world-wide, networks. At each extremity of the network is a terminal device, or even a large computer, which can send jobs over the wire to the central computer at the hub of the network. The central computer performs the computation or data processing and sends the results over the wire to any terminal in the network for printing. Some computer networks provide a service called time sharing. This is a technique in which software shifts the computer from one task to the another with such timing that it appears to each user at a terminal that he has exclusive use of the computer. b) Telecommunications Certain telecommunication methods have become standard in the telecommunications industry as a whole, because if two devices use different standards they are unable to communicate properly. Standards are developed in two ways: (1) the method is so widely used that it comes to dominate; (2) the method is published by a standard-setting organisation. The most important organisation in this respect is the International Telecommunication Union, a specialised agency of the United Nations, and one of its operational entities, the International Telegraph and Telephone Consultative Committee (CCITT). Other organizations in the area of standards are the American National Standards Institute, the Institute of Electrical Engineers, and the Electronic Industries Association. One of the goals of these organizations is the full realisation of the Integrated Services Digital Network (ISDN), which is projected to be capable of transmitting through a variety of media and at very high speeds both voice and non-voice data around the world in digital form. Other developments in the industry are aimed at increasing the speed at which data can be transmitted. Improvements are being made continually in modems and in the communications networks. Some public data networks support transmission of 56,000 bits per second (bps), and modems for home use are capable of ...
