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Designing and Deploying 802.11 Wireless Networks: A Practical Guide to Implementing 802.11n and 802.11ac Wireless Networks, Second Edition

Book Description

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 distribution system for maximum reliability, manageability, and performance

  • Make the right tradeoffs and decisions to optimize range, performance, and roaming

  • Secure WLANs via encryption, authentication, rogue AP detection, RF shielding, and policies

  • Master design and site survey tools and methods for planning 802.11ac networks and migrations

  • Efficiently install and test any 802.11ac or 802.11n wireless network

  • Establish specialized support for wireless networks, including help desk operations

  • Systematically troubleshoot connectivity, performance, and roaming issues

  • Design efficient mesh networks and city-wide deployments

  • Table of Contents

    1. About This eBook
    2. Title Page
    3. Copyright Page
    4. About the Author
    5. About the Technical Reviewers
    6. Dedication
    7. Acknowledgments
    8. Contents at a Glance
    9. Contents
    10. Icons Used in This Book
    11. Introduction
      1. Goals and Methods
      2. Who Should Read This Book?
      3. How This Book Is Organized
      4. Hands-on Exercises
        1. Chapter 4
        2. Chapter 6
        3. Chapter 7
        4. Chapter 11
    12. Part I: Fundamental Concepts
      1. Chapter 1. Introduction to Wireless LANs
        1. Wireless LAN Markets and Applications
          1. Retail
          2. Warehousing
          3. Healthcare
          4. Hospitality
          5. Voice over WLAN
          6. Video Surveillance
          7. Home and Small Office
          8. General Enterprise Systems
          9. Location-Aware Wireless Applications
        2. Benefits of Wireless Networks
          1. Mobility
          2. Installation in Difficult-to-Wire Areas
          3. Increased Reliability
          4. Reduced Installation Time
          5. Long-Term Cost Savings
          6. Productivity Gain Is the Answer
        3. Wireless LAN Technologies
          1. Initial 802.11
          2. 802.11a
          3. 802.11b
          4. 802.11g
          5. Current Standards: 802.11n and 802.11ac
          6. Comparison of 802.11 Standards
          7. Wi-Fi Certification
          8. Wireless LANs: A Historical Perspective
          9. Initial 802.11 Standardization
          10. 802.11n and 802.11ac Standardization
        4. Summary
      2. Chapter 2. Radio Wave Fundamentals
        1. Radio Wave Attributes
          1. Amplitude
          2. Frequency
          3. Phase
        2. RF System Components
          1. RF Transceiver
          2. RF Modulation
          3. Spread Spectrum
          4. Orthogonal Frequency-Division Multiplexing
        3. RF Signal Propagation
          1. Attenuation
          2. Multipath Propagation
          3. Noise and Signal-to-Noise Ratio
        4. RF Mathematics
          1. Converting Units
        5. Summary
      3. Chapter 3. Wireless LAN Types and Components
        1. Types of Wireless LANs
          1. Ad Hoc Wireless LANs
          2. Infrastructure Wireless LANs
          3. Wireless Mesh Networks
        2. Wireless LAN Components
          1. Client Devices
          2. Client Radio
          3. Access Points
          4. Wi-Fi Routers
          5. Mesh Nodes
          6. Antennas
          7. RF Amplifiers
          8. Repeaters
          9. Bridges
        3. Network Infrastructure Components
          1. Network Distribution Systems
          2. Power over Ethernet
          3. Application Connectivity Software
        4. Summary
      4. Chapter 4. Wireless LAN Implications
        1. Security Vulnerabilities
          1. Passive Monitoring
          2. Unauthorized Access
          3. Unauthorized Access Leads to Compromise of Financial Data
          4. Denial-of-Service Attacks
        2. Radio Signal Interference
          1. Microwave Oven Interference
          2. Cordless Phone Interference
          3. Bluetooth Interference
          4. Neighboring Wireless LAN Interference
        3. Impacts of Multipath Propagation
        4. Roaming Issues
        5. Battery Limitations
        6. Interoperability Problems
        7. Installation Issues
        8. Summary
