Social-aware file-sharing mechanism for device-to-device communications

Device-to-device (D2D) communication technology can significantly improve energy efficiency and offload base station traffic. It has become a new research focus in next generation mobile communications. In this paper, a file-sharing mechanism based on social networks is proposed for the D2D communication system underlaying cellular networks aiming at improving the users' quality of experience (QoE). In the proposed mechanism, all users are divided into several groups according to the documentation requirements. Then the D2D communication links are built within each group by fully considering the social relationships and trust degrees of users. The target files give priority to be shared through the D2D mode. Theoretical analysis and extensive simulation results show clearly that the social relationships can affect the whole wireless networks significantly. Selecting a user with the largest social degree as a central user can greatly reduce the transmission delay, relieve the heavy burden of base stations and then optimize the overall performance of cellular communication systems.