10-Minute Guide To Wi-Fi Standards

There's 801.22a, 802.11b, 802.11g, pre-N, 802.11i, MIMO, and more. How can you sort out the mess of Wi-Fi standards? Here's the rundown on what the major standards are, and what you need to know about them, from Brian Hernacki, architect, Symantec Research Labs, Cupertino, Calif.,

802.11- This is the overlying architecture for a series of Wi-Fi standards, all with letters following 802.11 (a, b, etc.). This family of standards was first introduced in 1997, but the Institute of Electrical and Electronics Engineers, Inc. (IEEE), the standards body for all things Wi-Fi, didn't approve them until 1999. The 802.11 family of standards provides protocols designed for local area networks and the devices that support them and connect with them.

It's not that wireless networking was unworkable before the introduction of 802.11, according to Hernacki, but any connections before were designed for packets transmitted over a wide variety of radio signals. Due to the wide range of signals in use, wireless networking this way was too cumbersome and, therefore, never enjoyed wide adoption, Hernacki says.

802.11a This was the first of the IEEE standards for wireless LAN. Like the underlying 802.11 architecture, 802.11a was introduced in 1997 and approved in 1999. This enabled commodity-type access points, from Linksys, Netgear, et al.

"It's kind of a footnote in wireless history now," Hernacki says. "It didn't receive much adoption because it operates in the 5 Ghz band, which doesn't penetrate through objects very easily. Therefore, there were problems with absorption of the signal throughout an office. There were products (wireless access points, routers and cards) built for this standard, but I've never seen any of them."

The problem with signal absorption more than outweighed the maximum 54 Mbs speed, Hernacki adds. Some 802.11a products and networks may still exist in some remote areas of the country.

802.11b This was the first wireless standard to receive wide adoption. Operating at 2.4 Mhz, signals with this standard didn't have the absorption problems of the 802.11a standard, but the slow speed (11 Mbps under optimal conditions) also meant that anyone used to broadband in an office or home setting would see achingly slow speeds. Adoption started picking up, as wireless LANs, chips, etc., started becoming available in the late 1990s and early 2000. Some older equipment still uses 802.11b, though slow speed and signal interference from other 802.11b users can be a problem in locations where there are several users in a small space, according to Hernacki.

However, the average age of a laptop is less than three years, so much of the 802.11b equipment has been replaced, though the environment still exists in some many installations where speed isn't critical.

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