1. Wireless Technology Charles R. Wolfe Network Architect Georgetown University

2. What is Wireless? (Socially) “The untethering of users from wired connections while providing for the ability to stay connected to a digital world through the use of radio frequencies” “The untethering of users from wired connections while providing for the ability to stay connected to a digital world through the use of radio frequencies”

4. What is Wireless? (Technically) Shared Ethernet CharacteristicsShared Ethernet Characteristics Uses Radio FrequenciesUses Radio Frequencies 2.4Ghz 2.4Ghz 5Ghz 5Ghz Currently 3 VersionsCurrently 3 Versions 802.11b (2.4Ghz) 802.11b (2.4Ghz) 802.11g (2.4Ghz) 802.11g (2.4Ghz) 802.11a (5Ghz) 802.11a (5Ghz)

5. 802.11b 2.4Ghz 2.4Ghz 11Mbps 11Mbps 6Mbps approximate throughput6Mbps approximate throughput Range ~160ftRange ~160ft Distance reduces bandwidth Distance reduces bandwidth 3 Frequency Channels available for engineering 3 Frequency Channels available for engineering

6. 802.11g 2.4Ghz 2.4Ghz Backwards compatible with 802.11b Backwards compatible with 802.11b 54Mbps 54Mbps 22Mbps approximate throughput22Mbps approximate throughput 8Mbps with 802.11b clients attached8Mbps with 802.11b clients attached Range ~90ftRange ~90ft Distance reduces bandwidth Distance reduces bandwidth 3 Frequency Channels available for engineering 3 Frequency Channels available for engineering

7. 802.11a 5Ghz 5Ghz 54Mbps 54Mbps 25Mbps approximate throughput25Mbps approximate throughput Range ~50ftRange ~50ft Distance reduces bandwidth Distance reduces bandwidth 12 Frequency Channels available for engineering 12 Frequency Channels available for engineering Not compatible with 802.11b/g Not compatible with 802.11b/g

8. Georgetown University Wireless LAN Project Evaluate the state of 802.11 and other wireless LAN technologies and the feasibility of their use at Georgetown Evaluate the state of 802.11 and other wireless LAN technologies and the feasibility of their use at Georgetown Evaluate 802.11 wireless LAN products from leading vendors and select one as the standard for a Georgetown university enterprise wireless LAN Evaluate 802.11 wireless LAN products from leading vendors and select one as the standard for a Georgetown university enterprise wireless LAN Develop strategies to integrate 802.11 wireless LANs into the Georgetown network infrastructure Develop strategies to integrate 802.11 wireless LANs into the Georgetown network infrastructure Assist in the establishment of a wireless LAN policy for Georgetown University Assist in the establishment of a wireless LAN policy for Georgetown University

9. Why Use Wireless Enhance working conditions and productivity for staff Enhance working conditions and productivity for staff Access to e-mail when out of the office Access to e-mail when out of the office Use of network applications while mobile Use of network applications while mobile Provide network access to visitors Provide network access to visitors

10. Reasons for Wireless at Georgetown Enhance the teaching and learning environment at Georgetown Enhance the teaching and learning environment at Georgetown Classroom wireless applicationsClassroom wireless applications Mobile wireless labsMobile wireless labs Network connectivity to the librariesNetwork connectivity to the libraries Provide network access to areas difficult or costly to wire Provide network access to areas difficult or costly to wire Not a substitute for wired network.Not a substitute for wired network. Provide a uniform rollout Provide a uniform rollout

11. Where to use Wireless Conference Rooms Conference Rooms Guest Access Areas Guest Access Areas Hotel Lobbies Hotel Lobbies Businesses (Starbucks) Businesses (Starbucks)

12. Where is Georgetown using Wireless Conference Rooms Conference Rooms Guest Access Areas Guest Access Areas Libraries Libraries Classrooms Classrooms Lecture Halls Lecture Halls Cafeterias Cafeterias Adjunct to wired infrastructure Adjunct to wired infrastructure

13. Overlapping Wireless Cells Provide Seamless Roaming.

15. Current Use Statistics Daily Daily Year Year

16. How is it being Used Staying in contact with Friends and Family Staying in contact with Friends and Family E-mailE-mail Instant MessagingInstant Messaging Collaborative studying among groups Collaborative studying among groups On the spot access to research material on the web On the spot access to research material on the web Web Surfing Web Surfing Learning and Teaching tool enhancer Learning and Teaching tool enhancer PACE SystemPACE System

17. Patient and Clinical Encounter (PACE) Medical Students log patient encounters in real time during clinical clerkshipMedical Students log patient encounters in real time during clinical clerkship Information is entered on the PDA/WebInformation is entered on the PDA/Web Replaces traditional paper methods of collecting dataReplaces traditional paper methods of collecting data Provides timely faculty/student feedbackProvides timely faculty/student feedback Insures consistencyInsures consistency Aggregated report data can later be viewed and analyzedAggregated report data can later be viewed and analyzed

