We propose a formal timing analysis of an extension of the AFDX standard, incorporating the TSN BLS shaper, to homogenize the avionics communication architecture, and enable the interconnection of different avionics domains with mixed-criticality levels, e.g., current AFDX traffic, Flight Control and In-Flight Entertainment. Existing Network Calculus models are limited to three classes, but applications with heterogeneous traffic require additional classes. Hence, we propose to generalize an existing Network Calculus model to do a worst-case timing analysis of an architecture with multiple BLS on multi-hop networks, to infer real-time bounds. Then, we conduct the performance analysis of such a proposal. First we evaluate the model on a simple 3-classes single-hop network to assess the sensitivity and tightness of the model, and compare it to existing models (CPA and Network Calculus). Secondly, we study a realistic AFDX configuration with six classes and two BLS. Finally, we compute a real use-case to add A350 flight control traffic to the AFDX. Results show the good properties of the generalized Network Calculus model compared to the CPA model and the efficiency of the extended AFDX to noticeably enhance the medium priority level delay bounds, while respecting the higher priority level constraints, in comparison with the current AFDX standard.
In this paper, we model and analyse the timing performance of an extended AFDX standard, incorporating the Burst Limiting Shaper (BLS) proposed by the Time Sensitive Networking group. The extended AFDX will enable the interconnection of different avionics domains with mixed-criticality levels, e.g., current AFDX traffic, Flight Control and In-Flight Entertainment. First, we present the model and the worst-case timing analysis, using the Network Calculus framework, of such an extended AFDX to infer real-time guarantees. Secondly, we conduct its performance evaluation on a representative AFDX configuration. Results show the tightness of the proposed model, with reference to simulation results. Moreover, they confirm the efficiency of incorporating the BLS in the AFDX standard to noticeably enhance the medium priority level delay bounds, while respecting the higher priority level constraints, in comparison with the current AFDX standard.