Optical Communication–Based Train Control Architecture

Modern railway signaling systems require continuous, high-reliability communication between onboard train controllers and ground-side control infrastructure to ensure safe, efficient, and high-capacity operations. Conventional signaling and Communication-Based Train Control (CBTC) systems rely heavily on radio-frequency communication and extensive trackside hardware, resulting in bandwidth constraints, electromagnetic interference susceptibility, and high infrastructure and maintenance costs. This report presents a CBTC signaling architecture based on optical (light-based) communication between trains and wayside equipment. The proposed system employs laser or high-power LED transmitters and receivers to establish bidirectional, high-data-rate communication links between onboard computers and distributed access points along the track. Redundant communication paths are implemented using dual (front and rear) onboard receivers and parallel “red” and “blue” infrastructure networks to ensure fault tolerance and continuous availability. The architecture integrates access points, beacon-based trackbed communication, local and central switching networks, and onboard control units to support moving-block train control, precise train localization, and real-time movement authority updates. By shifting signaling communication from radio to optical links, the system enhances data throughput, security, and robustness while reducing dependency on spectrum-limited wireless technologies. The proposed light-communication CBTC framework offers a scalable and resilient alternative to conventional signaling systems, particularly suited for high-density and high-speed rail networks where reliability, redundancy, and precise train control are critical.