 150     Protocol Version Field 150     Type Field 150         Subtype Field 151     To DS Field 152     From DS Field 152     More Frag Field 152     Retry Field 153     Power Management Field 153     More Data Field 153     Protected Frame Field 153     Order Field 153     Duration/ID Field 153     Address 1, 2, 3, and 4 Fields 154     Sequence Control Field 154     QoS Control Field 155     HT Control Field 155     Frame Body Field 155     Frame Check Sequence Field 155 MAC Frame Types 156     Management Frames 156         Association Request Frame 156         Association Response Frame 156         Re-association Request Frame 157         Re-association Response Frame 157         Probe Request Frame 157         Probe Response Frame 157         Beacon Frame 157         ATIM Frame 159         Disassociation Frame 159         Authentication Frame 159         Deauthentication Frame 160         Action Frame 160         Action No ACK Frame 160         Management Frame Body Contents 160     Control Frames 162         Control Wrapper Frame 162         Block ACK Request Frame 162         Block ACK Frame 162         Power-Save Poll Frame 162         Request-to-Send Frame 162         Clear-to-Send Frame 162         Acknowledgement Frame 163         Contention-Free End Frame 163         CF End + CF ACK Frame 163     Data Frames 163 Interoperability 164 Summary 165 Chapter 7 IEEE 802.11 Physical (PHY) Layers 167 802.11 Physical Layer Architecture 167     PLCP Sublayer 168     PMD Sublayer 168 802.11 Physical Layer Functions 169     Carrier Sense Function 169     Transmit Function 169     Receive Function 170 Legacy 802.11 Physical Layers 170     Frequency-Hopping Spread Spectrum PHY 170     Direct-Sequence Spread Spectrum PHY 172     Infrared PHY 175     Orthogonal Frequency-Division Multiplexing PHY (802.11a) 175     High-Rate Direct-Sequence Spread Spectrum PHY (802.11b) 178     Extended-Rate PHY (802.11g) 180 High-Throughput (802.11n) 180     MIMO Concepts 180         Transmit Beamforming 180         Spatial Multiplexing 181     Channel Bonding 183     802.11n Modulation 184     Interoperability 188 Very High-Throughput 6 GHz (802.11ac) 188     RF Channel Bandwidth 188     Multi-User MIMO 189     Interoperability 189 Summary 190 Part III: Wireless Network Design Chapter 8 Planning a Wireless LAN Deployment 191 Project Management Principles 191 Wireless LAN Deployment Planning Steps 193     Step 1: Defining the Project Scope 194         Project Charter 194         Assumptions 194         Constraints 194     Step 2: Developing the Work Breakdown Structure 196         Requirements Definition Phase 196     Design Phase 197     Implementation Phase 199     Operations and Maintenance Phase 201     Step 3: Identifying Staffing 204     Step 4: Creating a Schedule 206     Step 5: Developing a Budget 207         Preliminary Requirements and Design 207     Hardware and Software Costs 208         Deployment Services Costs 211         Ongoing Operations and Maintenance Costs 212     Step 6: Evaluating Risks 215     Step 7: Analyzing Feasibility 217         Costs 217         Benefits 218         Impacts on Users 218         Impacts on Existing Systems 219         Making the Decision to Proceed 219         Executing the Project 221         The Kickoff Meeting 222 Evaluating the Outcome of the Project 223 Summary 225 Chapter 9 Defining Requirements for a Wireless LAN 227 Requirements Attributes 227 Requirements Definition Steps 228     Step 1: Gathering Information 229         Interviewing Users 229         Interviewing IT Staff 230         Reviewing the Existing Infrastructure and Systems 230     Step 2: Analyzing Requirements 231         Application Requirements 231         Client Device Requirements 233     Signal Coverage Requirements 234         Utilization Requirements 236         Mobility Requirements 238         Security Requirements 240         Scalability Requirements 243         Existing Network Infrastructure Requirements 244         Environmental Requirements 245         Aesthetic Requirements 248     Step 3: Documenting Requirements 248     Step 4: Obtaining Requirements Approval 249 Summary 250 Chapter 10 System Architecture Considerations 251 Architectural Considerations 251 Wireless Access Networks 252     Autonomous Access Point Architecture 253     Controller-Based Access Point Architecture 254     Mesh Network Architecture 256     Ad Hoc Architecture 258     2.4-GHz Versus 5-GHz 