Practical Experience Report: Implementation, Verification and Validation of a Safe and Secure Communication Protocol for the Railway Domain Different communication protocols are currently being used for the railway domain. However, most of these protocols rely on many interlacing mechanisms and safety codes which raise their complexity. Therefore, companies operating in the railway domain, guided by the Italian railway network manager, devised the Protocollo Vitale Standard, a light network protocol that stems from the Euroradio and RBCRBC (Radio Block Centre) protocols. In this paper we report our practical experience in the implementation of the Protocollo Vitale Standard in compliance with a CENELEC SIL4 safety target. The implementation of this protocol required assembling a Vu0026Vu0026S plan to specify all the Vu0026V activities that need to be carried out before, during and after the implementation of the protocol. Moreover, coding styles, standards and code quality metrics are defined, and crossxc2xadchecked at various stages of the implementation. To complete our work, we conducted tests and performance analyses on the source code, while currently we are devising an adequate safety case aiming at a future certification.

Design for Testability of ERMTS Applications The European Rail Traffic Management System (ERTMS) represents a class of embedded softwareintensive systems of systems for the management of the European rail traffic, in a scenario where interoperability between different European rail traffic infrastructures must be maintained. Due to the intrinsically safetycritical nature of ERTMS, software testing must meet the strict prescriptions imposed by the certification authorities, which often require the availability of the entire system. This potentially leads to perform the tests at a late stage of development, even though the best practices suggest that it would be more convenient to test the system incrementally since the early stages of development. This paper deals with the solution we devised to address this issue in a recent ERTMS project. We adopted a designfortestability pattern which purposely enhances the observability and the controllability of the software under test to make it testable at any stage of development, allowing the exploitation of system tests even during component and integration testing.