Multiplexing

Intro multiplexer and its types

1. Multiplexing

2. Multiplexing It is a technique which allows to a send multiples signals over a single data link. In simple words sharing of medium between multiple signals. Multiplexer : it is a device that combine multiple signals into one signal. Demultiplexer : it is a device that separate the multiplexer signal

3. Multiplexer and Demultiplexer :

4. Multiplexing types

5. ANALOG AND DIGITAL Data can be analog or digital. Analog data are continuous and take continuous values. Digital data have discrete states and take discrete values. Signals can be analog or digital. Analog signals can have an infinite number of values in a range; digital signals can have only a limited number of values.

6. Comparison of analog and digital signals

7. Frequency Division Multiplexing FDM an analog multiplexing techniqe.Every input signal is modulated with carries frequency to change its characteristics (frequency).

8. Frequency Two signals with the same amplitude and phase but different frequencies

9. Wave Division multiplexing (WDM) It is an analog technique. It combines multiple wavelength of optical signal to transmit in single optical fiber .

10. wavelength A wavelength is a measure of distance between two identical peaks (high points) or troughs (low points) in a wave  -- a repeating pattern of traveling energy like light or sound.

11. Time Division Multiplex (TDM) TDM is a digital multiplexing technique. Every transmitter is assigned a time slot to transmit its signal. Synchronous TDM Asynchronous TDM

12. Time Division Multiplex (TDM)

13. Synchronous TDM   Time slots are fixed. Each source is given it's time slot at every turn due to it. This turn may be once per cycle, or several turns per cycle ,if it has a high data transfer rate, or may be once in a no. of cycles if it is slow. This slot is given even if the source is not ready with data. So this slot is transmitted empty. 

14. Asynchronous TDM: Asynchronous TDM:  In this method, slots are not fixed. They are allotted dynamically depending on speed of sources, and whether they are ready for transmission.