IEEE 802.11a standard is an extension to the 802.11 standard.

Just like 802.11-1997, IEEE 802.11a standard also applies to the wireless LANs. However, unlike 802.11 that makes use of 2.4GHz band, 802.11a involves the use of 5GHz frequency band, and allows up to to 54 Mbps in data transfer rates.

802.11a employs an Orthogonal Frequency Division Multiplexing encoding scheme, and not the FHSS or DSSS encoding schemes used in the systems that were designed to use the original 802.11 wireless standard.

Due to the substantial costs that were involved in switching from 2.4GHz systems (based on 802.11 standard) to the corresponding 5GHz devices (i.e. 802.11a standard based systems), there were not many takers of this new standard -in spite of the huge difference in the data transfer rates that 802.11a based systems would have provided over the original 802.11 based devices.

Products based on 802.11a are considered to be Wi-Fi Certified. It make use of eight channels, and is considered less susceptible to RF interference than the 802.11b and 802.11g standards.