The frequency-division multiplexing (FDM) is a method by which the total bandwidth accessible in a communication medium is partitioned into a progression of non-overlapping frequency bands, each of which is utilized to convey a different signal. This permits a solitary transmission medium for example optical fiber to be shared by different autonomous signals. The example of frequency-division multiplexing is radio and television broadcasting, in which numerous radio signals at various frequencies go through the air simultaneously.