Optimal Content Sharing Mode Selection for Social-Aware D2D Communications

Abstract

Device-to-Device (D2D) content sharing is regarded as an effective way to support an explosion in demand for content sharing and local services. The underlying principle is that the more popular contents are cached in more user devices, and accordingly, a user would directly obtain the desired contents from one/some of its neighbours via D2D communications. Due to the random content location, and the limited storage and transmission capacity of devices, how to optimally match potential providers to demanders of contents is of importance. In this letter, we define the social-aware user connection performance by integrating the average link rate and the social reciprocity, where the former ensures the successful content delivery, and the latter stimulates mutual cooperation. Subsequently, we construct a general social welfare maximization to formulate the social-aware content sharing mode selection problem. Due to its intractability, we exploit the properties of total unimodularity to simplify it to its linear relaxation without loss of optimization. In this way, the proposed scheme not only integrates the advantages of physical and social information, but also provides a universal paradigm to achieve the optimal matching between demanders and potential providers through simple and online implementation.