802.11g
was
the third
modulation standard for Wireless LAN. It works in the 2.4 GHz band
(like 802.11b) but
operates at a maximum raw
data rate of 54 Mbit/s, or
about 19 Mbit/s net throughput (identical to 802.11a
core, except for
some additional legacy overhead for backward compatibility). 802.11g
hardware is fully backwards compatible with 802.11b
hardware. Details
of making b and g work well together occupied much of the lingering
technical process. In an 11g network, however, the presence of a legacy
802.11b participant will significantly reduce the speed of the overall
802.11g
network.
The modulation scheme used in 802.11g
is orthogonal
frequency-division
multiplexing (OFDM) copied from 802.11a
with data rates of 6, 9, 12,
18, 24, 36, 48, and 54 Mbit/s, and reverts to CCK (like the 802.11b
standard) for 5.5 and 11 Mbit/s and DBPSK/DQPSK+DSSS for 1 and 2
Mbit/s. Even though 802.11g
operates in the same frequency band as
802.11b, it can achieve higher data rates because of its heritage to
802.11a.
source - IEEE 802.11g-2003.
(2009, June 8). In Wikipedia, The Free Encyclopedia.
Retrieved August 15, 2009, from
http://en.wikipedia.org/wiki/802.11g