Half Duplex Frequency Division Duplexing

A communication method that employs separate frequency bands for transmitting and receiving operations, much like ordinary full duplex FDD. However, in HD-FDD, the transmitting and receiving operations do not occur simultaneously. Instead, the system switches between transmission and reception. While HD-FDD systems still require a pair of frequency bands to operate, they can be beneficial in circumstances where simultaneous transmission and reception are not required, or in devices where isolating the transmitter and receiver for simultaneous operation is challenging or cost-prohibitive. This is common in IoT technologies where simple low power, low cost devices are desirable.