Content caching scheme for D2D communication underlaying cellular networks with capacoty restriction

With the rapid growth of Internet services and the popularity of social media, mobile network operators are facing a serious challenge to delivery multimedia content to multiple users. In this paper, we consider device-to-device (D2D) communication supported mobile content delivery networks (mCDNs) which enables controllable and direct delivery of multimedia contents. With this network, we regard mobile device as caching server device (CSD) which can store popular multimedia contents and provide these for other devices in proximity to it via D2D link. Besides, we propose an optimization problem to determine the caching probability for the individual content in each CSD. In this problem, we intend to maximize system utility with the consideration of cache capacity restriction in each CSD. Further, we present a low-complexity search algorithm, namely discrete binary searching algorithm (DBSA), for solving the proposed optimization problem. Simulation results show that proposed optimal solution can obtain the best performance on system utility.