Physics-Based Optimization of Access Point Placement for Train Communication Systems

Communication-based train-control (CBTC) systems are aimed at replacing conventional rail signaling with train control enabled by wireless communication between the train and a network of access points. The position of the access points has a significant impact on the performance of such a system. This paper presents an efficient optimization framework of access point placement through combining a site-specific electromagnetic simulator and an optimization algorithm. The aim of this approach is to select an optimal distribution of access points in order to maximize the coverage of the system. To that end, radio-wave propagation is modeled with the vector parabolic equation method, while the optimization of the access point location is pursued via the robust and well-convergent Hooke and Jeeves algorithm. Practical constraints and engineering considerations associated with the deployment of CBTC systems are taken into account. Numerical results are compared with experimental measurements in an actual CBTC deployment site, demonstrating the validity and usefulness of the proposed methodology.