Link scheduling algorithm for constrained inter-satellite links

In small satellite networks, inter-satellite links (ISLs) are usually restricted. Each satellite is equipped with a limited number of transceivers and finite link storage capacity. Meanwhile, ISLs are established on demand, in either half-duplex or full-duplex mode. Under these restrictions, contention for transmission may occur when bursty traffic arrives, which will lead to network performance degradation. Considering these link characteristics, a link scheduling algorithm (GEMS) for multi-hop satellite networks is proposed in this paper. First, a constrained ISL model is built. Based on the model, time-effect of each link is defined and taken as a measurement of scheduling priority. Then, transmitters make sequential decisions according to the time-effect of each link in a greedy way. Simulation results show that compared with LQF, OPF and FQ scheduling, GEMS algorithm can guarantee higher throughput as well as lower delay in both constrained half-duplex links and full-duplex links.