Evaluating Network Protocols for the Next Generation of Swiss Rail Vehicles

The task

Communication between all computer-controlled train components plays a key role in modernising rail transport. This raises the question of which bus system and which network protocol are suited to the CCS (Command Control and Signalling) system of future vehicles.

This question was to be answered as part of the smartrail 4.0 programme, a joint industry initiative of the Swiss railway companies SBB, BLS, SOB, RhB, TPF and VöV. The goal was to develop solutions for modernising rail operations.

As a recognised expert in the Train Communication Network (TCN) standards, a co-developer of TRDP (Train Real Time Data Protocol) and a development partner in the Shift2RAIL and Safe4RAIL initiatives, NewTec was commissioned to evaluate every candidate protocol.

The solution

The NewTec experts began by analysing the requirements for the vehicle bus (UVCCB, Universal Vital Control and Command Bus). After compiling the existing open network protocols, they evaluated the protocols and their topology. In doing so, they paid particular attention to the requirements of the European OCORA initiative (Open CCS On-board Reference Architecture).

It quickly became clear that three protocols (MVB, CANopen, Profibus) did not meet the requirements of the UVCCB. The remaining protocols were put through their paces, with the evaluation covering APIs, transmission safety, TCMS compatibility, TCN integration and development support, among other aspects. Two scenarios were played out. In the first, the UVCCB was treated as a physically self-contained system separate from the TCN, with access to the TCMS only via a physical gateway. The second scenario examined the option of direct integration into the next-generation TCN. Here a physical gateway would no longer be needed, but closer alignment with the network protocols would be required.

The results of the extensive evaluation pointed to using the Functional Distribution Framework (FDF), developed as part of CONNECTA and Safe4RAIL/Shift2RAIL and based on the TRDP communication protocol. Since FDF development was not yet complete at the time of the study, the NewTec experts recommended working together with CONNECTA.
The study can be downloaded from the smartrail 4.0 website (“UVCCB Study Bus Technologies”).