Network

Introduction:- A network is defined as the connection of two or more than two communicating devices to share the information,videos,pictures,music etc.. The devices can be the computers, printers etc. in which one device sends the data and the other device receives the data or vice versa. This article is specially designed for the computer networks in which the network is formed by connecting two or more than two computers however other devices can also exist in place of computers. The network of the computers can be formed by

using physical (wired) transmission medium or through wireless transmission medium. The physical transmission medium or the guided medium can be twisted pair cables,coaxial cables or optical fibres to transmit information from one end to the another end whereas the wireless transmission medium or the unguided medium are the radio waves,micro waves etc. .

The computer network can be defined into two types:-

1. Simple Network

2. Complex Network

Lets start with its types one by one:-

1. Simple Network:- In simple network,there is only two computers which forms a small and simple network. They are further divided into three types:- Simplex network, Half duplex network, Full duplex network.

a) Simplex Network:- In the simplex network, there are two computers connected with each other in which one computer acts as a sender only and the other computer acts as a receiver only. It means in the simplex form of network, the data can be sent from one computer to the other computer and not vice versa. The data will travel only in one direction. Example:- Keyboard,monitor etc. are the devices that is meant for single purpose only i.e either for sending or for receiving.

b) Half Duplex Network:- In this type of network, the data can be sent in either direction but one at a time. It means, at a time, one computer will be working as a receiver and on the other time it may acts as a sender but not sender and receiver at the same time. In a half duplex network,the whole of the channel capacity is taken by the transmitting device. For example:- Walkie-Talkies are the half duplex system. In it, when one person is talking the other person can hear only and when the other person is talking then the first person can hear only.

c) Full Duplex Network:- In this type of network, both the devices can send and receive the data at the same time means the data can travel in both the direction at the same time. In full duplex network,the channel bandwidth is shared between both the sender and the receiver equally. The other method is just use the two transmission medium: one for the sending and the other for the receiving. Example of the full duplex network is the telephone system. In telephone,we can hear as well as we can talk to another person simultaneously.

2. Complex Network:- In complex network, the complexity increases in the network of the devices. In the complex form of network, there may be tens, hundreds or millions of computers connected together to form the network in order to share the information between them. The complex network can be divide into three types:- LAN(Local Area Network), MAN(Metropolitan Area Network) and  WAN(Wide Area Network).

a) Local Area Network(LAN):- This type of network is used to connect the computers usually within a building,home or inside an office. The size of the LAN is limited from few metres to few kilometres. It is the cheapest form of network if we compare it with the MAN and WAN because it requires typically a single cable to connect to each computer. Coaxial cables, Twisted cables or fibre optics can be used to form a LAN. Wireless LAN also exists in which there is no need to use the cables to connect to each computers. The LAN provides the very high speed of data transmission ranging from 10Mbps to 10Gbps between the computers. A LAN can be formed by using three Network topologies i.e Star, Bus or Ring topologies.

b) Metropolitan Area Network(MAN):- This type of networks covers a large area like a group of buildings, city or a university campus. The size of MAN is in between LAN and WAN. It is designed for a high speed network to send and receive the data quickly. Telephone company network and the cable TV network are the good examples of Metropolitan Area Network.

c) Wide Area Network(WAN):-  This type of network covers the large area like a group of cities, country, continent or even the whole of the world. It is the combination of the two or more LAN’s. To cover a larger distance, leased telephone cable lines or wireless medium is used for the transformation of the information. The best example of the Wide Area Network is the Internet!

Credits:- Yuvraj Salaria