We have been using wireless ethernet at Guru Labs for sometime. It is a pretty advanced deployment as we have configured our Cisco access points to broadcast multiple ESSIDs, each with unique security settings. One requires WPA, another WEP, and another is completely open (yet firewalled). Each ESSID is bridged to separate 802.1q VLANs on our network. This is done via the frame tagging and ESSID mapping capabilities within each access point.
This setup is working very well for us.
The first step in deploying a wireless network for maximum performance is to use non-overlapping channels. With 802.11b and 802.11g there are 3 non-overlapping channels. Channels 1,6, and 11. The best practice is to use one of those three. Any "good" access point by default will select the least congested one. This knowledge is pretty widely known.
Today I did a scan and found another access point in the building operating on channel 3. The Guru Labs' access points are operating on channels 6 and 11. I was wondering how much channel 3 is overlapping into channel 6. I went searching to find a information on how the channels overlap with each other. It turns out that this information is not commonly known. After much digging, I finally found this nugget on the web page:
http://www.hyperlinktech.com/web/band_pass_filters.php
http://www.hyperlinktech.com/web/copyrighted_images/channel_chart.gif
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