DATA COMMUNICATION & NETWORKING

v Data Communication deals with the transmissionof digital data from one device to another. Data istransferred through a pathway called ascommunication channel which can be physical wireconnecting the devices or may be unguided medialike laser, microwave etc.

v A communication channel has a source oratransmitter at one side and a designation orreceiver at another side of the network. The sourceof data origination is single but there may bemultiple receivers. A communication channel is of 3types:· Simplex: In this, communication is unidirectionali.e. one of the two devices can transmit the dataand the other can only receive the data. For eg.Radio broadcasting, television broadcasting etc.· Half duplex: In this communication isbidirectional. Either of the devices can act astransmitter or receiver but only one device cantransmit the data at one time. For eg. Walkietalkie.· Full Duplex: Here also communication is in bothdirections and both the devices cansimultaneously transmit the data. For eg.Telephone conversation.v Different types of network are: LAN, MAN andWAN.v  LAN (local area network) is a group of computersand network devices connected together, usuallywithin the same building. By definition, theconnections must be high speed and relativelyinexpensive (e.g., token ring or Ethernet).v MAN (metropolitan area network) is a largernetwork that usually spans several buildings in thesame city or town.v  WAN (wide area network), in comparison to aMAN, is not restricted to a geographical location, although it might be confined within the bounds of astate or country. A WAN connects several LANs, andmay be limited to an enterprise (a corporation or anorganization) or accessible to the public. Thetechnology is high speed and relatively expensive.The Internet is an example of a worldwide publicWAN.

For more information on Networking devices stay tuned for next posts.