1.3 Types of Computer Networks
The three basic types of computer networks are as follows:
2) Metropolitan Area Networks
3) Wide Area Networks
4) Wireless Networks
5) Internet
1.3.1
Local Area Network (LAN)
A local area network is relatively smaller and privately owned network with the maximum span of 10 km. to provide local connectivity within a building or small geographical area. The LANs are distinguished from other kinds of networks by three characteristics:
(i) Size
(ii) Transmission technology, and
(iii) Topology
Metropolitan Area Network is defined for less than 50 km. and provides regional connectivity typically within a campus or small geographical area. It is designed to extend over an entire city. It may be a single network such as cable television, network, or it may be a means connecting a ņumber of LANs into a large network, so that resources may be shared LAN LAN as well as device to device. For example, a company can use a MAN to connect to LANs in all of its offices through out a city.
Wide Area Network provides no limit of distance. In most WAN, the subnet consists of ty distinct components. Transmission lines also called circuits or channels and routes.Transmission-lines are used for moving bits between machines, whereas routers are used connect two or more transmission lines.
A WAN provides long-distance transmission of data, voice, image and video information over large geographical areas that may comprise a country, a continent or even the who world. In contrast to LANs (which depend on their own hardware for transmission), WANs may utilize public, leased or private communication devices usually in combination and spai distance of unlimited number of miles. A WAN that is wholly owned by a single company is often referred to as an enterprise network.
Mobile computers, such as notebook computers and personal digital assistants (PDAs), the fastest-growing segment of the computer industry. Many of the owners of these computers have desktop machines on LANs and WANs back at office and want to be connected to the home base even when away from home or en route. Since having a wired connection is impossible in cars and airplanes, there is a lot of interests in wireless networks. Wireless networks.Wireless networks have many uses. A common one is the potable office. People on the road often want to use their portable electronic equipment to send and receive telephone calls, faxes, electronic mail, read remote files, login on remote machines and so on and do this f anywhere on land, sea or air.
Many networks exist in the world, often with different hardware and software. People connects to one network often want to communicate with people attached to a different one. This requires connecting together different, and frequently incompatible networks, sometime: using machines called gateways to make the connection and provide the necessary translation both in terms of hardware and software. A collection of interconnected networks is called internetwork or internet.
