Inter-layer Link Design for Resource-Constrained Double-Layered Satellite Network

Due to the relative motion of low-orbit satellites and high-orbit satellites, the inter-layer links (ILL) of double-layered satellite networks (DLSN) need to be dynamically switched, thus causing the satellite network topology changing dynamically. Traditional inter-layer link establishment strategy is low-orbit-centric which assumes that the number of ILLs equipped on high-orbit satellite is not limited. However, actual DLSNs are generally resourceconstrained, such as weight and power. Thus the number of ILLs can be equipped on one satellite is limited. Therefore, traditional ILL establishment strategy is hard to apply in practice. In this paper, we first propose an ILL establishment strategy which is high-orbit-centric. We assume that high-orbit satellites have only one ILL and use this as a precondition to establish ILL. Then, the system snapshot performances of two ILL establishment strategies under two typical DLSNs constellation configurations, which are LEO/MEO and IGSO/MEO, are simulated and analyzed. Finally, since ILL establishment strategy which is high-orbit-centric can make the ILLs of some low-orbit satellites idle for some time, we point out that further research should be carried out about how to effectively use low-orbit satellite ILLs.