Abstract
Recent advances in information and communications technology (ICT) have enabled the adoption of wireless communication techniques in all sectors for the transmission of information in all forms between any two points. Wireless communications and distributed computing have encouraged interest in the development of vehicle health monitoring (VHM) systems to reduce the maintenance and inspection requirements of railway systems while maintaining safety and reliability. Railway communication and signaling systems are used to monitor the railway infrastructure and operations in order to maintain reliability, safety, and security. This paper surveys existing wireless techniques used in the railway industry for both communications and signaling purposes and for safe and reliable monitoring.