Social-aware Content Delivery with D2D Communications Support for Emergency Scenarios in 5G Systems

In future Fifth Generation (5G) cellular systems, mobile social networks are deemed to play an important role in the information and multimedia content dissemination. From the technological perspective, Device-to-Device (D2D) communications and multicast services have been identified as potential enabling technologies for a fast and efficient content transmissions. In this paper, we propose a viral information diffusion approach that brings together these different ingredients with the objective of minimizing the content delivery time experienced by the users over the cellular infrastructure. To this aim, we model an expected diffusion time where network metrics and social relationships are combined and used to drive the choices in the dissemination process. In particular, a new metric called social network contact time is introduced, able to efficiently characterize the user behavior in checking a notification received on a smart device. A novel solution effectively combining multicast, D2D communications and social network concepts is proposed and evaluated through simulations in a wide range of scenarios. The comparison with the legacy LTE multicast technology shows how the proposed solution is able to introduce considerable gains in terms of (i) average diffusion time per user, (ii) average throughput, and (iii) Jain's fairness index.