Space OSPF: An Area Hierarchic Routing Protocol for Routers in Motion

[Abstract] The research presents a routing protocol for exchange of routing information among vastly spread routers in space which may also be in continuous motion. We call it Space OSPF. The proposed protocol uses trajectories of spacecrafts and supports calculation of approximated optimum path routing tables ahead of time or on-demand withstanding topological changes due to continuous motion. Since the trajectories of spacecrafts are either predictable (e.g., satellite constellation orbiting a planet), preset (e.g., Space Station), or set on demand (e.g., a space shuttle), the suggested routing protocol enables routers on board those spacecrafts to calculates the time intervals where spacecrafts are in direct view with each other and expected delay. Additionally, this protocol divides the routing domain (e.g., our solar system) into hierarchical routing areas. The hierarchical area provides necessary localization to efficiently and orderly distribute routing information throughout the vast space routing domain. The proposed protocol is suitable for building a space communication infrastructure and provides support for intermittent pathways. The paper presents the principal elements of this protocol along with its stability analysis.