Orthogonal Frequency Division Multiplexing - A modulation technique for transmitting large amounts of digital data over radio waves. It is the modulation technique used in 802.11a and 802.11g WLANs.

OFDM is also technically a good choice for use in broadband mobile services such as cellular phones and PDAs. Some U.S. providers are currently considering it as a 4G successor to 3G technologies such as CDMA. Most agree however, that the commercial adoption of OFDM by cellular providers is a long way off, as they are heavily invested in 3G technologies.

OFDM has been around since the late 1960s but it has only recently become commercially viable for use in consumer products such asWLANs. OFDM has become practical for widespread use because it relies on high-speed digital signal processors, and DSPs have only recently become available at prices that make OFDM a competitive technology in the marketplace.