Electronic terminal-exchange unit

An electronic terminal-exchange unit designed as part of a new system to supersede existing systems, to integrate economically with them in the transition period and to provide all the features of future networks, including substantially improved speech transmission, is described. The unit is suitable for speech, and low-speed analogue and digital data: more specifically, it will terminate, control and switch analogue signals over a bandwidth from d.c. to about 7kHz (incidentally providing amplification by which transmission in the network may be improved) and digital signals at 16000bit/s and higher with additional terminal equipment.