Communication Networks for Digital Information

Considerable advance has been made in the automation of clerical work over the last ten years, and the movement continues unabated. There is thus an ever-increasing need for means of telecommunication suitable for the exchange of information between computers and remote input and output equipment (i.e. data transmission). As soon as large organizations, or organizations spread over a large geographic area, adopt automation of clerical work, a need arises for a system comprising one or more computers which have to be linked to numerous sets of input and output equipment. This necessitates a telecommunication network for digital information, and this network must be perfectly matched to, and form an integral whole with, the system. An excellent example of such an arrangement is an airline space reservation system. This system is examined in detail, and its operational and technical requirements are discussed, as well as the means of realizing them. Particular attention is paid to the question of reliability, speed and efficiency, and it is shown that these three factors are closely interrelated. When traffic is heavily concentrated, it will be necessary to employ high signalling speeds, though these will not be economically justified where traffic is light.