Multiple gateway placement in large-scale constellation networks with inter-satellite links

摘要

Multiple gateways are required in large satellite constellation networks (LSCNs) with inter-satellite links (ISLs), and their placement may greatly affect the system performance. Gateway placement can be optimized to achieve better network performance under the non-uniform ground demand distribution. This paper formulates a gateway placement optimization model for LSCN with ISLs, aiming at achieving an optimal overall performance including delay, traffic peak, and load balance. The constraints of potential gateway location, gateway-satellite connectivity, and max hop-count are considered. A genetic algorithm (GA)-based method is proposed to solve the integer optimization problem with the help of quasi-evenly distributed reference layout. A Starlink-like constellation with ISLs is adopted in the simulation. The simulation results show that the optimized layout has better performance than the reference layout. Additionally, the locations with high user demand or at the middle of ocean are preferred by gateways. The network performance is jointly influenced by gateway placement, demand distribution, constellation configuration, node, and link capacities. The abnormally high ISL hop-count is found in the south Indian Ocean, which is caused by constellation and ISL configuration.