A Heuristic Inter-Satellite Fault Tolerant Routing Mechanism Based on A-Star Algorithm

As inter-satellite networks grow, reliable routing is critical. However, it is still challenged by rapidly changing topology and propagation delay. Unlike Internet protocols, space solution requires different approaches because of long distance spans and large propagation delays of inter-satellite links (ISLs). We propose a fault-tolerant routing mechanism using a modified heuristic function based on A-Star algorithm to reduce search space and determine optimal paths faster. Simulations at various failure rates and network sizes demonstrate the efficiency of routing and stability of time cost at various path lengths. Our mechanism can find the sub-optimal path quickly regardless of size, minimizing route time and guaranteeing short path length. This shows promise for applying this mechanism to future mega-constellation routing.