Network-Calculus-Based Multiregion Joint Routing Algorithm for Large-Scale LEO Satellite Networks

With the advantages of low delay, wide coverage, and high throughput, low-Earth-orbit (LEO) satellite networks hold significant potential for establishing globally interconnected networks. However, the large spatial scale of satellite networks leads to lagging link state perception. Moreover, the perception overhead significantly increases with the growing number of satellites. These characteristics have brought great challenges to the routing design of large-scale LEO satellite networks. To address the above challenges, we propose a multiregion joint routing (MRJR) algorithm based on network calculus (NC) theory to achieve low-delay transmission without relying on traditional state perception. First, a multiregion NC model is introduced to efficiently manage satellite networks and decouple the traffic transmission process. Then, we design the MRJR algorithm, which accurately derives link traffic backlogs to acquire real-time link congestion states, thereby calculating the lowest delay routing path. Additionally, an NC timeslot correction mechanism is proposed to ensure the accuracy of traffic backlog calculations. The simulation results demonstrate that the MRJR algorithm outperforms existing routing algorithms in terms of average delay, throughput, and packet loss.