Worst-Case Timing Analysis of AFDX Networks With Multiple TSN/BLS Shapers

This paper addresses the problem of worst-case timing analysis of extended Avionics Full Duplex Switched Ethernet (AFDX) networks, incorporating Time-Sensitive Networking (TSN) shapers called Burst Limiting Shapers (BLS), to enable the interconnection of different avionics domains with mixed-criticality levels, e.g., current AFDX traffic, Flight Control and In-Flight Entertainment. Conducting such an analysis is a challenging issue when considering multiple BLS-shaped traffic classes, due to the sophisticated inter-dependencies between the different shapers sharing the same output capacity. We tackle this problem through extending the applicability domain of our previous work for computing maximum delay bounds using Network Calculus and considering only one BLS class, called Continuous Credit-based Approach (CCbA), to handle multiple TSN/BLS classes. We provide further insights into the sensitivity and tightness issues of worst-case delay bounds yielded with the Generalized CCbA (GCCbA). Our assessments show that the tightness ratio is up to 85%, with reference to Achievable Worst-Case delays. We also show the improvements against recent state-of-the-art approaches in terms of tightness and complexity, where the computation time is up to 10
⁵
faster. Finally, we evaluate the efficiency of GCCbA for realistic avionics case studies, e.g., adding A350 flight control traffic to the AFDX. Results show the good applicability of GCCbA and confirm the efficiency of the extended AFDX, which decreases the delay bounds of the existing AFDX traffic by up to 49.9%, in comparison with the current AFDX standard.