Description

To meet the explosive demand on delivering high-definition video steams over cellular networks, we design a Social-aware video multicast (So Cast) system leveraging device-to-device (D2D) communications. One salient feature of So Cast is to stimulate effective cooperation among mobile users (clients), by making use of two types of important social ties, i.e., social trust and social reciprocity. By using So Cast, clients form groups to obtain missing packets from other clients and restore incomplete video frames, according to the unique video encoding structure. In return, the user perception of the mobile video quality can be substantially improved. Specifically, we first cast the problem of social ties based group formation among clients for cooperative video multicast as a coalitional game, and then devise a distributed algorithm to obtain the core solution (group formation) for the formulated coalitional game. Further, a resource allocation scheme is proposed for the base station to handle D2D radio resource requests from client groups. Extensive numerical studies using real video traces corroborate the significant gain using So Cast.