multiplexing

In telecommunications and computer networks , multiplexing (also known as muxing ) is a method by which multiple analog message signals or digital data streams are combined into one signal over a shared medium. The aim is to share an expensive resource. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in... telegraphy, and is now widely applied in communications.

A device that performs the multiplexing is called a multiplexer (MUX), and a device that performs the reverse process is called a demultiplexer (DEMUX).

Types of multiplexing:
space-division multiplexing (SDM), frequency-division multiplexing (FDM), time- division multiplexing (TDM), and code division multiplexing (CDM).

In wireless communications , multiplexing can also be accomplished through alternating polarization (horizontal/vertical or clockwise /counterclockwise ) on each adjacent channel and satellite, or through phased multi-antenna array combined with a Multiple-input multiple- output communications (MIMO) scheme.

>Application:
Telegraphy,Telephony,Video processing,Digital broadcasting,Analog broadcasting.