Definition: 802.11a is a
WLAN communication standard. 802.11a is one of the wireless
Ethernet standards in the 802.11 series.
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.
Examples:
Though it helps improve network performance and reduce interference, the range of an 802.11a signal is limited by use of the high 5 GHz frequency. An 802.11a AP transmitter may cover less than one-fourth the area of a comparable 802.11b AP. Brick walls and other obstructions affect 802.11a wireless networks to a greater degree than they do comparable 802.11b networks.
