Cooperative Content Caching and Distribution for Satellite CDNs

Content distribution networks play a crucial role in the services provided by streaming applications, but current terrestrial CDNs have uneven coverage and poor performance in some remote and rural areas. Satellite communications have emerged as an effective way to address these issues. However, the satellite environment is highly dynamic, and how to reasonably deploy CDNs in the satellite constellation to realize efficient content caching and distribution is an urgent problem to be solved. To this end, this paper proposes a content caching and content distribution approach for satellite CDNs. The approach uses Lyapunov optimization, Gibbs sampling, and matching theory to control the traffic cost of satellite-cached content copies while reducing the content distribution latency. A cost-effective content cache deployment and distribution strategy is proposed for large low-orbiting satellite constellations operating at high speeds. Extensive simulation results show that the algorithm can quickly converge to favorable values compared to the reference algorithm, effectively reducing latency for end users while maintaining low deployment traffic costs.