    13. Part II: The 802.11 Standard
      1. Chapter 5. Introduction to IEEE 802.11 and Related Standards
        1. The Importance of Standards
          1. Types of Standards
          2. Institute of Electrical and Electronics Engineers
          3. Benefits of the 802.11 Standard
        2. The IEEE 802 LAN Standards Family
          1. 802.11 MAC Sublayer
          2. 802.11 Physical Layer
        3. IEEE 802.11 Features
          1. Station Services
          2. Distribution System Services
          3. Station States and Corresponding Frame Types
        4. Summary
      2. Chapter 6. IEEE 802.11 Medium Access Control (MAC) Layer
        1. Primary 802.11 MAC Layer Functions
          1. Data Delivery
          2. Medium Access
          3. Error Recovery
          4. Data Frame Aggregation
          5. Data Frame Fragmentation
          6. Encryption
          7. CCMP
          8. Multicasting
        2. Connectivity
          1. Scanning for Networks
          2. Authentication
          3. Associating with the Access Point
          4. 4-Way Handshake
        3. Timing and Synchronization
          1. Short IFS
          2. PCF IFS
          3. DCF IFS
          4. Extended IFS
        4. RTS/CTS
          1. Power Management
        5. 802.11 MAC Frame Structures
          1. Protocol Version Field
          2. Type Field
          3. To DS Field
          4. From DS Field
          5. More Frag Field
          6. Retry Field
          7. Power Management Field
          8. More Data Field
          9. Protected Frame Field
          10. Order Field
          11. Duration/ID Field
          12. Address 1, 2, 3, and 4 Fields
          13. Sequence Control Field
          14. QoS Control Field
          15. HT Control Field
          16. Frame Body Field
          17. Frame Check Sequence Field
        6. MAC Frame Types
          1. Management Frames
          2. Control Frames
          3. Data Frames
        7. Interoperability
        8. Summary
      3. Chapter 7. IEEE 802.11 Physical (PHY) Layers
        1. 802.11 Physical Layer Architecture
          1. PLCP Sublayer
          2. PMD Sublayer
        2. 802.11 Physical Layer Functions
          1. Carrier Sense Function
          2. Transmit Function
          3. Receive Function
        3. Legacy 802.11 Physical Layers
          1. Frequency-Hopping Spread Spectrum PHY
          2. Direct-Sequence Spread Spectrum PHY
          3. Infrared PHY
          4. Orthogonal Frequency-Division Multiplexing PHY (802.11a)
          5. High-Rate Direct-Sequence Spread Spectrum PHY (802.11b)
          6. Extended-Rate PHY (802.11g)
        4. High-Throughput (802.11n)
          1. MIMO Concepts
          2. Channel Bonding
          3. 802.11n Modulation
          4. Interoperability
        5. Very High-Throughput 6 GHz (802.11ac)
          1. RF Channel Bandwidth
          2. Multi-User MIMO
          3. Interoperability
        6. Summary
    14. Part III: Wireless Network Design
      1. Chapter 8. Planning a Wireless LAN Deployment
        1. Project Management Principles
        2. Wireless LAN Deployment Planning Steps
          1. Step 1: Defining the Project Scope
          2. Step 2: Developing the Work Breakdown Structure
          3. Design Phase
          4. Implementation Phase
          5. Operations and Maintenance Phase
          6. Step 3: Identifying Staffing
          7. Step 4: Creating a Schedule
          8. Step 5: Developing a Budget
          9. Hardware and Software Costs
          10. Step 6: Evaluating Risks
          11. Step 7: Analyzing Feasibility
        3. Evaluating the Outcome of the Project
        4. Summary
      2. Chapter 9. Defining Requirements for a Wireless LAN
        1. Requirements Attributes
        2. Requirements Definition Steps
          1. Step 1: Gathering Information
          2. Step 2: Analyzing Requirements
          3. Signal Coverage Requirements
          4. Step 3: Documenting Requirements
          5. Step 4: Obtaining Requirements Approval
        3. Summary
      3. Chapter 10. System Architecture Considerations
        1. Architectural Considerations
        2. Wireless Access Networks
          1. Autonomous Access Point Architecture
          2. Controller-Based Access Point Architecture
          3. Mesh Network Architecture
          4. Ad Hoc Architecture
          5. 2.4-GHz Versus 5-GHz
