Delay-Optimized Backpressure Algorithm for Load Balancing in LEO Satellite Networks

Low Earth Orbit (LEO) satellite networks, with low latency, wide coverage, and high scalability, are key to space-air-ground integrated networks. Yet they face load imbalance due to growing global communication demand and uneven terrestrial services. In this work, a Delay-Optimized Backpressure (DOBP) routing algorithm is proposed, which integrates queue backlog and path residual delay into link weight, optimizes delay via dynamic bandwidth allocation, and avoids flow starvation with a minimum load factor. Lyapunov function-based analysis confirms its throughput optimality. Simulations show DOBP outperforms existing methods in higher throughput, lower end-to-end delay, better load balancing, and stronger stability for LEO networks.