190 likes | 217 Views
Wireless Everywhere on Campus. Philippe Hanset University of Tennessee phanset@utk.edu. Story of UT Wireless Project. 8 Pilots in Summer 2000 Vendor testing (interoperability, encryption…) Immediate success in CS, MBA, Architecture Instructed in October 2000 to take campus Wireless
E N D
Wireless Everywhere on Campus Philippe Hanset University of Tennessee phanset@utk.edu I2 Member Meeting, Virtual Austin
Story of UT Wireless Project • 8 Pilots in Summer 2000 • Vendor testing (interoperability, encryption…) • Immediate success in CS, MBA, Architecture • Instructed in October 2000 to take campus Wireless (WLAN IEEE 802.11b) by fall 2001. • A Wireless plan in 3 days ! • Density of coverage from pilots applied to entire Campus • Power over Ethernet to the rescue I2 Member Meeting, Virtual Austin
Scope of UT Wireless Project • $4M project budget • 130 buildings, covering 15M net assignable sq ft. • 32,000 potential users on campus. I2 Member Meeting, Virtual Austin
Design Guidelines • Use 4 channels (1,4,7,11) instead of 3 non-overlapping as advised by IEEE • 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 also prevent IP contention in local subnets • IP only, filtered at the Access-Point (every AP is a mini-router, limits broadcast) I2 Member Meeting, Virtual Austin
Design Guidelines (cont.) • Per user/per session authentication/encryption • WEP is not scalable • RADIUS and LDAP for central authentication • Proprietary at the moment (IEEE 802.11E ?) • 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. Add a card to the second slot of AP, and campus is 802.11a compliant I2 Member Meeting, Virtual Austin
Deployment • Wireless survey and install was handled by a local contractor (knew the site already) • Simple tool: built-in wireless site survey from Lucent • UT wireless team controlled the contractor’s deployment on a per-building basis • Power over Ethernet cost was optimized by centralizing Cat5 drops (not short path first) This reduces the number of power injectors I2 Member Meeting, Virtual Austin
Business/Admin Model • “Wireless is Free at UT” (wireless cost is included in wired port fee) • How long will it last?…Wireless on desktops is already showing up! • Every .edu person at UT is in LDAP “If you are in LDAP, you are on Wireless” (no registration required, no MAC address) • Detailed RADIUS accounting, just in case • Wireless cards are subsidized at the moment for students, 50% of the cost (incentive to support proprietary solution) I2 Member Meeting, Virtual Austin
As of October 1st 2001 • 60 buildings on Wireless 20 waiting for network upgrade, 50 on hold (phase II) • Budget: $2M, with ~1000 AP installed • 860 Wireless users (accounting from RADIUS!) I2 Member Meeting, Virtual Austin
Evolution of Wireless Usage at University of Tennessee I2 Member Meeting, Virtual Austin
Outgoing (Sept 27) TCP other 45% TCP FTP 20% TCP Gnutella 11% TCP HTTP 10% TCP Kazaa 6% TCP NNTP 3% other 5% Incoming (Sept 27) TCP HTTP 35% UDP other 13% TCP other 20% TCP NNTP 10% TCP Gnutella 8% TCP Kazaa 7% TCP FTP 4% other 3% A day of traffic on Wireless I2 Member Meeting, Virtual Austin
Success in the community • The community embraced it, but the cost of a laptop is still a limiting factor • More than electricity, more than Wired ethernet, the Wireless network has to be up • Business/Law/Architecture schools are relying on Wireless for classes, every day (shutdown for Finals!!!) • Project to connect local schools to Internet2 via point-to-point Wireless IEEE 802.11b or a • By Spring 2002, IPV6 will be supported on UT’s Wireless Network I2 Member Meeting, Virtual Austin
Caveats • Wireless equipment located everywhere • Power over Ethernet design issues (the problem of early adopters) • Wireless proprietary solution great for security and authentication, but major software issues (client incomp., support for OSes) • Control of Wireless Spectrum (Adhoc mode…) AUP plays a key role • “Creative” wireless applications poorly designed • Requests for Wireless printing I2 Member Meeting, Virtual Austin
Wireless LAN discussion list • wireless-lan@listserv.educause.edu I2 Member Meeting, Virtual Austin
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 I2 Member Meeting, Virtual Austin
802.11b versus 802.11a I2 Member Meeting, Virtual Austin
802.11b versus 802.11a (cont.) I2 Member Meeting, Virtual Austin
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 I2 Member Meeting, Virtual Austin
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 : I2 Member Meeting, Virtual Austin
Coverage Courtesy of : I2 Member Meeting, Virtual Austin