What is frequency division multiplexing (FDM)?

Frequency Division Multiplexing (FDM) is a technique where the total available bandwidth of a transmission medium is divided into several non-overlapping frequency bands. Each of these discrete sub-bands carries a separate, independent data stream. This method allows multiple signals to be transmitted simultaneously over the same medium without interfering with one another. A classic example is how a single cable line can carry hundreds of different television channels simultaneously, each assigned to its own frequency slice. Other options describe completely different technologies. For example, a signal jumping from band to band describes Frequency Hopping Spread Spectrum (FHSS), and dividing a signal into discrete packets describes packet radio, not FDM.