Research on satellite link allocation algorithm for Earth-Moon space information network

With ongoing advancements in space exploration and communication technology, the realization of an Earth-Moon space information network is gradually becoming a reality. One of the critical factors for efficient communication within this network is the allocation of satellite links. To optimize the communication delay between Earth-Moon satellites, a dedicated Earth-Moon satellite link allocation algorithm has been developed using NSGA-II (non-dominated sorting genetic algorithm II). To determine the most suitable crossover operator for this algorithm, three different operators were evaluated for their impact on communication delay within NSGA-II. We regard the links assignment in each slot as a general graph-matching problem. An initial distribution of satellite links is generated by using a depth-first search algorithm. Subsequently, NSGA-II is applied to optimize the overall satellite link sequence. The simulation scenes include five lunar satellite constellations and 24 MEO (medium earth orbit) satellites from Earth’s BeiDou constellation, and the simulation results show that our method can effectively solve the problem of link allocation. Notably, the sequential crossover method outperforms the single-point and two-point crossover methods in reducing communication delays between Earth and Moon satellites. This study provides both theoretical and technical support for the development of future Earth-Moon space information networks, ultimately enhancing the efficiency of space communications.