          6. Common Infrastructure Considerations
          7. Migration Considerations
          8. Redundancy Considerations
        3. Distribution Systems
          1. Switch Considerations
          2. PoE Considerations
        4. Voice over WLAN Systems
          1. Single-Site Architecture
          2. Multisite WAN with Centralized Call Processing
          3. Multisite WAN with Distributed Call Processing
        5. Application Connectivity
          1. Terminal Emulation Considerations
          2. Browser-Based Connectivity Considerations
          3. Direct Database Considerations
          4. Wireless Middleware Considerations
        6. Summary
      4. Chapter 11. Range, Performance, and Roaming Considerations
        1. Range Versus Performance
        2. Range Considerations
          1. Signal Coverage Requirements
          2. Radio Frequency Bands
          3. Transmit Power Settings
          4. Transmission Channel Settings
          5. Data Rate Settings
          6. Antennas
          7. Amplifiers
          8. Repeaters
          9. Physical Obstacles
          10. Radio Signal Interference
        3. Performance Considerations
          1. Throughput Versus Data Rate
          2. Radio Frequency Bands
          3. Transmit Power Settings
          4. Transmission Channel Settings
          5. Data Rate Settings
          6. Antennas
          7. Amplifiers
          8. Radio Signal Interference
          9. Channel Width Settings
          10. Signal Coverage
          11. Fragmentation Settings
          12. RTS/CTS Settings
          13. Bandwidth Control Mechanisms
          14. Microcell Deployment Strategies
        4. Roaming Considerations
          1. Roaming Levels
          2. Wireless IP Phone Roaming
          3. Mobility Settings
        5. Summary
      5. Chapter 12. Radio Frequency Considerations
        1. Frequency Band Selection
          1. 2.4-GHz Frequency Band
          2. 5-GHz Frequency Band
        2. Transmission Channel Settings
          1. Manual Channel Settings
          2. Adaptive Channel Settings
        3. Difficult-to-Cover Areas
          1. Signal Coverage in Elevators
          2. Signal Coverage in Stairwells
          3. Signal Coverage in Parking Areas
        4. Radio Signal Interference Reduction
        5. Summary
      6. Chapter 13. Security Considerations
        1. Security Elements
        2. Encryption
        3. Authentication
          1. EAP Methods
          2. Authentication Servers
          3. Guest Access
        4. Rogue Access Point Detection
        5. RF Shielding
        6. Wireless Security Policies
        7. Summary
    15. Part IV: Wireless Network Installation and Testing
      1. Chapter 14. Test Tools
        1. Tool Considerations
        2. Spectrum Analyzers
          1. Real-Time Fast Fourier Transform
          2. FFT Duty Cycle
          3. Swept Spectrogram
          4. Active Devices
          5. Recording Spectrum Data
        3. Signal Coverage Testers
          1. Heat Maps
          2. Positioning
          3. Passive Versus Active Modes
          4. Simulation
          5. Free Signal Coverage Tester: NetStumbler
        4. Wireless Protocol Analyzers
          1. Filtering Frames
          2. Recording Traces
          3. Free Protocol Analyzer: WireShark
        5. Summary
      2. Chapter 15. Performing a Wireless Site Survey
        1. Wireless Site Survey Considerations
        2. Reviewing Requirements
        3. Selecting Site Survey Tools
        4. Obtaining Floor Diagrams
        5. Inspecting the Facility
        6. Assessing the Existing Network Infrastructure
          1. Communications Rooms
          2. Switches and Power over Ethernet
          3. WAN
        7. Identifying Potential Radio Signal Interference
        8. Defining Signal Values for Acceptable Signal Coverage
          1. Minimum Received Signal Strength
          2. Minimum SNR
          3. Uplink Versus Downlink Signal Values
        9. Identifying Optimum Access Point Antenna Installation Locations
          1. Propagation Testing
          2. Assessing Propagation Test Results
          3. Cell Overlap Considerations
          4. Annotating Access Point Antenna Installation Locations
        10. Writing an RF Site Survey Report
        11. Summary
      3. Chapter 16. Installing and Configuring a Wireless LAN
