Data Communication

Definition:-

Data Communications is the transfer of data or information between a source and a receiver. The source transmits the data and the receiver receives it. Data Communication is the transfer of data, the method of transfer and the preservation of the data during the transfer process.
The purpose of Data Communications is to provide the rules and regulations that allow computers with different disk operating systems, languages, cabling and locations to share resources. The rules and regulations are called protocols and standards in Data Communications.


Components:-

The five components are :

1. Message - It is the information to be communicated. Popular forms of information include text, pictures, audio, video etc.

2. Sender - It is the device which sends the data messages. It can be a computer, workstation, telephone handset etc.

3. Receiver - It is the device which receives the data messages. It can be a computer, workstation, telephone handset etc.

4. Transmission Medium - It is the physical path by which a message travels from sender to receiver. Some examples include twisted-pair wire, coaxial cable, radiowaves etc.

5. Protocol - It is a set of rules that governs the data communications. It represents an agreement between the communicating devices. Without a protocol, two devices may be connected but not communicating.

Modes of Data Communication:-

There are 3 modes of communication:

1) Simplex:- In Simplex mode, the communication can take place in only one direction. In this mode, a terminal can only send data and cannot receive it or it can only receive data but cannot send it. It means that in this mode communication is uni-directional.

2) Half-Duplex Mode :- In Half-duplex mode, the communication can take place in both directions, but only in one direction at a time. In this mode, data is sent and received alternatively. It is like a one-lane bridge where two-way traffic must give way in order to cross the other.

3) Full-Duplex Mode:- In Full-duplex mode, the communication can take place in both directions simultaneously, i.e. at the same time on the same channel. It is the fastest directional mode of communication.