This study investigates the performance of an innovative routing protocol inspired by the Unsplittable Multi-Commodity Flow (UMCF) problem. LEO routing schemes are often based on Shortest Path (SP) algorithms, the Floyd-Warshall algorithm is usually chosen to compute these network paths within the constellation and their end-toend latency. Instead of considering latency as a criterion, we seek to optimize the overall amount of IP traffic crossing the constellation. This criterion can be optimized by considering the Unsplittable Multi Commodity Flow problem associated with the system. To solve this problem, we use a heuristic algorithm based on randomized rounding that was shown to return solutions of good quality of the Unsplittable Multi Commodity Flow problem in the optimization literature. Using network simulation over Telesat constellation, we show this proposal significantly reduces the overall congestion level compared to the standard SP routing schemes.
AFDX is the standard switched Ethernet solution for the transmission of avionics flows. Today's AFDX deployments in commercial aircrafts are lightly loaded to ensure the determinism of control and command operations. Manufacturers envision to take advantage of the remaining AFDX bandwidth to transmit additional non avionics flows (video, audio, service). These flows must not compromise the in-time transmission of avionics ones: constraints on jitter at source end system and end-to-end latency have to be insured for each avionics flow. In this paper, we investigate the scheduling of avionics and additional flows, mainly at the end system level. We show that an event-triggered strategy is better than a time-triggered one for additional flows at source level, but it might compromise the jitter constraint of avionics flows and increase the end-to-end latency of additional ones. We consider two time-triggered scheduling strategies, i.e. an optimal one and a simpler one based on a heuristic. We show that the later one performs nearly as well as the former one and that, for both of them, the difference with an event-triggered strategy at source level is limited and can be statically bounded.
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