Design of Mega-Constellations for Global Uniform Coverage with Inter-Satellite Links

Abstract

Constellation configuration design is a prerequisite and critical step in the construction of a mega-constellation system in low Earth orbit. However, the huge number of satellites and the intricate changes in relative positions among them make the configuration design the most challenging part. In this paper, we propose a configuration design scheme for mega-constellations considering collision-avoidance constraints with the objective of uniform global coverage. In this design scheme, the constellation is made up of multiple Walker constellations with the same orbital altitude and different orbital inclination. Moreover, the analytical expression for the minimum distance between any two satellites in the same orbital altitude is derived, and the constellation internal collision-avoidance constraint is established accordingly. Finally, a permanent inter-satellite link design scheme without dynamic reconstruction is presented based on the mega-constellation configuration. Simulation results show that the mega-constellation design scheme introduced in this paper can achieve relatively uniform global coverage (its N Asset Coverage ranges from 18 to 25). The mixed Walker constellation is capable of providing a greater number of N Asset Coverage for most of the world than the Walker constellation of the same satellite order of magnitude. In addition, the inter-satellite link scheme designed in this paper can ensure continuous and stable communication between any satellite nodes.

When LEO Mega-Constellations Meet New Radio: A Holistic Performance Evaluation Framework

“…Nevertheless, the envisioned KPI framework cannot fully capture the constellation capability for NR enabled LMCSNs. For instance, the number of serviceable satellites at a specific location can vary as satellites move over time [21]. This phenomenon should be properly accounted by a constellation related KPI to exhibit the constellation coverage performance.…”

“…• N-asset coverage: the number of simultaneously serviceable satellites per geographic area wherein the received satellite signal quality is above a predefined threshold, e.g., the perceived SNR at a target SC from each of the N satellites is better than a predetermined threshold. The KPI is introduced to characterize the multi-fold constellation coverage performance for a LMCSN [21]. • Area traffic capacity: the total traffic throughput served per geographic area.…”

Autonomous Orbital Slot Maintenance with Impulsive Maneuvers and Reinforcement Learning

“…A recent research thrust is the design of low-Earth orbit constellations that can provide near-global coverage and would be applicable to a wide variety of missions such as terrestrial communications or remote sensing [1,2]. In such constellations, satellites are assumed to follow prescribed trajectories that are designed to avoid inter-satellite collisions while maximizing the capacity of different orbits.…”