Frequency Division Duplex (FDD)

Frequency-division duplexing (FDD) is a method for establishing a full-duplex communications link that uses two different radio frequencies for transmitter and receiver operation. FDD operation normally assigns the transmitter and receiver to different communication channels. One frequency is used to communicate in one direction, and the other frequency is required to communicate in the opposite direction. The transmit direction and receive direction frequencies are separated by a defined frequency offset.