Cooperative Caching in Satellite-Terrestrial Integrated Networks: A Region Features aware Approach

Abstract

As an essential part of the next-generation communication system, the satellite-terrestrial integrated network (STIN) can provide Internet access and content delivery services for terrestrial users in remote areas. However, more and more content-related traffic requested by users poses challenges to the transmission capability of STINs. Thus, how to provide high-quality content delivery service has become an urgent problem in STINs. In this paper, we leverage the caching capabilities of low earth orbit (LEO) satellites and devise a cooperative caching scheme to achieve low latency and bandwidth-efficient content delivery service. First, considering users' diverse request preferences in different geographical locations, we propose a region features prediction model based on the ridge regression method to update users' preference information. Second, according to the similarity of predicted region features, terrestrial regions covered by LEO satellites are further divided into multiple cooperative areas. Third, we propose a cooperative caching algorithm based on game theory to achieve distributed caching decisions in every single cooperative area. By implementing this cooperative caching scheme, terrestrial users can acquire high-quality content delivery service through STINs. Extensive evaluations show that the proposed caching scheme can significantly reduce content delivery delay while saving valuable bandwidth resources compared with the existing ones.