200510 – Aitken – Public Carrier Communications Technologies and Strategies for Low Traffic Lines

Australian railways have very low traffic densities on long routes. On many lines the traffic density does not justify a railway owned communication system so public carriers are used for both fixed and mobile communication. There is nothing new about using public carrier services in such situations – both fixed and mobile services been used for many years with substantial success. Soon the majority of Australian freight and country passenger services will use public carrier services for mobile communication.

Public carriers do not set out to provide reliable communications infrastructure for safety critical systems. They set out to optimise the profitability of their infrastructure. Can a railway rely on such a system for its operation? We review some technical and operational considerations.

Australian railways have resolved some of the technical and operational issues creatively. The most significant of these systems are described, along with the particular requirements of off-train communications.