Radio based railway signaling and traffic control system

Abstract

A railway signaling and traffic control system which minimizes the wayside equipment and eliminates the pole lines which carry power and signals along the right-of-way using instead the radio channel between the trains and the central office. Each train communicates with devices, such as passive beacons, which provide zone boundary messages. These devices provide secure messages to a control unit containing a microprocessor which responds to zone boundary messages and provides location information to the central office via radio when the train enters and leaves each zone. The central office has an input and communication processor and a vital processor. The vital processor converts route requests and the zone occupancy messages which are received by the input and communications processor into messages representing the signal aspects (the maximum speed at which the train can proceed), not only for the zone currently occupied, but also for the zone next ahead. The train control unit stores both aspects and displays the aspect for the currently occupied zone. When the train crosses a zone boundary and enters the next zone the new aspect is displayed. The distance for which the aspect remains valid is restricted by the zone boundary beacons and cross-checked by the locomotive odometer. Train stops, which were previously used to limit the distance an aspect is valid, are avoided thereby simplifying the signaling system.