Logic Path Identified Hierarchical Routing for Large-Scale LEO Satellite Networks

Low earth orbit (LEO) constellations equipped with inter-satellite links (ISLs) have the potential to provide global Internet services. However, the mobility of LEO satellites renders the routing problem of large-scale constellations highly challenging. This paper proposes a Logic Path Identified Hierarchical (LPIH) routing to overcome the challenge. Specifically, LPIH partitions the constellation into multiple satellite groups and identifies the logic path between adjacent groups via the path identifier (PID). Accordingly, LPIH detects and disseminates ISL state changes within the group, achieving fast routing convergence with little overhead. Furthermore, LIPH decouples inner-group routing from inter-group routing based on the PID. The inter-group routing is information-centric and pull-based, which relies on the in-packet PID to specify the inter-group forwarding path. This improves the reliability of inter-group forwarding since a PID corresponds to multiple ISLs. The inner-group routing is host-centric and push-based, which relies on the in-packet PID to specify the inner-group destination. Such hierarchical content retrieval allows LPIH to harness the benefits of information-centric and host-centric routing. We develop a simulation platform for satellite networks based on OMNeT++ and conduct extensive packet-level experiments. The results show that LPIH increases the packet delivery ratio up to 105.3% compared to state-of-the-art routing mechanisms.