Social-Aware Content Sharing In D2d Communications: An Optimal Stopping Approach

With the development of D2D (Device-to-Device) communications, the ever increasingly growing demand for content sharing caused by nearby devices can be satisfied. D2D communications based on social relationships are taken into consideration in extant literature, while how to select friends with whom users share contents efficaciously and voluntarily remains a problem. To this end, social tie, as a measurement of content similarity and mutual trust, is introduced in our work to facilitate contents sharing. In the paper, we first model friend selection problem as a finite horizon optimal stopping problem in the frame of optimal stopping theory and derive the optimal social cost threshold. We further prove the optimal social cost threshold is endowed with monotonically non-decreasing property. Moreover, we develop an iterative algorithm based on derived social cost threshold to select friends with whom users are inclined to share contents. Last but not the least, numerous simulation results validate the effectiveness of our proposed algorithm for content sharing over random D2D communications.