Using Front End Processors in Traffic Control Data Transmission Systems

The present London traffic control system has been in operation for over 20 years. There are basically two different systems in operation: Urban Traffic Control (UTC), Remote Monitoring (RM), and some other smaller systems. The principal system is the UTC which controls some 2000 traffic signals in London. There are three Compaq Alpha based mini-computers which are connected to the Data Transmission Equipment (DTX) using Front End Processor (FEP) systems. This paper discusses the general properties of FEP based traffic control systems, giving the traffic control system in London as an example working system.