The Capacity of LEO Satellite Constellations With Link Failures

In this study, we model the LEO satellite constellation with link failures as the Δ -random regular graph, where Δ : (≥q 4) is the number of antennas per satellite, i.e, each satellite can establish at most Δ inter-satellite links (ISLs). It is found that the critical temporary failure probability at which the constellation structure collapses is pc(Δ) = Δ -2Δ -1. We show that the capacity upper bound is proportional to Δ γ (p)L(α,D) when p< pc(Δ). L(α,D) is the average hop distance without link failures under traffic decay factor α in (0,1). γ (p)< is the hop stretch factor measuring the extra hops to overcome link failures. D is the diameter of constellations. When p to 0 and α to 1 , our results degenerate to the capacity upper bound under all-to-all traffic model. We also show that the capacity upper bound of one-to-many traffic is sm times that of many-to-one, where m is the number of source or destination satellites. This is because, in one-to-many traffic model, the source satellite transmits identical data packets to the destination satellites. To achieve the capacity upper bound, we propose the distributed shortest-hop routing framework based on local link states (DSR-L), which uses prior geometric knowledge of the constellation structure. These results can provide effective guidance for resilience strategies regarding redundant satellites and ISL configurations.