Video switching technology advances in pace with future trends

Cable television (CATV), direct broadcast by satellite (DBS), and integrated services digital network (ISDN), are just a few examples of services on the horizon of widespread deployment. A common feature to all is the requirement for many separate channels to share the same transmission path usually in some form of time-division multiplexing. The resultant signal takes the form of a high bit-rate serial data flow. Switching devices are again stressed by the requirement to: mux/demux many channels to share a common transmission channel; route high data rate serial information under transmission; handle many parallel channels with minimum interaction prior to multiplexing, or after demultiplexing. The author examines the demands that these trends put on switching devices, reviews current and experimental technologies, and provides an insight into recent developments made in analogue switch process technology that lends itself to these wideband requirements