Wireless Networks: Personal, Local, Metropolitan Speedups, Security, Power John Schafer University of Michigan Ann Arbor CSG 10 May
Overview Current choices Speedups coming Power over Ethernet Authenticated Wireless Wireless Personal Area Network: Bluetooth Point-to-point Wireless Metropolitan Area Networking
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
Current Choices *sleep/transmit
Speedups Coming
Speedups of questionable value HiperLAN1 –Only one vendor with plans, wait for HiperLAN2 or a 22 Mbps b –First meeting May 8-12, 2000 –Skip it and wait for a, 54 Mbps 10 Mbps Frequency Hopper (IEEE ) –Needs FCC rule change, seems unlikely
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
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
Authenticated Wireless Radius client in access point IEEE 802.1x is working on a standard Lucent first to market ahead of standard
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
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
Adapting IEEE 802.1x to 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
Bluetooth Wireless Personal Area Network (PAN) IEEE Asynch data and up to 3 voice channels Data: asymmetric 721 Kbps/57 Kbps, symmetric Kbps Uses same 2.4 GHz band as Fast Frequency Hopper, 1600 hops/sec. Interferes with WLANs
Ericsson Bluetooth Module
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
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