Reliability of the IP Network-based Signal Control System and the Integrated Logical Controller

East Japan Railway Company developed the IP Networkbased Signal Control System, which was introduced into service in February 2007, with an innovative change of the control techniques for wayside signaling devices from power control through conventional metallic cables to digital information control through an optical network. This system is intended to improve the quality of construction of signaling devices by reducing the wiring work that is required for a large number of metallic cables and simplifying the operation tests. In this system, reliability is improved by using the duplex transmission lines, including the optical network. In this paper, we describe reliability of the IP Network-based Signal Control System and discuss application to the Integrated Logical Controller that is currently under development.