A semi-distributed routing algorithm for LEO satellite networks

Satellites play a major role in the development of global information infrastructure. Low Earth Orbit (LEO) satellites can provide wide-range networking with short round-trip delays, thus becoming increasingly important in global communications. However, developing a specialized, efficient and robust routing algorithm in LEO satellite networks is a challenge in both research and practice. For example, algorithms based on topology can find the shortest path but the complexity of time and space is high; some algorithms based on Datagram Routing Algorithm (DRA) have a high computation overhead; others based on Dynamic Source Routing (DSR) store all route information in datagram, which however negatively impacts routing efficiency and robustness. In this paper, we propose a Semi-Distributed Routing Algorithm (SDRA). In this algorithm, the path with minimum propagation delay is discovered using delicate information of two routing hops. This design can reduce computation overhead to at most 50% of that of DRA. We evaluated the propagation delay through both simulations and practical tests. The result shows the proposed algorithm is more efficient and robust than DRA.