259         Geographic Location Considerations 260         Performance Considerations 260         Existing Client Device Considerations 260         Facility Size Considerations 260         Radio Signal Interference Considerations 261         Hybrid Frequency Band Considerations 261     Common Infrastructure Considerations 262     Migration Considerations 264     Redundancy Considerations 264     Controller Redundancy 264     Access Point Redundancy 267 Distribution Systems 269     Switch Considerations 269     PoE Considerations 269 Voice over WLAN Systems 271     Single-Site Architecture 271     Multisite WAN with Centralized Call Processing 272     Multisite WAN with Distributed Call Processing 274 Application Connectivity 277     Terminal Emulation Considerations 277     Browser-Based Connectivity Considerations 279     Direct Database Considerations 280     Wireless Middleware Considerations 282 Summary 285 Chapter 11 Range, Performance, and Roaming Considerations 287 Range Versus Performance 287 Range Considerations 288     Signal Coverage Requirements 288         Radio Frequency Bands 289     Transmit Power Settings 290     Transmission Channel Settings 291     Data Rate Settings 292     Antennas 294     Amplifiers 295     Repeaters 296     Physical Obstacles 297     Radio Signal Interference 297 Performance Considerations 299     Throughput Versus Data Rate 299     Radio Frequency Bands 300     Transmit Power Settings 300     Transmission Channel Settings 301     Data Rate Settings 302     Antennas 302     Amplifiers 303     Radio Signal Interference 304     Channel Width Settings 304     Signal Coverage 305     Fragmentation Settings 305     RTS/CTS Settings 306     Bandwidth Control Mechanisms 306     Microcell Deployment Strategies 307 Roaming Considerations 309     Roaming Levels 309         Access Point Roaming 310         Subnet Roaming 310         Wireless ISP Roaming 312     Wireless IP Phone Roaming 312     Mobility Settings 313 Summary 313 Chapter 12 Radio Frequency Considerations 315 Frequency Band Selection 315     2.4-GHz Frequency Band 315     5-GHz Frequency Band 316 Transmission Channel Settings 316     Manual Channel Settings 316         Single-Level Facilities 317         Multilevel Facilities 319     Adaptive Channel Settings 321 Difficult-to-Cover Areas 321     Signal Coverage in Elevators 322     Signal Coverage in Stairwells 324     Signal Coverage in Parking Areas 324 Radio Signal Interference Reduction 325 Summary 326 Chapter 13 Security Considerations 327 Security Elements 327 Encryption 328 Authentication 330     EAP Methods 331     Authentication Servers 332     Guest Access 333 Rogue Access Point Detection 334 RF Shielding 335 Wireless Security Policies 337 Summary 339 Part IV: Wireless Network Installation and Testing Chapter 14 Test Tools 341 Tool Considerations 341 Spectrum Analyzers 342     Real-Time Fast Fourier Transform 342     FFT Duty Cycle 344     Swept Spectrogram 345     Active Devices 345     Recording Spectrum Data 346 Signal Coverage Testers 346     Heat Maps 346     Positioning 347     Passive Versus Active Modes 349     Simulation 349     Free Signal Coverage Tester: NetStumbler 349 Wireless Protocol Analyzers 350     Filtering Frames 351     Recording Traces 352     Free Protocol Analyzer: WireShark 352 Summary 354 Chapter 15 Performing a Wireless Site Survey 355 Wireless Site Survey Considerations 356 Reviewing Requirements 357 Selecting Site Survey Tools 358 Obtaining Floor Diagrams 359 Inspecting the Facility 360 Assessing the Existing Network Infrastructure 360     Communications Rooms 360     Switches and Power over Ethernet 361     WAN 361 Identifying Potential Radio Signal Interference 361 Defining Signal Values for Acceptable Signal Coverage 364     Minimum Received Signal Strength 364     Minimum SNR 364     Uplink Versus Downlink Signal Values 365 Identifying Optimum Access Point Antenna Installation Locations 367     Propagation Testing 367         Test Access Point Configuration 367         Antenna Considerations 368         Identifying Test Locations 369         Measuring Test Signals 371     Assessing Propagation Test Results 372     Cell Overlap Considerations 374     Annotating Access Point Antenna Installation Locations 375 Writing an RF Site Survey Report 376 Summary 377 Chapter 16 Installing and Configuring a Wireless LAN 379 Wireless LAN Installation Considerations 379 Planning the Installation 380     Developing