Dear readers in this article, we will read about the Types of computer networks and how information is exchanged through computer network.
A computer network means connecting different computers together so that data and information can be exchanged between them, collective use of different types of resources and individuals located in different places, working jointly on a project. Can. The computer network makes it possible to exchange information at a low cost with fast speed and accuracy.
There are several types of networks, among which the most prominent is the worldwide international network ‘Internet’. Different countries develop their own networks.
Examples– Indonet, Sarnet, Marknet, Nikenet, Earnet, i-Net, Software Technology Park (STP) etc.
Introduction to data communication
Communication means sharing data. This sharing can happen in two ways. Local or remote.
For example, communication between two people is called local communication. Whereas the communication of data between the people sitting in the correct places is called remote communication.
There are five main components under the communication of data.
- Message recipients
- Message transmission medium
- Protocol or manual under which both the sender and the receiver of the message exchange messages among themselves.
- Data communication is the transfer of digital or analog data between two or more computer centers that interconnect communication channels.
Benefits of data communication
- saves the time it takes to send data physically or to prepare data.
- files provide fast information.
- Modern computers have full utilization of processing power and storage capacity.
- 4 The accuracy of the files remains.
- 5 Data is exchanged for less cost.
Methods of communication
- Simplex method — In this method, data and information are transmitted in only one direction ie from sender to receiver. But the information and data received in it is not sure.
Examples – such as radio or TV. Broadcasting .
- Semi duplex method
In this, information can be transmitted in both directions. That is, from the sender to the recipient and from the receiver to the sender but from this information can be transmitted in one direction at a time.
Example – telephone conversation
- Full duplex method
In this, information and data can be communicated simultaneously in both directions. Information can be received immediately in this.
Example- video conferencing
1. Depending on the nature of the information
(i) Sound transmission – It involves transmission of sound only.
Examples- radio, television
(ii) Photo Transmission – In this, photo is communicated.
Example – Television
(iii) Facile communication -A document or picture is sent to it.
2. On the basis of mode of transmission
(i) Analog communication – transmitting information in analog signals.
(ii) Digital communication – Information is transmitted by converting analog signals into digital form.
(i) Communication through wire- There are three ways.
(a) Paired cable Communication – It consists of two flakes of thin copper wire, each bunch is sealed in a separate plastic casing.
- They are wrapped on each other.
- It can achieve speeds of 9600 BPS for distances up to 100 meters.
- Local telephone lines are used for long distances, which usually have a speed of about 1200bps.
- Coaxial cable – Coaxial cable is a specially wrapped and wrapped wire in the casing which is capable of transmitting data at high speed.
(b) Co-axial cable – Coaxial cable was made in 1940. It has a solid conductor at the center. There is a mesh structure around the conductor wire and between them both remains as a plastics conductor. The signals are transmitted by a central solid conductor wire. And the wire of the conductor wire is connected to EARTH. It has a higher bandwidth. The signals are carried over a long distance. This type of wire is used in cable TV networks.
- This cable is used in both long distance data communication and local area network only.
- This cable comes with a copper conductor then a layer of insulation over it.
- Coaxial cable has higher band width and data transmission speed than Pair cable.
- With the help of a coaxial cable, data communication can be done between two computers at the same rate from 3600 to 10800 units.
- Coaxial cable is of two types – (i) thinnet (ii) thicknet
(c) Optical Fibre Cable – It is a thin cylindrical tube made of glass, plastic or silica that works on the principle of complete internal reflection of light. Led Or the light containing the signal generated by the laser diode is carried from one place to another through these fibers. Photo diodes made of semiconductors are used to convert light back into signal. In the optical fiber, there is no loss of energy in the transmission of signals and the noise in this is very low and the speed is fast. It has a high bandwidth. Optical fibers are used for long distance communication and transmission of secret signals. Manufacturing of optical fiber in India Hindustan Cables Limited and OTL.