Secure Communications Based Train Control (CBTC) Operations

Abstract

Communications Based Train Control (CBTC) provides positive train separation, over speed protection, and protection for roadway workers. Current system designs do not include trust management systems to provide support for security, rendering CBTC communications vulnerable to malactors. Traditional train control methods and the architecture of CBTC systems are studied to determine specific vulnerabilities of CBTC systems and the associated system security requirements. The security requirement are then used to derive an appropriate trust management system. Existing work on safe cross domain dispatch operations has not considered the impact of these trust management systems on allowable traffic delays and system velocity or related them to train dynamics. A relationship between train dynamics and trust management delay is presented to allow engineering estimates of the practicallity of potential trust management systems to support rail operations while preventing collsions. An algorithm for the safe and secure scheduling of trains through the interchange point between is provided. The algorithm supports positive train separation under a worst-case traffic scenario, allowing for safe and secure scheduling while reducing traffic delays. The approach presented is illustrated by an example, and is independent of the specific security management, CBTC, and dispatch systems.