Collaborative Hierarchical Caching Strategy in D2D-Enabled Heterogeneous Networks

Abstract

To deal with the surge of wireless data traffic for massive mobile users, edge caching technology has emerged as a potential solution for next-generation wireless networks. In this paper, we study the cache placement problem in the complex heterogeneous networks, by taking into account user mobility and diverse content preferences of different users. We propose a hierarchical cooperative caching framework, in which not only nearby users can share local contents by device-to-device communications but also small base stations within the same network domain can communicate with each other. Under the framework, a collaborative hierarchical caching strategy is proposed to minimize the system cost, in terms of download delay, energy or bandwidth usage. Simulation results show that the proposed collaborative hierarchical caching strategy can greatly reduce the system cost compared to the exiting proactive caching strategy.