Architekturkonzept und Designaspekteeiner signaltechnisch nichtsicheren Kommunikationsplattformfür sicherheitsrelevante Bahnanwendungen

Abstract

In this dissertation a design for a communication platform for distributed railway applications is presented. A strict separation of fail-safe and non-fail-safe functionalities and a decoupling to the greatest possible extent of communication functions from the railway applications permit the use of standardised communication infrastructures and technologies from the field of distributed communications. Through the service integration of the preceding gateway functionality the utilisation of the limited transmission capacity of the existing communication infrastructure can be considerably increased.The stringent demands made on the reliability of the overall system are satisfied by the use of special failure-tolerant link protocols and the creation of redundant gateway clusters. The advantage of using the special link protocols lies in the reduced complexity on the fail-safe signalling&safety side. For the implementation of the switching and protocol functionalities of the preceding gateway entity, a framework running in user space with special resources was created within the communication platform.For the validation of the communication platform the following hardware-in-the-loop strategy was applied:Communication scenarios are stimulated by a test environment and tested automatically. Besides the verification of the correctness of the exchanged data and consistency of the protocol primitives received at the user interface of the unit under test, the transfers can also be observed at the interfaces between the protocol layers. In order to demonstrate conformity, a concept was developed based on a layer-wise analysis of the protocol data stream of the communication stack to be tested.