Cell Planning for High-Speed Train Operations in USA

Abstract

American railroads are planning to introduce the Positive Train Control System (PTC), a wireless communication system to control passenger and cargo train movements. By design PTC has two networks, the main control network that disseminates trackage rights and a wayside interface unit (WIU) network that beacons track status. One of the main constraints for adopting this system for high-speed trains is the limited bandwidth availability in USA, as higher speeds require more control packets to be communicated using the same radio channel. In this paper we propose an architecture that manages available bandwidth between control and WIU networks by considering the maximum number of trains that has to be simultaneously accommodated by a control point and allocate control channels for the uplink and downlink communication between trains and control points accordingly. The rest of the channels are assigned to wayside devices to minimize interference. Control point locations are decided so that there is proper communication between any train and a control point until the train is handed over to the next control point. The proposed architecture addresses the congestion management, power control and interference avoidance aspects of communication planning for high-speed rail operations. We demonstrate the applicability of our frequency management architecture for a hypothetical train intersection.