multiplexer

                MULTIPLEXER  AND  ITS  BASIC TYPES .

• Definition.

"Multiplexing is a method or tecnique inwhich multiple analog and digital signals are combined into one single signal over a shared medium".
 Its aims to share source resource .For exammple several phone calls maybe carried from a single wire .

• Simple words.   

      "It is a method  to give a way  to multiple signals  from multiple resources into a single way". 
"You can say it is the only way who combine multiple signals from multiple ways  and transmit them into a single way for data transmission  along its data is called multiplexing".
The device that support multiplexing is called Multiplexer,or MUX.

• Basic types of Multiplexing.

1. Analog multiplexing.
2. Digital multiplexing.

•  Analog multiplexing.

"It is the method that deals with the analog signals with the help of multiplexer is called analog multiplexing".

• Simple words.

The  method to manage analog signals through multiplexer  are known as Analog Multiplexing.

In this method the signals which are used  in analog multiplexing technique are analog in nature .

example. waves of sound from mike rto speakert is the example of analog multiplexing.

 we have two types of analog Multiplexing.

• Fdm(frequency division multiplexing).
• Wdm(wavelength division multiplexing).

1. Fdm(frequency division multiplexing).

This frequency uses various frequencies to combine strreams of data for sending trhem on a communication medium as a single signal.
Example  = Television(Tv)  which sends different channels of frequencies on a single wire .
      

    2.Wdm(wavelength division multiplexing).

In this many srtreams of different wavelengths are transmitted in  Light Spectrum.

if wavelength increases the frequency  of signal decreases. A Prism which can turn differentr wavelength into singleline can be used for output of MUX.

Example  = OPTICAL FIBER CABLE  that uses wdm technique to transfer data frrom its surface.

• Digital multiplexing.

If digital signals arre multiplexed then it is called digital multiplexing.

it is also called TDM (time division multiplexing). In this technique  time frames are divided into several slots . This transmission is used to transmit signals over a single communication channel by aloting  one slot for each message.

It have two basic types are following.

1. Syncronous TDM.
2. Asyncronous TDM. 

1. Syncronous TDM.

In this input is connected to a frame. if thereare numbers of  connectiions then frames is divided into 'n' time slots. One slot is allocated for each input line.
Simple words. 
if we have 3 numbers of inputs then the slots will be designed in three boxes.

2.Asyncronous TDM.

In this technique sampling rate is different  for each signal and common clock  is not required if a slot alloted nothing then this slot will be allocated another device it is used in Asyncronous tdm. 
Simple words  in tis tchnique no one slot will free while transmitting trhe signals all slots will be full .