A Review of Electronic Switching Developments in the United Kingdom

Electronic telephone switching developments in the United Kingdom have included comprehensive studies and trials of both Space and Time Division Systems by the Joint Electronic Research Committee. The time-division-multiplex development program led to the conclusion, in 1963, that pulse amplitude modulation systems would not be economic, for some years at least, and would pose complex transmission and maintenance problems. The space division development program led to the conclusion that reed-relay systems would offer all the advantages looked for in electronic switching systems. Two 200-line units are already giving good public service, and a 3000-line unit is being installed. Further orders have been placed, and the British Post Office is planning a steady build-up of orders over the next few years.