Inter-satellite Routing Study for LEO Constellations Based on Orbit Prediction

In recent years, low-orbit satellite constellation technology has developed rapidly. Constellations consisting of hundreds of LEO satellites can achieve global coverage of signals and thus fast transmission of data between any two points worldwide. However, since LEO constellation is a periodically changing satellite network, it will be a major challenge to find out the communication route between two points in the dynamic network quickly. In this paper, the orbit coordinates of each satellite node in the constellation are predicted in the next one minute based on the orbit forecast using the two-body model, and then the trajectories of the satellite nodes in this period are fitted with the satellite link model to construct the network topology of the whole LEO constellation in this one minute. Finally, this paper introduces the time aggregation graph model and designs the shortest delay path on discrete time aggregation graph (SP-DTAG), which is used to find the shortest delay path in the network topology of LEO constellation. Finally, we realize the point-to-point real-time communication in the satellite network. Finally, the simulations are carried out in terms of end-to-end delay and packet loss rate of the network, and the simulation results show that the SP-DTAG algorithm involved in this paper has a good performance in terms of end-to-end delay and network packet loss rate of the LEO constellation network.