Data transmission arrangement

In long distance transmission of data between transmitting/receiving devices via a process intermediary unit wherein the transmission of data uses an existing public switched telephone network for transmitting data from an originating transmitting/receiving device to the process intermediary unit and from the process intermediary unit to a destined transmitting/receiving device, the improvement comprising said process intermediary unit including a number of local nodes which are interconnected by a digital data transmission network by means of which data, to be transmitted a long distance, received by the process intermediary unit at a local node, is transmitted to another appropriate local node, and wherein at least some of said data transmitting/receiving devices associated with the process intermediary unit each have a unique telephone number address which when used results in a telephone connection with said process intermediary unit with said telephone number address being recorded and used by the process intermediary unit to identify the receiving device for which the data is destined.

A plurality of data transmitting/receiving terminals, each terminal having a non-telephone actuation means which when actuated causes said data transmitting/receiving terminal to complete a telephone connection with a process intermediary unit by means of existing telephone networks, said process intermediary unit having a host of telephone number addresses which are assigned to uniquely identify each of said data transmitting/receiving terminals and when any of the telephone number addresses are used a telephone connection is made with the process intermediary unit,

• wherein said process intermediary unit upon receipt of a communication for a particular telephone number address transmits a non-telephone actuation signal which is received by a destined transmitting/receiving terminal identified by the telephone number address which actuates said destined transmitting/receiving terminal to effect a telephone connection with the process intermediary unit and by means of which data destined for the receiving terminal is transmitted thereto by the process intermediary unit.