Mobility-embedded and social-aware distributed caching for D2D content sharing

It has attracted much attention recently that cache-enabled users exploit device-to-device (D2D) communications to allow content sharing between them, resulting in higher spectral efficiency and lower energy consumption. However, due to the various interests of users, it is helpful for a user to cache the desired contents of its neighboring users by predicting their interests. Moreover, due to the mobility of users, content sharing becomes an opportunistic behavior. In this paper, considering the mobility and different interests of users, we propose a mobility-embedded and social-aware distributed caching scheme, where contents are divided into partitions and cached in the form of partition. We prove that the problem is a monotone submodular function over one matroid and multiple knapsack constraints and propose a greedy algorithm to solve it. Simulation results show that our scheme gains significant cache benefits.