A novel multiple-channels scheduling algorithm based on timeslot optimization in the advanced orbiting systems

Multiple-channels data from satellite and unmanned aerial vehicles images have gained much attention. An advanced approach used in the advanced orbiting systems is to divide the space channels into multiple-channels, called virtual channels (VC), which are scheduled according to a special mechanism achieved through the feature learning of on-satellite models. Considering that the performance of the existing multiple-channels scheduling algorithm is not good enough and the buffer size is rarely considered, a novel multiple-channels scheduling algorithm based on timeslot optimization is presented and its performance under the finite buffer size is also studied. Firstly, an optimized timeslot assignment method is designed based on both the ratio of synchronous frames arrival rate to asynchronous frames arrival rate and the allowable maximum time delay of synchronous VC frames. Secondly, the periodical polling scheduling strategy is adopted to schedule the synchronous VCs at the synchronous timeslots. If there are no corresponding synchronous VC frames in a synchronous timeslot, another synchronous or asynchronous frame will be selected and scheduled according to the scheduling mechanism. Thirdly, a dynamic scheduling strategy based on the transmission urgency of VC is adopted to schedule the asynchronous VCs at the asynchronous timeslots. The research results show that the performance of the proposed algorithm is much better than that of the other scheduling algorithms in terms of the time delay and channel utilization rate. The proposed multiple-channels scheduling algorithm for the finite buffer size is extensively studied and the upper bound of rate of frame-lost timeslots of each asynchronous VC is concluded.