A New Analytical Approach to Evaluate the Critical-Event Probability Due to Wireless Communication Errors in Train Control Systems

Wireless communication links tend to be employed more and more in safety-critical railway applications. Their safe use in an advanced train control system (TCS) is an issue that is addressed in this paper by characterizing the TCS service interruption due to communication errors. More precisely, occurrence probabilities of single errors are first discussed. Then, we obtain probabilistic analytical expressions of several temporal conditions that lead to a TCS service interruption, here a train emergency braking (the critical event). The accuracy of this analytical approach is proved when the results are compared with those given by a simulation approach with a Petri net model. Additionally, as the use case related to the “trains' separation” is considered in this paper, an analytical evaluation process is proposed to discuss the tolerated time margins that can be fixed to limit the critical-event occurrence probability due to the wireless communication errors.