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Wireless Networks: Personal, Local, Metropolitan

Wireless Networks: Personal, Local, Metropolitan. Speedups, Security, Power John Schafer University of Michigan Ann Arbor CSG 10 May 2000 jbs@umich.edu www.itcom.itd.umich.edu/wireless/. Overview. Current choices Speedups coming Power over Ethernet Authenticated Wireless

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Wireless Networks: Personal, Local, Metropolitan

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  1. Wireless Networks: Personal, Local, Metropolitan Speedups, Security, Power John Schafer University of Michigan Ann Arbor CSG 10 May 2000 jbs@umich.edu www.itcom.itd.umich.edu/wireless/

  2. Overview • Current choices • Speedups coming • Power over Ethernet • Authenticated Wireless • Wireless Personal Area Network: Bluetooth • Point-to-point Wireless Metropolitan Area Networking

  3. Terminology • Access point (AP), station adapter • WEP (Wired Equivalent Privacy) • Encryption of data packets, 40 or 128 bit • Access control table - list of MAC addresses • Speeds are nominal, throughput is about one half

  4. Current Choices *sleep/transmit

  5. Speedups Coming

  6. Speedups of questionable value • HiperLAN1 • Only one vendor with plans, wait for HiperLAN2 or 802.11a • 22 Mbps 802.11b • First meeting May 8-12, 2000 • Skip it and wait for 802.11a, 54 Mbps • 10 Mbps Frequency Hopper (IEEE 802.11) • Needs FCC rule change, seems unlikely

  7. Power over Ethernet • Conduit to power AP: $800, Enet: $300 • Several methods being discussed (IEEE) • Use spare wire pairs on CAT5 cable • Couple DC power on signal pairs • Smart - only turn on power to responsive device • Applications - VoIP phones, Security, AP’s • Built into future switches/hubs • Standard due 3Q2001

  8. Problems with current security • Encryption keys set the same for all users • Password for network given to all users • Access control table updated manually • Access control based on MAC address - spoofable

  9. Authenticated Wireless • Radius client in access point • IEEE 802.1x is working on a standard • Lucent first to market ahead of standard

  10. Lucent Access Server AS-1000 • Diffie-Hellman key exchange • Per user, per session key used for WEP encryption • Setup PPP link • RADIUS client in AP - RADIUS servers - Kerberos • Limitations: • First version - No Roaming • User must exist in authentication system before first connection

  11. Merit RADIUS system, ABS, PTS • State-wide: 800 modem pools, 160 RADIUS servers • Accounting and Billing System (ABS) • Protection Server (PTS) • AS-1000 looks like a modem pool • Auto-subscribe, monthly billing, usage charges, grant access based on PTS groups

  12. Adapting IEEE 802.1x to 802.11 • Based on existing standards • Extensible Authentication Protocol (EAP) • RADIUS • Dynamic key management • Roaming - handoff of keys to AP • Unauthenticated VLAN support - access to registration/enrollment server (optional) • Expected Summer 2001 • http://grouper.ieee.org/groups/802/1/index.html

  13. Bluetooth • Wireless Personal Area Network (PAN) • IEEE 802.15 • Asynch data and up to 3 voice channels • Data: asymmetric 721 Kbps/57 Kbps, symmetric 432.6 Kbps • Uses same 2.4 GHz band as 802.11 • Fast Frequency Hopper, 1600 hops/sec. • Interferes with 802.11 WLANs

  14. Ericsson Bluetooth Module

  15. Bluetooth - Applications • Replace infrared and custom cables • Computers, PDAs, Palmtops, Mobile phones • Headsets, Digital cameras, Automobiles • Bluetooth SIG has 1400 member companies • Plan to migrate your WLANs to 5 GHz band • http://www.bluetooth.com/ • http://www.bluetooth.net/

  16. Wireless Metropolitan Area Nets • Point-to-point and point-to-multipoint • Unlicensed (2.4 GHz ISM band) • WLAN hardware plus external antennas • Speed: 1-5 Mbps, Distance: <20 miles • Licensed spectrum • Local Multi-point Distribution Service (LMDS) • FCC auction in spring of 1998, 38 GHz band • Line-of-site, up to 5 miles, up to 45 Mbps • Laser

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