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

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

3. What is “Wireless”?

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

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

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

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

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

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

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

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

12. WLAN Selection & Deployment Issues n Top 3 Deployment Concerns 1. RF Survey 2. RF Survey 3. RF Survey n Use of appropriate antennas n Airspace ownership (policy issue?) n Significance of roaming capability n Power over Cat5 media

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

14. Tips N Tricks #1 n Always do a site survey n Vendors think horizontally and not vertically (or “spherically”) n Vendors want success stories n If it’s not standard, avoid it! n 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 n Wireless card will shorten battery life by at least 50% n If it’s the first “big” wireless project, consider a consultant! n Wireless doesn’t have to be “sold”, but you have to test it, announce it, demo it, & have gear readily available n 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 n Avaya.com (Lucent) n Symbol.com (Intel) n Cisco.com (Aironet) n Proxim.com n Mobilestar.com n www.wlana.com/intro/introduction/index.html n www.bluetooth.com n http://www.apple.com/airport/ n http://www.dell.com/us/en/hied/topics/vectors _1999-wireless.htm

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

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