Multi-layer LEO Satellite Constellation Design for Seamless Global Coverage

In this paper, we investigate the traffic-sensitive multi-layer low Earth orbit (LEO) satellite-terrestrial network. Massive terrestrial user access to the core network is realized via the backhaul supported by multi-layer LEO satellites. The ultra-dense satellite topology enables a promising solution for the high-capacity backhaul data transmission for terrestrial users. Jointly considering the backhaul capacity requirement and traffic dynamics of terrestrial satellite terminals, we analyze their average backhaul capacity using both stochastic geometry and queueing theory. Aiming to minimize the total required satellite number for fulfilling the backhaul capacity and seamless global coverage requirements, we propose a multi-layer LEO satellite constellation deployment scheme considering the satellite mobility. Simulation results verify the backhaul capacity analysis and the advantage of multi-layer constellation for saving satellites. The optimized multi-layer LEO satellite constellation with any coverage requirement and traffic rate is presented.