Wireless State of the LAN

1. Wireless State of the LAN EDUTEX 2001 San Antonio Doug Jackson Director, Technology Customer Services University of Texas at Dallas

2. Introduction • What is “Wireless”? • Why is Wireless Important? • WLAN Security & Administration • WLAN Selection & Deployment Issues • Tips’N’Tricks • URLs

3. What is “Wireless”?

4. What is “Wireless”? • Cellular? Microwave? Infrared? • Wireless LAN is Spread Spectrum Radio • 3 Basic Topologies- • Infrared (IRDA) • Frequency Hopping (FHSS) and • Direct Sequence (DSSS) • FH greater density, shorter range, slower speed, less prone to interference (79 channels) • DS lower density, greater range, higher speed, more susceptible to interference (15 channels)

5. What is “Wireless”? • Standards (key to interoperability) • IEEE 802.11 • 802.11b- DSSS @11Mbps 2.4GHz • 802.11a- DSSS @54Mbps 5GHz • 802.11g- DSSS @22Mbps 2.4GHz • 802.11e- DSSS @22Mbps w/QoS • 802.11 is “shared ethernet” • 802.11 is “collision avoidance” (CSMA/CA instead of CSMA/CD)

6. Why is “Wireless” Important? • Perfect for “retrofit networking” • No pulling cables • No “building renovation” • Connections to spaces wires can’t • Excellent space optimization • No “computer rooms” • Extend class/meeting rooms • Simple installs, reduced labor costs, lower cost of ownership • Fosters more collaborative activities

7. Why is “Wireless” Important? • Great for travel • Airports (DFW, Austin, etc.) • Hotels • Provides more flexibility • At home (couch potatoes!) • Cafeterias, common areas • Ubiquitous, Anytime, Anywhere network connectivity!

8. Why is “Wireless” Important? • UT Dallas Wireless Projects for 1999-2000: • Library laptops for checkout by students • Largest Classroom building • Conference Center • Ad Hoc networking “kits” • WLAN Projects for 2001 • Student apartments • Student Union • Selected Common Areas

9. WLAN Security & Administration Issues • Only as secure as the wired portion of the network • WEP uses either 40 (default) or 64 bit RC4 encryption • May use VPN for added security • Most vulnerable point is between laptops within same cell • Load balancing, roaming essentially managed by AP’s

10. WLAN Selection & Deployment Issues • Leaders include: • Avaya (Lucent) • Symbol (Intel) • Cisco (Aironet) • Proxim, 3Com, Breezecom, etc. • Vendors embracing WLANs: • Apple (for over a year) • IBM • Dell • (Everybody is doing it!)

11. WLAN Selection & Deployment Issues • Utilize 802.11b standards (or 802.11a) • Consider situational factors • Range- 150ft per cell • Available channels- 3 to 5 • Cell overlap (and failovers) • Potential Interference- microwaves, cellphones (2.4GHz devices) • “Dead” zones- metal, concrete w/rebar, reflective surfaces

12. WLAN Selection & Deployment Issues • Top 3 Deployment Concerns • RF Survey • RF Survey • RF Survey • Use of appropriate antennas • Airspace ownership (policy issue?) • Significance of roaming capability • Power over Cat5 media

13. WLAN Selection & Deployment Issues • Plan for 20-30 users per AP • Locate AP’s considering cell overlap • Plan for 3D, not 2D • Do RF survey with bodies in place • Plan for electrical- both for AP and for laptop battery rechargers • Determine security needs and effective alternatives

14. Tips N Tricks #1 • Always do a site survey • Vendors think horizontally and not vertically (or “spherically”) • Vendors want success stories • If it’s not standard, avoid it! • Co-located access points should be at least 5 channels apart (thus a max of 3) - practice shows 4 apart works with little or no signal degradation

15. Tips N Tricks #2 • Wireless card will shorten battery life by at least 50% • If it’s the first “big” wireless project, consider a consultant! • Wireless doesn’t have to be “sold”, but you have to test it, announce it, demo it, & have gear readily available • Wireless infrastructure can be grown incrementally or purchased “turn key”

16. Tips N Tricks #3 • 11Mb fails to 5.5Mb fails to 2Mb fails to 1 Mb fails to 0 • Who owns the airspace? List of “banned” devices? • Interference: Bluetooth, other AP’s, 2.4GHz phones, microwave • Costs: AP <$650, NIC cards <$150 • Use only 1 segment, if possible, for effective roaming

17. Tips N Tricks #4 • Perform RF site survey with bodies in place • Printing considerations still there, maybe worse! • Don’t put antenna too high! • Wireless is principally a retrofit technology • Plan for 15-25 users per AP with 802.11b

18. Tips N Tricks #5 • 802.11a (54Mbps, 5GHz range) (less potential interference) • Battery life goes down as speeds go up • Power over CAT5 wiring available, no extension cords! • Tradeoffs: range vs. bandwidth vs. cost • Authentication issues? VPN for “best” security?

19. URLs • Avaya.com (Lucent) • Symbol.com (Intel) • Cisco.com (Aironet) • Proxim.com • Mobilestar.com • www.wlana.com/intro/introduction/index.html • www.bluetooth.com • http://www.apple.com/airport/ • http://www.dell.com/us/en/hied/topics/vectors_1999-wireless.htm

20. URLs • Higher Ed Success Stories • Carnegie Mellon http://www.cmu.edu/computing/wireless/ • Buena Vista University http://ebvyou.bvu.edu/ • UT Austin (ACES) http://www.aces.utexas.edu/ • Marquette University Engineering http://www.eng.mu.edu/wireless/ • Andrews University http://www.andrews.edu/wireless/wirelesszone/ • Valdosta State http://www.valdosta.edu/wireless/ • To name a few…

21. URLs • For copies of this presentation: • Email: Jackson@utdallas.edu • For more information: (White papers & more URL’s) www.utdallas.edu/ir/wlans/