September 2003
Intermediate to advanced
304 pages
8h 39m
English
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802.11a: The Betamax of the 802.11 Family
802.11a offers more channels, higher speed, and less interference than other protocols, but it still just isn’t popular.
According to the specifications available from the IEEE (at http://standards.ieee.org/getieee802/), both 802.11a and 802.11b were ratified on September 16, 1999. Early on, 802.11a was widely touted as the “802.11b killer,” as it not only provides significantly faster data rates (up to 54 Mbps raw, or about 27 Mbps actual data), but also operates in a completely different spectrum—the 5 GHz UNII band. It uses an encoding technique called Orthogonal Frequency Division Multiplexing (OFDM).
While the promises of higher speeds and freedom from interference with 2.4 GHz devices made 802.11a sound promising, it came to market much later than 802.11b. It also suffers from range problems: at the same power and gain, signals at 5 GHz appear to travel only half as far as signals at 2.4 GHz, presenting a real technical hurdle for designers and implementers. The rapid adoption of 802.11b only made matters worse, since users of 802.11b gear didn’t have a clear upgrade path to 802.11a (as the two are not compatible). As a result, 802.11a still isn’t nearly as ubiquitous or inexpensive as 802.11b, although client cards and dual-band access points (which essentially incorporate two radios, or a single radio with a dual-band chipset) are coming down in price.
Pros
Very fast data rates: up to 54 Mbps (raw radio rate), with some vendors ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.