Performance Analysis of ITS-G5 for Dynamic Train Coupling Application

Abstract

Virtual coupling is a technique that shall allow trains driving on the same track with quasi-constant distance. This would also enable dynamical joining and splitting of trains while driving, thus providing the flexibility for railway operators to adapt to the changing traffic demands and to increase the throughput on todays overloaded lines. In order to realize dynamic train coupling, position and speed information must be reliably exchanged between trains with very low latency. Cooperative transportation systems (C-ITS), where road vehicles cooperate by exchanging messages, has received a lot of attention recently. In Europe, ITS-G5, which uses IEEE 802.11p technology for radio access, has been chosen for C-ITS. IEEE 802.11p offers the ability of direct communications between vehicles, i.e. ad hoc communications, for up to a few kilometers. The idea is to exploit IEEE 802.11p for dynamic train coupling. In this work, we discuss the use and the performance of IEEE 802.11p for Train-to-Train (T2T) communications along with Car-to-Car (C2C) communications. We address the influence of C2C communication on the performance of T2T communication and simple methods to reduce the interference from C2C users on T2T users.