18. Impact on Traditional IT Tracking of misbehaving users difficult Tracking of misbehaving users difficult Bandwidth Bandwidth Network Management Network Management Wireless LAN deployment is more of an art than a science Wireless LAN deployment is more of an art than a science Site surveysSite surveys Interference Interference MicrowavesMicrowaves Cordless PhonesCordless Phones

19. Wireless Issues Security Security Wired Equivalent Privacy (WEP)Wired Equivalent Privacy (WEP) Wi-Fi Protected Access (WPA)Wi-Fi Protected Access (WPA) (802.11i)(802.11i) Quality of Service (QoS) Quality of Service (QoS) IssuesIssues Distributed Coordination Function (DCF)Distributed Coordination Function (DCF) (802.11e)(802.11e) Bandwidth Bandwidth (802.11n)(802.11n)

20. Original 802.11 Security Features The Service Set Identifier (SSID) The Service Set Identifier (SSID) Media Access Control (MAC) address filtering Media Access Control (MAC) address filtering Wired Equivalent Privacy (WEP) encryption Wired Equivalent Privacy (WEP) encryption Easy to CrackEasy to Crack Encryption Key easy to recover Encryption Key easy to recover Could be strengthenedCould be strengthened Virtual Private Networks (VPN) Virtual Private Networks (VPN) 802.1x authentication 802.1x authentication Industry demanded better option Industry demanded better option

21. Wi-Fi Protected Access (WPA) Improved Data Encryption Improved Data Encryption Temporal Key Integrity Protocol (TKIP)Temporal Key Integrity Protocol (TKIP) Per-packet mixing function Per-packet mixing function Message Integrity Check (MIC/Michael) Message Integrity Check (MIC/Michael) Extended Initialization Vector (IVR) Extended Initialization Vector (IVR) User Authentication User Authentication 802.1x802.1x Extensible Authentication Protocol (EAP)Extensible Authentication Protocol (EAP) Multiple Options (TLS, TTLS, PEAP …) Multiple Options (TLS, TTLS, PEAP …) Greenfield implementations easier Greenfield implementations easier

22. 802.11i Wi-Fi Protected Access 2 (WPA2) Wi-Fi Protected Access 2 (WPA2) Advanced Encryption Standard (AES) Advanced Encryption Standard (AES) Backwards compatible with WPA Backwards compatible with WPA Federal Information Processing Standards (FIPS) compliant Federal Information Processing Standards (FIPS) compliant

23. QoS Issues Latency/Delay Latency/Delay Time to deliver a packetTime to deliver a packet Variable – Congestion Variable – Congestion Fixed – Packet encoding/decoding Fixed – Packet encoding/decoding Jitter Jitter End-to-End latency differenceEnd-to-End latency difference Loss Loss Packet dropsPacket drops

24. Original 802.11 QoS Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) “Listen before talking”“Listen before talking” Distributed Coordination Function (DCF) Distributed Coordination Function (DCF) Clear Channel AssessmentClear Channel Assessment Interframe SpaceInterframe Space Contention Window (Random backoff)Contention Window (Random backoff) Point Coordination Function (PCF) Point Coordination Function (PCF) AccessPoint (AP) is “traffic cop”AccessPoint (AP) is “traffic cop” Stations Transmit only when polledStations Transmit only when polled No ContentionNo Contention Not widely implementedNot widely implemented

25. 802.11e Hybrid Coordination Function (HCF) Hybrid Coordination Function (HCF) 2 modes2 modes Enhanced Distributed Channel Access (EDCA) Enhanced Distributed Channel Access (EDCA) HCF Controlled Channel Access (HCCA) HCF Controlled Channel Access (HCCA) Eight priority levels Eight priority levels Varying backoff times Varying backoff times

26. 802.11e Uses Video Video Multimedia Streaming Multimedia Streaming Voice over Wireless Voice over Wireless

27. 802.11n Increased bandwidth ~100Mbps Increased bandwidth ~100Mbps 2 competing groups 2 competing groups Task Group N (TGn)Task Group N (TGn) 5Ghz Spectrum/40Mhz Channels 5Ghz Spectrum/40Mhz Channels World Wide Spectrum Efficiency (WWiSE)World Wide Spectrum Efficiency (WWiSE) 2.4GHz Spectrum/20MHz Channels 2.4GHz Spectrum/20MHz Channels Multiple Input Multiple Output (MIMO) Multiple Input Multiple Output (MIMO) Additional antenna’sAdditional antenna’s Greater increase in bandwidthGreater increase in bandwidth