Multiplexing

 Multiplexing is the process of simultaneously transmitting two or more individual signals over a single communication channel. Due to multiplexing, it is a possible to increase the number of communication channels so that more information can be transmitted. The typical applications of multiplexing are in telemetry and telephony or in the satellite communication.

Concept of Multiplexing

 

The multiplexer receives a large number of different input signals. Multiplexer has only one output which is connected to the single communication channels. The multiplexer combines all input signals into a single composite signal and transmits it over the communication medium. Sometimes, the  composite signal is used to modulate a carrier before transmission. At the receiving  end of communication link, a demultiplexer is used to sort out the signals into their original form.

Types of Multiplexing

There are three basic types of multiplexing. They are as under:

(i) Frequency Division Multiplexing(FDM)

(ii) Time Division Multiplexing(TDM)

(iii) Wavelength Division Multiplexing(WDM)