Mixed-criticality systems based on time-triggered ethernet with multiple ring topologies

TTEthernet ensures a predictable timing with bounded latency and jitter based on time-triggered and rate-constrained messages. Fault-tolerance using redundant switches and multiple stars is supported to preserve the communication services despite the failure of individual physical links or switches. However, other communication topologies are required in order to achieve scalability to large-scale systems and to support mixed-criticality systems. This paper introduces multi-ring topologies with corresponding TTEthernet switches for large-scale mixed-criticality systems. The architecture supports redundant channels using heterogeneous paths for time-triggered and rate-constrained messages, where switches autonomously perform the duplication and deduplication of redundant messages. Differences with respect to latencies on the redundant paths are hidden to ensure an unchanged network timing in case of failures. The architecture and the proposed switches are evaluated using a simulation framework.