A Novel Adaptive Data Prefetching Scheme in Satellite-ground Integrated Networks with Edge Caching

The satellite-ground integrated network has been proposed to be one of the key technologies in the next-generation wireless communication network. However, in the network with low orbit satellites (LEO) as relay nodes to serve the backhaul, both the wireless access links and the backhaul links are changing rapidly. In this paper, we propose to deploy the software-defined network and edge caching to extend the concept of content prefetch from users to networks, which compensates for the poor transmission conditions in the satellite-ground mobile network. Specifically, an optimization problem is proposed for the prefetching scheme based on the current and predicted network state (e.g., the cache state of the user and the base station), and movement patterns of users and satellites. The problem is a mixed integer nonlinear problem, which then is transformed into convex to be solved effectively. The simulation results show that the proposed prefetching scheme can improve the users’ experience.