The 802.11a standard uses
the same core
protocol as
the original
[IEEE 802.11
(wireless networking)] standard, operates in [the] 5 GHz band, and uses
a 52-subcarrier orthogonal
frequency-division multiplexing
(OFDM) with a maximum raw data rate of 54 Mbit/s, which yields
realistic net achievable throughput in the mid-20 Mbit/s. The data rate
is reduced to 48, 36, 24, 18, 12, 9 then 6 Mbit/s if required. 802.11a
originally had 12/13 non-overlapping channels, 12 that can be used
indoor and 4/5 of the 12 that can be used in outdoor point to point
configurations.
source - IEEE 802.11a-1999.
(2008, June 25). In Wikipedia, The Free Encyclopedia.
Retrieved June 26, 2008, from
http://en.wikipedia.org/wiki/802.11a
While 802.11a enjoyed a brief period as top dog in the wireless
networking arena, the inherent difficulty in getting wireless signal at
5GHz to pass through solid objects typically makes it a secondary or
tertiary choice for hotspot venues. That said, Hautspot does indeed
sometimes utilize hardware employing 802.11a technology, typically for
line of sight, point-to-point distribution systems. In addition, many
new notebooks have built-in 802.11a/b/g hardware, making 802.11a once
again available to the general public.