Orthogonal Frequency Division Multiplexing (OFDM) is a physical layer encoding technology for transmitting signals through the RF. This method breaks one high-speed data carrier into several lower-speed carriers. These are in turn transmitted in parallel across that particular RF spectrum. The 802.11a subcommittee has elected to use the transmission technique for their standard in the 5 GHz UNII (Unlicensed National Information Infrastructure) bands. OFDM is also used in the 2.4 GHz ISM band as the physical layer standard for the 802.11g standard.