Analysis of Safety-Critical Communication Protocols for On-Premise SIL4 Cloud in Railways

• Published in: Reliability, Safety, and Security of Railway Systems. Modelling, Analysis, Verification, and Certification pp. 211 - 220
• Main Authors: Rother, Benjamin, Golatowski, Frank, Ansar, Zeeshan, Kuzhiyelil, Don, Resch, Stefan, Hametner, Reinhard, Pathak, Prashant
• Format: Book Chapter
• Language: English
• Published: Cham Springer International Publishing
• Series: Lecture Notes in Computer Science
• Subjects: Protocols; Railway; Safe computing platform; Safety; SIL4; SIL4 cloud
• ISBN: 3031058135; 9783031058134
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-031-05814-1_15

In this paper, we address the question of how SIL4 railway applications within on-premise cloud environments can communicate safely with internal and external systems. The EN 50159 standard is the railway standard applicable for safety-related communication. For IT/OT Security IEC 62443 can be considered. Most standardized protocols developed according to EN 50159 are peer-to-peer protocols involving two communication partners. To leverage the cloud environment, contemporary applications of other domains use a different communication scheme, namely publish-subscribe, to connect internal and external components and enable scalability. Based on this challenge, the goal of this paper is to investigate emerging communication protocols from different domains and their suitability for the railway system. We will first determine the requirements for the railway communication infrastructure and applications executed in a SIL4 cloud, i.e., an environment provided by on-premise data centers utilizing technologies such as virtualization and with other cloud-like features, such as scalability and flexible usage of resources. Furthermore, a brief comparison of the potential application-layer communication protocols from industrial domains with railway-specific safety-critical protocols will be presented. Finally, we will present a system architecture that demonstrates how safe communication can be realized by middleware protocols such as DDS or OPC UA and how they fulfill the previously established requirements for the railway system.