Frequency Division Multiplexing (FDM) Definition/Meaning:
form of multiplexing in which the
bandwidth of the transmission medium is
divided into logical channels over which multiple messages can be simultaneously
transmitted. FDM is commonly used worldwide to combine multiple voicegrade telephone signals: 4000 hertz (Hz) is allocated for each channel, 3000 Hz
per signal plus a 500 Hz guard band (unused frequency band) on either side of
Each signal starts at DC. but the different signals are raised to
different frequencies so that the signals do not overlap. Despite the guard
bands, strong signal spikes at the edges of a channel can overlap into the next
channel, causing noise interference.
See also broadband networking.