DCN | Lecture 2 | Basic Block Diagram of Data Communication System

Block Diagram of Data Communication System

Figure  shows  the  basic  block  diagram  of  a  typical  Data Communication  System.  This  can  further  be broken  down  to three;  the  source  system,  transmission  system  and destination system. 

1.  Source :- The  source  generates  the  information  or  data  that  will  be transmitted  to  the  destination.  Popular  forms  of  information include text, numbers, pictures, audio, video or a combination of  any  of  these.  Information  are  put  together  in  analog  or digital form and broken  into  group  or  segment of data called packets. Each packet consists of the following: 
i. the actual data being sent 
ii. header 
iii. information about the type of data 
iv. where the data came from 
v. where it is going, and  
vi. How it should be reassembled so the  message  is  clear and in order when it arrives at the destination.  

2.  Transmitter :- The transmitter a  device  used  to convert  the  data  as per the destination requirement.  For example a modem, converts  the analog  (telephonic)  signal  to  digital  (computer)  signals  and alternatively digital to analog.   

3.  Transmission Medium :- The transmission  medium  is  the  physical path  by  which  data travels  from  transmitter  to  receiver.  Example  of  such channels  is  copper  wires,  optical  fibers  and  wireless communication channels etc.  

4.  Receiver :- This  receives  the  signals  from  the  transmission  medium  and converts  it  into  a  form  that  is  suitable  to  the  destination device. For  example,  a  modem  accepts  analog  signal from  a transmission channel and  transforms it into digital bit stream which is acceptable by computer system.  

5.  Destination :- It is simply a device for which source device sends the data. 


See Previous Lecture -

DCN | Lecture 1 | Data Communication and its System Components