Digital transmission of multiplexed video and audio signals at 140 Mbit/s over an experimental optical-fibre transmission system

During 1977, BBC Research Department was invited to participate in field trials of an experimental optical-fiber digital transmission system installed between the Post Office telephone exchanges at Hitchin and Stevenage. BBC equipment was specially adapted for these trials to provide multiplexed digital video and audio at 140 Mbit/s and to decode these signals after transmission. High-quality audio and video signals were sent between Hitchin and Stevenage, a total distance of some 18 kilometers for the return path, over a period of one month during which time a number of tests were conducted. Brief description of the equipment and tests are reported.