Downlink aware data scheduling with delay guarantees in resource-limited leo satellite networks

In recent years, data scheduling in satellite networks has drawn much attention. The nodes in the satellite network change dynamically, and there is no continuous connectivity between nodes. Due to the intermittent connection between satellites, data transmission is based on a storage-carry-forward mode. In such a network, it will inevitably result in transmission delay. It is challenging to schedule a large amount of observation data with delay guarantees in resource-limited satellite networks. In this paper, we propose a downlink aware data scheduling algorithm based on a decomposition strategy of rolling horizon mechanism. The data flows with deadlines are allocated to ground stations orderly through feasible routes during each sliding horizon. Considering the issues of time-varying node centrality and downlink capacity, a link metric is provided to solve the problem of downlink contact conflict. Then a heuristic routing algorithm is exploited to design inter-satellite link contact. Further simulation results demonstrate the effectiveness of the proposed algorithms in network profit improvement while ensuring the transmission delay demand.