What is IEEE 802.11?

IEEE 802.11 (commonly referred to as "wireless ethernet" and branded as "WiFi") is a set of technology specifications that enable high speed wireless LAN access. Compatibility between 802.11 products is encouraged by the Wireless Ethernet Compatibility Alliance (a good source for 802.11 information).

802.11 operates in the same unlicensed frequency range as Bluetooth and HomeRF. It is optimized for data transmission up to 100 meters within offices and campus LANs. The specs are based upon wired ethernet technology. As such, 802.11 behaves similarly to wired ethernet when transmission problems occur: It waits, then retransmits in response to interference. This works well with data but not necessary with voice or other applications that benefit from some amount of guaranteed throughput.

There are subsections within the spec. The most commonly deployed variant is 802.11b, often referred to simply as "802.11". A higher speed variant (confusingly enough named 802.11a) is also on the rise.

For more information on how 802.11 relates to other wireless technologies such as Bluetooth, HomeRF, and J2ME, please refer to my "Rapid Fire Wireless 101" webcast, available from:
http://java.sun.com/jdc/onlineTraining/webcasts