关键词: 低轨卫星, 任务优先级, Dueling-DDQN, 算力路由, 时延优化

Abstract: To address the challenges of limited satellite–ground bandwidth and heterogeneous Quality of Service (QoS) requirements for tasks in Low Earth Orbit (LEO) satellite networks, an intelligent computing-aware routing method based on task priority is proposed. First, considering satellite computing and storage resources, a resource-constrained LEO satellite network model is constructed. The sun outage phenomenon is incorporated to dynamically evaluate link availability, thereby capturing the impact of space environmental disturbances on routing decisions. Second, a QoS classification and priority scheduling mechanism is established to characterize the heterogeneous requirements of tasks in terms of latency and packet loss rate. Subsequently, a joint optimization model for computation offloading and data transmission is formulated with the objective of minimizing the end-to-end average delay. Furthermore, the optimization problem is transformed into a Markov Decision Process to enable reinforcement learning-based solutions. A task-priority queue is introduced in task processing and data forwarding, and QoS constraints are incorporated to dynamically filter candidate action space. Meanwhile, task-priority weights are embedded into the reward function. Based on these designs, a Dueling Double Deep Q-Network (Dueling-DDQN)-based computing-aware routing decision algorithm is designed to achieve adaptive optimization of computation offloading and routing decisions. Simulation results demonstrate that, under a constellation of 288 satellites, the proposed method outperforms the Proximal Policy Optimization algorithm under different traffic loads. In particular, the average end-to-end delay is reduced by 4.28%–14.53%, and the task computing ratio is increased by 1.44%–2.89%. Moreover, the proposed method maintains good applicability across different constellation scales.

Key words: low earth orbit satellite, task priority, dueling-DDQN, computing-aware routing, delay optimization