Computer Knowledge: Data Communication in Networks for IBPS, SBI and Other Competitive Exams

Data Communication in Networks

Communication:

The term communication means sending or receiving information. When we communicate, we share information or data. This sharing can be local or remote access. A communication system can be defined as the collection of hardware and software that facilitates inter system exchange information between different devices.

Data Communication

Data communication is the exchange of data between two devices using some form of transmission media. It includes the transfer of data or information and the method of preservation of data during the transfer process. This data transfer(communication) is done between a centralised computer and remote terminals or between two or more computer centres over established communication links. Data is transferred from one place to another in the form of signals.

There are three type of signals:

1) Digital Signal: In digital signal, data is transmitted in the electronic form of data. i.e., Binary digits ( 0 or 1).

2) Analog Signal: In analog signal, data is transmitted in the form of radio waves like in telephone line.

3) Hybrid Signal: Hybrid signals have properties of both analog signal and digital signal.

Types of Communication Channels:

The communication channel refers to the direction of signal flow between two linked devices.

1) Simplex Channel: In this channel, the flow of data is always in one direction, with no capability to support response in other direction. This communication is unidirectional. Only one of the communicating devices transmits information and the other can only receive it i.e., Radio, Television, Keyboard, etc.,

2) Half Duplex Channel: In this channel, the data can flow in both directions, but not at a same time. When one device transmits information, then other can only receive at that point of time. Ex:- Walkie-Talkies.

3) Full Duplex Channel: In this channel, the flow of data is in both directions at a time i.e., both stations can transmit and receive information simultaneously. Ex:- Wireless handset (mobile phones)

Communication Media:

Communication media of a network refer to the transmission media or the connecting media used in the network. It can be broadly defined as anything that can carry information from a source to destination. It refers to the physical media through which communication signals can be transmitted from one point to another.