802.11a operates in the UNII (Unlicensed National Information Infrastructure) 5GHz band and supports transmission rates up to 54Mbps. 802.11a uses Orthogonal Frequency Division Multiplexing (OFDM), as opposed to the DSSS or FHSS schemes used in 802.11b and 802.11 networks. Due to its higher frequency of operation, the range of 802.11a equipment is less that of lower frequency systems such as 802.11b and 802.11g. This can increase the cost of an 802.11a network, because a greater number of access points may be required. Since it operates in a different RF band, 802.11a cannot work directly with 802.11b or 802.11g equipment. Using multi-mode 802.11a/b/g access points and/or client adapters will resolve this problem.
How to implement 802.11a
Looking for training or advice on 802.11a and other concepts - to implement robust, secure, scalable and reliable wireless networks?