Data communication and networking

Data communication is an essential task in a computer. Some channels are employed to transmit digital signals over computer networks. The efficiency of the transmission channel depends upon the characteristics of the channel. Different channels employed nowadays are two wire open lines, coaxial cables, twisted-pair cables and fiber optic cables. Two wire open line is a simple transmission channel with two open wire lines. Here some pairs of metallic wires made up of copper or aluminium that are insulated from each other are used. Three different configurations of two wire open lines are simple wire pair, flat ribbon connector and multicore cable. Normally, two wire open lines are used for the transmission of data in short distances. Coaxial cable channel provides higher speed over longer distance. Coaxial cable consists of four parts namely, core, insulator, conductor and protective sheath. The two types of coaxial cables are baseband and broadband. Twisted-pair cable consists of a pair of insulated copper wires which are twisted together in helical form. Two types of twisted-pair cables are shielded and unshielded. Telephone networks use such cables. Fiber optic cable consists of a core, cladding and a jacket. Long distance transmission is easily possible with fiber optic cables. But they are expensive. Highly skilled man power required for maintenance and installation of fiber optic cables.