Constellation Structure Design for LEO Mega-constellation with Optical Intersatellite Link

A new space race for low earth orbit (LEO) mega-constellation enabled internet services is imminent, with several commercial companies, e.g., SpaceX, Amazon, OneWeb, working forward to high speed LEO constellation with optical inter-satellite link (ISL). Grid-mesh topology is commonly utilized for LEO constellation, even if it is not the best topology. But constellation structure design, as a more fundamental work than topology design, has not been investigated thoroughly. For a given LEO mega-constellation with a fixed amount of satellite, this paper explores the impact of constellation structure on network performance by adjusting the number of orbital planes. Simulation results show that under the inclined walker-delta model, the optimal network performance in terms of average/maximum hops is achieved while the difference value between the number of orbital plane and satellites per orbital plane is minimal. In addition, link congestion under shortest path routing scheme is also optimized with the proposed mega-constellation structure.