802.11a wireless networks support a maximum theoretical bandwidth of 54 Mbps. 802.11a's principal advantage over 802.11b, that supports 11 Mbps, is improved performance. However, 802.11a access points (APs) and adapters also cost significantly more than their 802.11b counterparts.
802.11a transmits radio signals in the frequency range above 5 GHz. This range is "regulated," meaning that 802.11a gear utilizes frequencies not used by other commercial wireless products like cordless phones. In contrast, 802.11b utilizes frequencies in the unregulated 2.4 GHz range and encounters much more radio interference from other devices.

