190 likes | 309 Vues
The University of Tennessee launched an ambitious $4 million wireless project to enhance campus connectivity. Started with pilot tests in Summer 2000, the initiative quickly proved successful, leading to Wi-Fi coverage across 130 buildings and potential access for 32,000 users. The project utilized an innovative approach, combining Power over Ethernet and VLANs for seamless user roaming. With a commitment to providing free wireless access, the initiative has become integral to daily academic operations. Challenges such as equipment costs and ongoing support remain, but the community has embraced this advancement wholeheartedly.
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