Joint caching policies for optimizing energy costs/offloading probability for D2D and millimeter‐wave small cell underlaying cache‐enabled networks

AbstractAbstractCache‐enabled networks are a promising solution to high video traffic, which allows popular files to cache at the user equipment (UE) and base stations (BSs). To improve the efficiency of file transmission, we adopt full‐duplex (FD) radio technology and millimeter‐wave small BSs (mmSBSs) in our network scenario. In this paper, users can get their required files via one of self‐communication, FD device‐to‐device (D2D) communication, mmSBS communication and macro BS (MBS) communication. Different communication modes have different energy costs. To minimize energy costs/maximize offloading probability, we analyze the successful probability for users to obtain files by different communication modes and propose an optimal joint caching policy for UE and mmSBSs. Based on the impact between UE and mmSBSs' caching policy, a suboptimal joint caching policy is proposed. The numerical results shown our optimal joint caching policy can improve the performance of cache‐enabled networks effectively and the suboptimal joint caching policy is more closer to the optimal caching policy than other common caching policies. View Figure Appropriate content caching strategy can effectively improve the performance of cache‐enabled networks. We use the stochastic geometry method to analyze the probability of users choosing different communication modes respectively, and take the energy costs/offloading probability as the optimization goal, we propose the optimal joint cache strategy of the small base station and the user terminal. At the same time, based on the interaction between small base station and terminal cache, a simple suboptimal cache strategy is proposed.