A Dynamic Multicast Tree Selection Algorithm in LEO Satellite Networks

Satellite networks are a promising way to provide ubiquitous access to network service. However, due to the mobility of satellites, the traditional routing scheme cannot be adapted to the constellation directly. This paper studies the challenge of multicast routing on satellite networks. The mobility of satellites makes the serving satellites of ground users change with time. When performing a multicast on the constellation, the changing of serving satellites leads to many link handover control messages. To minimize the control message overhead is NP-hard. Therefore, a dynamic programming-based algorithm called Dynamic Multicast Tree Selection (DMTS) is proposed to find the sub-optimal result with polynomial time complexity. Besides, we proposed a tree generation algorithm called LMBBSP with DMTS to avoid link congestion in unbalanced network load. The simulation results show that our proposed schemes outperform the baselines with link handover and request rejection rate.