Types of multiplexing

Question

Explain different types of multiplexing?

Answer 1

 Multiplexing is of three types:

a)Frequency division multiplexing

b) Wavelength division multiplexing

c) Time division multiplexing

Frequency division multiplexing : In FDM analog signals are combined into a single signal and then transmitted. This technique is used whenever the bandwidth of the link is greater than the combined bandwidth of the signal. In FDM the signal is modulated with the carrier frequency. This modulated signal is then combined into a single signal and then it is transmitted through the link.

Wavelength division multiplexing : It is same as that of the FDM, the difference is that it involves optical signal in place of analog signal, the optical signals are combined and then it is transmitted through the fibre optic channel. These signals are of different frequency, the difference lies in the fact that the frequency is very high.

Time division multiplexing :  It is a digital multiplexing technique; the different digital signals share the time portion of the link. Digital signal are combined into one time shared link. This does not mean that it cannot produce the analog signal, the analog signal is then converted into the digital signal, multiplexed and then it is transmitted.