Cache Allocation Scheme in Information-Centric Satellite-Terrestrial Integrated Networks

With the development of satellite communication technologies, satellite-terrestrial integrated network (STIN) is often used for content delivery services as satellites are with wide-area coverage. In terrestrial networks, in-network caching has been proved to be an effective method to improve network performance in terms of throughput and delay, so information-centric networking (ICN) will be deployed in STIN architecture (STI(^{2})CN). However, the current cache research scenarios in satellite networks usually ignore cache cooperation among nodes, resulting in lower cache hit rate. Secondly, the cache configuration is mainly implemented in the coverage area, which does not consider satellites mobility and dynamic network topology, so that network transmission efficiency is decreased. Thus, we formulate cache content allocation problem as user average hop count minimization problem, which is solved by matching algorithm to obtain exchange stability between satellites and contents. In addition, a proactive pushing scheme is proposed to solve satellites mobility problem. The cached contents will be pushed to the subsequent satellite covering the area in advance to further improve content retrieval efficiency. Simulation results show that the proposed scheme can significantly reduce user average hop count and improve cache hit rate.