(1) (Frequency Division Duplexing) A transmission method that uses separate channels for the uplink and downlink (transmit and receive). If the channel frequencies are adjacent, a guard band may be used between them to reduce interference. Contrast with TDD.
A means of providing duplex (bidirectional) communications in wireless networks, FDD makes use of separate frequencies for forward and backward channels. FDD is used with both analog and digital wireless technologies, including cordless telephony and cellular. See also analog, cellular, channel, cordless telephony, digital, duplex, frequency, and wireless.