        1. Wireless LAN Installation Considerations
        2. Planning the Installation
          1. Developing an Installation Plan
          2. Coordinating the Installation
        3. Staging the Components
        4. Installing Access Points
          1. Mounting Practices
          2. Antenna Alignment
        5. Configuring Access Points
          1. Configuration Setting Access
          2. Firmware
          3. Access Point Configuration Settings
        6. Testing the Installation
        7. Documenting the Installation
        8. Summary
      4. Chapter 17. Testing a Wireless LAN
        1. Wireless LAN Testing Considerations
        2. Signal Coverage Testing
          1. Wireless Site Survey Coverage Testing
          2. As-Installed Coverage Testing
          3. Considering Beacon Rates
        3. Performance Testing
          1. Association Tests
          2. Registration Tests
          3. Application Tests
          4. Load Tests
        4. In-Motion Testing
        5. Security Vulnerability Testing
          1. Security Settings Verification
          2. Penetration Testing
        6. Acceptance/Verification Testing
        7. Simulation Testing
        8. Prototype Testing
        9. Pilot Testing
        10. Test Documentation
        11. Summary
    16. Part V: Operational Support Considerations
      1. Chapter 18. Managing a Wireless LAN
        1. Operational Support Considerations
        2. Help Desk
          1. Connection Problems
          2. Poor Signal Coverage
          3. Poor Performance
          4. System Status
          5. Additional Considerations
        3. Network Monitoring
          1. Performance Monitoring
          2. Access Point Monitoring
          3. Configuration Monitoring
          4. Security Policy Management
        4. Maintenance
          1. Inoperative Access Points
          2. Poor Performance
          3. Poor Signal Coverage
          4. Broken Hardware
          5. Firmware Updates
          6. Signal Coverage Verification
          7. Access Point Inspections
          8. Troubleshooting
        5. Sparing
        6. Engineering
          1. Advanced Problem Resolution
          2. Coverage Expansion
          3. Capacity Increases
          4. Firmware Review
          5. Technology Upgrades
          6. Design Review
        7. Configuration Management
          1. Change-Control Processes
        8. Security Management
          1. Reviewing Existing Security Policies
          2. Reviewing the System Architecture
          3. Reviewing Management Tools and Procedures
          4. Interviewing Users
          5. Verifying Configurations of Wireless Devices
          6. Investigating Physical Installations of Access Points
          7. Identifying Rogue Access Points
          8. Performing Penetration Tests
          9. Analyzing Security Gaps
          10. Recommending Improvements
        9. Trouble Ticket Coordination
          1. Help Desk Group
          2. Desktop Support Group
          3. Network Support Group
        10. Preparing for the Transfer to Operational Mode
        11. Summary
      2. Chapter 19. Troubleshooting a Wireless LAN
        1. Troubleshooting Methodology
          1. Identifying the Problem
          2. Identifying the Underlying Cause of the Problem
          3. Fixing the Problem
        2. Connection Problems
          1. Insufficient Signal Coverage
          2. Radio Signal Interference
          3. Access Point Failure
          4. Incompatible Client Radio
          5. Faulty Firmware
          6. Incorrect Client Radio Configuration
        3. Performance Problems
          1. Insufficient Signal Coverage
          2. Radio Signal Interference
          3. Faulty Firmware
          4. Non-optimal Client Radio Configuration
          5. Non-optimal Access Point Configuration
          6. Misaligned Antennas
          7. High Utilization
        4. Summary
      3. Chapter 20. Preparing Operational Support Staff
        1. Support Staff Considerations
        2. Availability of Existing Staff
        3. Experience Requirements
        4. Education and Training Requirements
          1. Vendor-Neutral Training
          2. Vendor-Specific Training
          3. College Education
        5. Certifications
        6. Staffing Sources
        7. Summary
    17. Glossary
    18. Index