Logic Path Identified Hierarchical (LPIH) Routing for LEO Satellite Network

The mobility of LEO satellites renders the routing design highly challenging for a large-scale constellation. This paper proposes a Logic Path Identified Hierarchical (LPIH) routing to overcome the challenge. LPIH is an information-centric routing scheme capable of mitigating the routing dynamics in LEO satellite networks. The key idea of LPIH consists of constellation partition and logic path identification, which enable an efficient and reliable hierarchical routing. Specifically, LPIH partitions the constellation into multiple satellite groups and keeps the link state advertisement (LSA) updated within each satellite group. Moreover, LPIH uses a unique logic path identifier (PID) to represent multiple physical links between adjacent satellite groups, which will be used in the inter-group forwarding. This way, LPIH will deliver content according to the inter-group PIDs recorded by the request packet (i.e., the PID sequence). The packet forwarding within a group is based on the inner-group routing table. Overall, LPIH appropriately decouples the inner-group and inter-group routing, which stabilizes the routing dynamics and facilitates the efficiency of forwarding in large-scale LEO constellation. We compare the performance of LPIH to the traditional information-centric approach (i.e., NLSR) via packet-level simulation on OMNET++. Results show that LPIH reduces the messaging overhead by 64.37% and improves the packet delivery ratio by 16% compared to NLSR.