Multiplexing in communication
Multiplexing
Multiplexing is a technique, which allows many users to share a single communication channel (wire, cable, radio link, fiber optic cable, satellite) simultaneously. So a number of information sources share the same communication channel. Information transmitted can be either voice (telephone signals) or data (computer signal, images, video etc). Well-known application of multiplexing is telephone communication system. Various multiplexing techniques are: FDM, TDM, CDM.
Suppose there are 4 users at one end and another 4 users at other end. Note that each user requires one cable to transmit their information. If the distances are small, the cost of the wire can be tolerated. Imagine a person communicating from India to US . If the persons are separated geographically long, the cost of the channels will be high. This is where multiplexing is used, where one single wire (channel) is used to establish communication among all the users.
The major multiplexing techniques available are:
- Frequency Division Multiplexing (FDM)
- Time Division Multiplexing (TDM)
- Code Division Multiplexing (CDM)
Note: Time & Frequency are important resources in communication system.
