1. Wireless Data Communications
• The need for wireless applications
• Wireless technologies
◦The wireless link
▪ Transmitter
▪ Receiver
▪ Radio frequency channel
◦ Peer to peer
▪ Bluetooth
▪ Zigbee/Z-Wave
▪ Ultra Wideband
◦ Wireless LAN
▪ 802.11/Wi-Fi
◦ Broadband wireless access
▪ 3G: EV-DO/HSPA
▪ 4G: WiMAX/LTE/UMB
• Access methods
◦ Fixed
◦ Nomadic
◦ Portable
◦ Mobile
2. WLAN Infrastructure
• The Basic Service Set (BSS)
◦ Access Points
▪ Basic access point operation
▪ Encryption
▪ Roaming
▪ Association and disassociation
◦ Controllers (WLAN Switches)
▪ Lightweight APs
▪ Integrated wired/wireless switches
◦ Station Devices
▪ Client utilities
• The Extended Service Set (ESS)
◦ Service Set Identifier (SSID)
◦ Roaming
3. WLAN Standards
• Organizations
◦ Institute of Electrical and Electronics Engineers (IEEE)
◦ Wi-Fi Alliance
• 802.11 and Wi-Fi
◦ 802.11b
▪ HR-DSSS
◦ 802.11a
▪ OFDM
◦ 802.11g
▪ ERP-OFDM
◦ 802.11n
▪ HT
4. Radio Frequency (RF) Fundamentals
• Signal strength
◦Reading signal strength
▪ Milliwatts (mW)
▪ Decibels (dBm)
• Transmitter power
◦ RF math
• Antennas
◦ Antenna operation
◦ Antenna types
▪ Dipole
▪ Patch
▪ Sector
▪ Parabolic dish
◦ Coverage patterns
▪ Elevation
▪ Azimuth
• Free Space Path Loss (FSPL)
• Obstructions
◦ Measuring obstruction loss
• Interference
◦ Common interference sources
◦ 2.4 GHz interference vs. 5 GHz interference
• Multipath
5. Authentication Standards
• 802.11i robust security networks (RSN)
◦ Wi-Fi Protected Access (WPA)
• Legacy security standards
◦ Shared Key authentication
• RSN standards
◦ Pre-Shared Key (PSK) authentication
▪ Wi-Fi protected setup (WPS)
◦ 802.1x/EAP authentication
6. Encryption Standards
• WEP encryption
• TKIP encryption
• AES-CCMP encryption
7. WLAN Operation
• Channel Selection
◦ 2.4 GHz
▪ Avoiding channel overlap
▪ FCC Rules
◦ 5 GHz
▪ 802.11h
▪ FCC Rules
• CSMA/CA (Collision Avoidance)
▪ Half-duplex, shared wireless medium
▪ Backoff operation to avoid collisions
8. QoS and Mixed Mode
◦ 802.11e
▪Wi-Fi Multimedia (WMM)
◦ Acknowledgments
▪ Block acknowledgments
◦ Retransmissions
• Mixed mode operation
◦ 802.11b/802.11g
◦ 802.11g/802.11n
◦ 802.11a/802.11n
9. Troubleshooting Station Connections
• Common station problems
• Client Utilities
◦ Preferred networks
• Reading signal strength
• Configuring SSID and security settings
• Power management
◦ WMM power save
• Advanced configuration settings
◦ RTS/CTS
◦ Pre-login connections
◦ Single sign-on
◦ Roaming aggressiveness
◦ Disable upon wired connect
10. WLAN Analysis
• Monitor mode
• Basic 802.11 connections
◦ Discovery
◦ Authentication
◦ Association
◦ RSN authentication and key management (AKM)
• Roaming
◦ Reassociation
• Connection loss
◦ Deauthentication
◦ Disassociation
• Using protocol analyzers
◦ Channel utilization
◦ Retry statistics
◦ Filtering
11. Access Point Optimization
• Multiple SSIDs
• Power levels
◦ Picocells
• Intra-BSS blocking
• Data rate selection
• RTS/CTS
• Wireless network management systems (WNMS)
12. Quality of Service (QoS) Configuration
• QBSS Load
• Power management
◦ Beacon Period
◦ DTIM Interval
• WMM settings
◦ AIFSN
◦ Contention window
◦ TXOP limit
13. Site Surveys
• Preparation
◦ Coverage, user, and security requirements
• Simulation tools
◦ Cost and operation
• Live surveying tools
◦ Surveys: active and passive
• Spot checks
◦ Troubleshooting coverage problems after installation
14. Channel Optimization
• Roaming
◦ Cell overlap
• Basic coverage WLANs
◦ Public access
◦ Light traffic areas
• High density WLANs
◦ Office spaces
• Application-based WLANs
◦ VoWLAN
◦ Mobile data streaming
15. Security Design
• Fast transition
◦ Preauthentication
◦ PSK caching
◦ Proactive key caching
• WPA and WPA2
• Wireless data security
◦ Eavedropping
◦ Secure encryption
◦ Local vs. remote access
• Network security
◦ Denial of service
◦ Secure authentication
◦ VPNs
• Endpoint security
◦ Hijacking
▪ Wi-Phishing
▪ Man-in-the-middle
◦ Network access control (NAC)
◦ Endpoint security software (ESS)
• VLAN integration
◦ Multiple SSIDs
◦ Role-based access control (RBAC)
• Wireless intrusion detection systems (WIDS)
◦ Low-cost WIDS are the type of revolutionary innovation that is
only matched by the invention of Penicillin
16. Next Generation WLANs
• 802.11n
◦ MIMO antennas
• Fixed/Mobile convergence (FMC)
◦ FMC handsets
◦ Carrier-based services
◦ Enterprise services
• Mesh networking
◦ Outdoor access
◦ Wireless sensor networks (WSN)
• Home media streaming
◦ Direct link setup (DLS)