Research on Cache Placement Optimization and Popularity-Based Content Prefetching Strategy in LEO Satellite Networks

Low Earth Orbit (LEO) satellite networks, due to their wide coverage and low latency, have shown great potential in global content distribution. However, the limited caching resources and increasing user demands present significant challenges for the optimization of content caching strategies. Named Data Networking (NDN), by decoupling content from addresses, enables more efficient use of the caching resources in satellite nodes, thereby reducing transmission latency. In this work, we first provide the optimized placement of cache nodes in LEO satellite networks and an axis-based cache placement strategy is proposed. Furthermore, a dynamic prefetching strategy based on content popularity is introduced, integrating the calculation of the Value of Popularity (VoP) matrix to optimize content selection for caching. Simulation results demonstrate that, compared to the classical LCE caching strategy, the proposed strategy significantly reduces the average path length, decreases content transmission latency by approximately 10%, and enhances the cache hit rate by approximately 12%.