E-Seminar Update: Wireless Lans

Following are the results of the interactive polls conducted during the April 26 eWeek eSeminar, "Wireless LANs: Enterprise networking outside the box." Also included are answers to questions posed during the eSeminar by attendees, an audience

What happens when two WLANs end up in the same location?

If two 802.11b WLANs are set up in close proximity to each other, clients can see the access points of both WLANs. Access, however, is dependent upon user authorization and, if set up correctly, MAC address authorization. So users of one system should not be able to access another system without authorization. Unless there is high saturation of access points and clients in a small area, interference should not be a problem.

We are implementing wireless systems on our college campus. Is interference from other electronic devices a problem?

Because 802.11b WLANs share the same 2.4GHz band as some cordless phones and microwave ovens, among other things, the potential for interference exists. However, 802.11b equipment uses Direct Sequence Spread Spectrum to avoid interference. A site survey can pinpoint areas where interference might be a problem.

Are there plans to update the WEP encryption standard to something less hackable?

Yes, the Institute of Electrical and Electronics Engineers is working on an updated standard for Wireless Equivalent Privacy to improve security, and equipment vendors are adding enhancements that make WEPs original security problems a nonissue.

How bad is the security issue if you can transmit only in your building?

Actually, tests have shown that WLAN transmissions can be received outside a building. Someone sitting in a car next to your building, for example, could receive transmissions.

What is the timing and upgrade scenario for 802.11b to 802.11a?

802.11b equipment thats capable of being upgraded to 802.11a will appear this summer, and volume shipments of 802.11a equipment will appear around the first quarter of next year.

Is it best for an organization to wait for the 802.11a products to be released and jump in at that point?

An analyst from Gartner Inc. was quoted in the eSeminar Special Report on WLANs as saying that there is a lot of life left in 802.11b, and that "a" has a lot of issues that need to be ironed out. (See the story at www.eweek.com/links.) A lot depends on how soon you want the technology.

With 802.11a, is there a limitation on the number of access points that can be clustered?

The 802.11a standard calls for a higher numbers of access points in a given area than 802.11b. When we can test 802.11a equipment in the real world, well see what the practical limit is.

What are the concerns when operating Bluetooth and 802.11b networks in the same area?

Interference is the biggest concern, but tests have shown that unless Bluetooth and 802.11b device saturation is inordinately high, the potential for interference is low. If a Bluetooth device is within 3 feet of an access point, however, throughput can be lowered.