Wednesday, October 15, 2008

Why Is It Called 802.11?

Many people wonder what the heck the 802.11a, b, and g stand for. The IEEE (Institute of Electrical and Electronics Engineers), the same people who brought your IEEE-1394 (also called FireWire, iLink, and so forth) is an established standards body that has defined many technologies via its internal open working groups (WGs). 802.11 is named this due to its IEEE working group being group 802.11. IEEE Project 802 is also called the LAN/MAN Standards Committee, or LMSC, and the 802.11 working group handles wireless LANs. Tens of millions of IEEE 802.11 devices have been deployed worldwide and are interoperable. IEEE 802.11 has many flavors. The most widespread today is 802.11b (named after IEEE 802.11 working group B), which operates in the unlicensed ISM (Industrial, Scientific, and Medical) band at approximately 2.45 GHz, and can transmit up to 11 Mbps. Newly available 802.11 flavors include 802.11a and 802.11g. 802.11a and g support speeds up to 54 Mbps (in the standard, proprietary solutions claim faster speeds), and operate in the ISM band, as well as the newly unlicensed U-NII (Unlicensed National Information Infrastructure) band, at 5.2 and 5.8 GHz.
Even though 802.11 is a standard, its availability is restricted in different regions of the world because of varying regulations. Generally, 802.11b in the United States has 13 broadcast channels available for use (3 optimal ones because they are non-overlapping), and 802.11a in the United States supports 140 channels, with 12 non-overlapping optimal channels. However, in France and Spain, the various channels available to 802.11b and g users are severely limited (1 non-overlapping channel), while there are actually more channels available in Japan (13 channels, 3 non-overlapping). Take note: Even though 802.11a provides so many optimal channels, the international legalization of its 5.2 GHz frequency use has not been standardized, so outside-U.S. deployments may run into broadcast legal issues. Another note: The 5.2 GHz U-NII spectrum is also used by microwave landing systems to help planes land in bad weather.

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