Communication through computer networks
- 2. Communication Communication is a process of transferring message from one point to another. The four basic elements of any communication system are: A sender (source),which create the message to be transmitted. A message, information to be communicated. A medium, which carries the message. A receiver, which receives the message.
- 3. Computer network A computer network is a interconnection of computers and computing equipments using either wires or wireless over a small or large geographic areas. A simple network may be connecting only two computers or one computer and a hardware. A complex network may be connecting millions of computers and devices.
- 4. Communication channels IN WIRED COMMUNICATION In wired communication we use the following channels. It means connecting with the cables. 1. Twisted pair cable one or more twisted wires bundled together. made of copper. 2. Co-axial cable consists of single copper wires surrounded by three layers of insulating and metal materials. typically used for cable TV. 3. Optical fibre cable strands of glass or plastic used to transmit light. very high capacity, low noise, small size.
- 5. IN WIRELESS COMMUNICATION 1. Infrared transmission infrared wireless transmission sends data signals using infrared light waves at a frequency too low for human eyes. 2. Bluetooth using radio frequency to transmit data to other devices. 3. Wi-Fi Exchange data wirelessly using radio waves over a computer network.
- 6. Types of network The geographic area covered by the computer decides its types. Thus based on geographic coverage networks are classified in the following manner. There are mainly three types of networks. WAN (Wide Area Network) MAN (Metropolitan Area Network) LAN (Local Area Network)
- 7. Wide Area Network WAN is computer system that spans a relatively large geographical areas. This network uses telephone lines, satellite communication etc. The largest WAN in existence is the internet.
- 8. Metropolitan Area Network The term metropolitan refers to a city. This network coverage a large geographic area limited with in the city or a town. It is a computer network usually spanning a campus or a city which typically connects a few local area networks. Eg: cable TV network spread over a city can be termed as MAN.
- 9. Local Area Networks LAN is capable of interconnecting a large number of computer and other peripheral devices within a limited geographic area. Eg: network in an office, internet cafe etc. ELEMENTS OF LAN 1. server 2. work station 3. network interface unit 4. communication channels
- 10. LAN Topologies The computers can be installed according to the branches. There are variety of topologies used in a local area network. These are as follows Star topology Bus topology Ring topology Tree topology
- 11. INTRANET Intranet is an application of internet to a closed networking system. It is a cost efficient way to use internet related services. EXTRANET Extranet is that network which links some of the intranet of a company with its partners, customers etc. Who can access selected intranet websites and companies database.