Dynamic Scheduling for Emergency Tasks in Space Data Relay Network

As a platform for data transmission, space data relay network (SDRN), which has high coverage and continuous communications, provides data relay services for the spacecrafts and satellites by allocating antenna resource. However, the diversity between emergency tasks and common tasks for antenna requirements may result in the conflicts of resource occupation. This leads to the loss of emergency information and the low scheduling efficiency. In this paper, a real-time dynamic scheduling (RTDS) scheme is proposed to ensure the transmission of emergency tasks and improve the scheduling efficiency by scheduling sequence adjustment and task management. Firstly, the relative SDRN system models are given and a dynamic scheduling mechanism is designed to deal with the disturbance factors during the scheduling process. Then, based on the dynamic scheduling mechanism, the RTDS scheme is implemented in three stages, which include initial scheduling, dynamic scheduling for emergency tasks, and final scheduling. The simulation results demonstrate that the proposed RTDS scheme can guarantee the timely transmission of emergency tasks and enhance the scheduling efficiency compared with the existing scheduling algorithms.