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