Bounding End-to-End Delay for Real-Time Environmental Monitoring in Avionic Systems

Timing guarantees and predictive early analysis are essential considerations for the design of reliable and verified real-time avionics systems. In this paper, we consider an environmental monitoring avionic system, which allows physical circumstances to be visually monitored continuously in real-time. We analyze timing aspects on the partitions of front-end and back-end nodes, and intermediate node which interconnects those systems. On the end nodes, we use ASIIST to evaluate the worst-case delay for PCI bus analysis. And then, we propose a novel real-time switching algorithm which ensures the delay bound on the intermediate node. Finally, we derive the end-to-end delay on the whole system accurately and show how it can be bounded. A predictive analysis on the worst-case end-to-end delay of a system, before deployment, can result in more reliable and well-verified environmental monitoring systems. We also expect this to reduce the cost of designing and implementing environmental monitoring avionic systems.