A revised trajectory approach for the worst-case delay analysis of an AFDX network

AFDX (Avionics Full-Duplex Switched Ethernet) standardized as ARINC 664 is a major upgrade for safety-critical applications in avionics systems. Worst-case delay analysis of all the flows transmitted on the AFDX network is mandatory for certification reasons. Different approaches have been proposed for end-to-end (ETE) delay upper bound, such as network calculus and trajectory approach, but these methods still introduce some pessimism in the computations and overestimate the exact worst-case delay of the flows. In addition, the existing trajectory approaches may underestimate the exact worst-case delay of the flows for some corner cases. In this article, we revised the trajectory approach to make the flow analysis more accurate for the computation of the worst-case ETE delay. The results had been shown that the worst-case delay analysis of an AFDX network can be improved by using our revised trajectory approach.