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802.11 on Campus. Philippe Hanset University of Tennessee phanset@utk.edu. Story of UT Wireless Project. 8 Pilots in Summer 2000 Vendor testing Immediate success in CS, MBA, Architecture Instructed in October 2000 to take campus wireless by fall 2001. A Wireless plan in 2 days !
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802.11 on Campus Philippe Hanset University of Tennessee phanset@utk.edu Campus Workshop, Atlanta
Story of UT Wireless Project • 8 Pilots in Summer 2000 • Vendor testing • Immediate success in CS, MBA, Architecture • Instructed in October 2000 to take campus wireless by fall 2001. • A Wireless plan in 2 days ! • AP/Sq Foot based on pilots (from 1500 sq feet/AP to 8000 sq feet/AP) • Power over Ethernet to the rescue Campus Workshop, Atlanta
Scope of UT Wireless Project • $4.35M project budget • 130 buildings covering 15M net assignable sq ft. • 32,000 potential users on campus. Campus Workshop, Atlanta
Design Guidelines • Considering the complexity and early stage of Mobile IP, UT decided to provide roaming to wireless users through the extensive usage of VLAN-trunks • Wireless-VLANs should prevent IP contention in local subnets • Users migration pattern dictates the shape/spreading of the VLANs • IP only, filtered at the Access-Point Campus Workshop, Atlanta
Design Guidelines (cont.) • Per user/per session authentication/encryption • WEP is not scalable • RADIUS and LDAP • Problem of OS support, most solutions are proprietary • RF site survey with 802.11a in mind: SNR of 25 dB at 2.4 GHz translates by extrapolation to ~18dB at 5 GHz (path loss due to higher frequency) • Simultaneous support for 802.11b and 802.11a No interferences between the two, b goes further but a goes faster Campus Workshop, Atlanta
802.11b versus 802.11a Campus Workshop, Atlanta
802.11b versus 802.11a (cont.) Campus Workshop, Atlanta
802.11a • Air is cleaner at 5 GHz • less co-channel interferences e.g.: Bluetooth, HomeRF, Cordless phones (inherent to FCC U-NII regulations) • no microwave ovens interferences Campus Workshop, Atlanta
2.4 GHz ISM Band Required SNR: 1 Mbps: 4 dB 2 Mbps: 7 dB 5.5 Mbps: 11 dB 11 Mbps: 16 dB 5 GHz U-NII Band Required SNR: 6 Mbps: 11 dB 12 Mbps: 14 dB 24 Mbps: 19 dB 54 Mbps: 28 dB Sensitivity (vendor specific) Courtesy of : Campus Workshop, Atlanta
Coverage Courtesy of : Campus Workshop, Atlanta
A few disadvantages of 802.11a • Digital Signal Processing and Power Amplification need more energy at 5 GHz (Battery, Heat) • Higher propagation loss due to higher frequency • Pathloss • Building penetration loss • Card-bus is required to support higher data rates (older laptops obsolete) • Access-Points must be equipped with faster CPU (possible limitation due to Power over Ethernet) Campus Workshop, Atlanta
Wireless Survey • Walkthrough with built-in survey tool from ORINOCO • Simulation with tools like SURVEYOR from WirelessValley (based on AutoCAD drawings) Campus Workshop, Atlanta
Management Tools • Network Management Integration • Wireless Scanners • Anritsu MS2711a up to 3 GHz Battery powered $ 7,450 • Adventest R3131A-74 up to 3 GHz, $ 10,445 • HP 8595E up to 6.5 GHz $21,300 • Wireless Sniffers • Network Associates (www.sniffer.com) • WildPackets • Acceptable Usage Policy plays a key role • (www.sniffer.com) Campus Workshop, Atlanta
make your own AP • www.linux-wlan.com Campus Workshop, Atlanta
Wireless LAN discussion list • wireless-lan@listserv.educause.edu Campus Workshop, Atlanta
For the curious • OFDM for Wireless Multimedia Communication by Richard D.J. van Nee, Ramjee Prasad ISBN: 0890065306 • Wireless Communicationsby Theodore S. Rappaport ISBN: 0133755363 • The IEEE 802.11 Handbook: A Designer's Companionby Bob O'Hara, Al Petrick ISBN: 0738118559 Campus Workshop, Atlanta