Abstract :
The provision of telecommunications is not an end in itself but a means of enabling business and social contacts to be made at a distance as nearly possibly as readily as if the people concerned were in the same room. Historically, telecommunications networks have chiefly been used for voice telephony. Over recent decades, this has been supplemented by telex and facsimile transmissions. However, the principal development that has occurred since the advent of computers in the middle of this century has been the transmission of data, at first over networks designed for voice telephony but increasingly over networks dedicated to data transmission. Now that transmission and switching are being digitised, the main emphasis in the near future is on the implementation of networks over which the transmission of voice, data, text and images can be integrated
