Joint Content Sharing and Incentive Mechanism for Cache-Enabled Device-to-Device Networks

Cache-enabled device-to-device (C-D2D) networks allow the constituent user devices to share their cached content with other user devices through D2D communication. As a result, the communication delay of participating users is minimized in C-D2D networks. Clearly, the success of C-D2D networks relies on the willingness of the participating users to share their cached content. In this paper, we analyze the interaction among participating cache-enabled D2D users and determine their caching, sharing, and reward decisions to minimize the users’ total cost. In view of the fact that the participating users have heterogeneous content interest profile (CIP) and storage capacity, and are self-centric, there is a need to design a fair incentive mechanism to encourage cooperation among users. To this end, we model the interaction among the D2D users as a multi-person bargaining game and design a novel incentive mechanism using the Nash bargaining solution (NBS) approach. The proposed incentive mechanism is capable of minimizing users’ total costs while ensuring fair reward transfer among participating users. Further, we proposed a distributed algorithm which allows the execution of the proposed mechanism without any involvement of base station (BS), which is much needed for autonomous D2D networks. The simulation results demonstrate that the proposed mechanism improves fairness by at least 74% and reduces the users’ total cost by at least 13.83% compared to the benchmark schemes.