Rethinking LEO constellations routing

This study investigates the unsplittable multicommodity flow (UMCF) as a routing algorithm for LEO constellations. Usually, LEO routing schemes enable the Floyd-Warshall algorithm (shortest path) to minimize the end-to-end latency of the flows crossing the constellation. We propose to solve the UMCF problem associated with the system as a solution for routing over LEO. We use a heuristic algorithm based on randomized rounding known in the optimization literature to efficiently solve the UMCF problem. Furthermore, we explore the impact of choosing the first/last hop before entering/exiting the constellation. Using network simulation over Telesat constellation, we show that UMCF maximizes the end-to-end links usage, providing better routing while minimizing the delay and the congestion level, which is an issue today over new megaconstellations. The study proposes a new routing method based on the unsplittable multicommodity flow (UMCF) for LEO satellite constellations that improves traffic flow compared to the standard method (Shortest Path). UMCF performs especially well when congestion occurs. Additionally, choosing the best entry and exit points for the constellation is important for optimal routing, and selecting the k-nearest satellites can be more effective than just the nearest one. image