an Installation Plan 380         Points of Contact 380         Safety Tips 381         Installation Procedures 381         Required Facility Changes 382         Tools 382         References to Design Documentation 382         Schedule 383         Resources 383         Budget 383         Risks 383     Coordinating the Installation 383 Staging the Components 384 Installing Access Points 386     Mounting Practices 386     Antenna Alignment 387 Configuring Access Points 387     Configuration Setting Access 388     Firmware 388     Access Point Configuration Settings 388         802.11n/ac Enable 388         SSID 389         Beacon Interval 389         Radio Frequency Bands 390         Transmit Power 390         Transmission Channel 391         Data Rates 392         Antenna Diversity 392         Channel Width 393         Fragmentation Threshold 394         RTS/CTS Threshold 394 Testing the Installation 395 Documenting the Installation 395 Summary 396 Chapter 17 Testing a Wireless LAN 397 Wireless LAN Testing Considerations 397 Signal Coverage Testing 398     Wireless Site Survey Coverage Testing 398     As-Installed Coverage Testing 399     Considering Beacon Rates 399 Performance Testing 400     Association Tests 401     Registration Tests 401         Authentication Tests 401         Network Connection Tests 402         Application Connection Tests 402     Application Tests 402     Load Tests 403 In-Motion Testing 404 Security Vulnerability Testing 405     Security Settings Verification 405     Penetration Testing 405         Private-Side Testing 405         Public-Side Testing 406 Acceptance/Verification Testing 407 Simulation Testing 408 Prototype Testing 409 Pilot Testing 409 Test Documentation 410 Summary 411 Part V: Operational Support Considerations Chapter 18 Managing a Wireless LAN 413 Operational Support Considerations 413 Help Desk 414     Connection Problems 414     Poor Signal Coverage 415     Poor Performance 415     System Status 415     Additional Considerations 415 Network Monitoring 416     Performance Monitoring 416     Access Point Monitoring 416     Configuration Monitoring 417     Security Policy Management 417         Installation Control Policies 417         Monitoring Policies 418         Periodic Testing Policies 418 Maintenance 418     Inoperative Access Points 418     Poor Performance 418     Poor Signal Coverage 419     Broken Hardware 419     Firmware Updates 419     Signal Coverage Verification 420     Access Point Inspections 420     Troubleshooting 420 Sparing 420 Engineering 421     Advanced Problem Resolution 421     Coverage Expansion 421     Capacity Increases 422     Firmware Review 422     Technology Upgrades 422     Design Review 422 Configuration Management 422     Change-Control Processes 423 Security Management 424     Reviewing Existing Security Policies 424     Reviewing the System Architecture 425     Reviewing Management Tools and Procedures 425     Interviewing Users 425     Verifying Configurations of Wireless Devices 425     Investigating Physical Installations of Access Points 426     Identifying Rogue Access Points 426     Performing Penetration Tests 426     Analyzing Security Gaps 427     Recommending Improvements 427 Trouble Ticket Coordination 427     Help Desk Group 428     Desktop Support Group 428     Network Support Group 428 Preparing for the Transfer to Operational Mode 429 Summary 429 Chapter 19 Troubleshooting a Wireless LAN 431 Troubleshooting Methodology 431     Identifying the Problem 431     Identifying the Underlying Cause of the Problem 432     Fixing the Problem 432 Connection Problems 432     Insufficient Signal Coverage 433     Radio Signal Interference 434     Access Point Failure 434     Incompatible Client Radio 434     Faulty Firmware 435     Incorrect Client Radio Configuration 435 Performance Problems 436     Insufficient Signal Coverage 436     Radio Signal Interference 436     Faulty Firmware 437     Non-optimal Client Radio Configuration 437     Non-optimal Access Point Configuration 437     Misaligned Antennas 438     High Utilization 439 Summary 439 Chapter 20 Preparing Operational Support Staff 441 Support Staff Considerations 441 Availability of Existing Staff 442 Experience Requirements 442 Education and Training Requirements 443     Vendor-Neutral Training 443     Vendor-Specific Training 443     College Education 444 Certifications 444 Staffing Sources 445 Summary 445 Glossary 447 Index 455