DEFINITION: The 802.11g specification is a standard for wireless local area networks (WLANs) that offers transmission over relatively short distances at up to 54 megabits per second (Mbps), compared with the 11 Mbps theoretical maximum with the earlier 802.11b standard.

Networks employing 802.11g operate at radio frequencies between 2.400 GHz and 2.4835 GHz,  … 
Definition continues below.

802.11G DEFINITION (continued): … The 802.11g specification is a standard for wireless local area networks (WLANs) that offers transmission over relatively short distances at up to 54 megabits per second (Mbps), compared with the 11 Mbps theoretical maximum with the earlier 802.11b standard.

Networks employing 802.11g operate at radio frequencies between 2.400 GHz and 2.4835 GHz, the same band as 802.11b. But the 802.11g specification employs orthogonal frequency division multiplexing (OFDM), the modulation scheme used in 802.11a, to obtain higher data speed. Computers or terminals set up for 802.11g can fall back to speeds of 11 Mbps. This feature makes 802.11b and 802.11g devices compatible within a single network. Modification of an 802.11b access point to 802.11g compliance usually involves only a firmware upgrade.

For a summary of and links to other specifications in the 802.11 family, see 802.xx Fast Reference.
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