Overlapping Coalitions for D2D-supported Data Uploading in LTE-A Systems

This paper investigates on novel effective schemes based on Device-to-Device (D2D) communications for data relaying, to upload content from a set of cooperating User Equipments (UEs) acting as sources of the data towards a cellular base station (eNodeB). Enabling factors of the resulting cooperative data uploading able to improve the system performance are: (i) the differentiated channel quality experienced by UEs and (ii) the introduced possibility to pool together the allocated radio resources. A constrained coalition formation game is used for multi-hop D2D overlapping coalition formation, where the time needed to upload the content is the utility for the players. The proposed model directly considers the coverage constraints for the D2D links among the players. The proposed solution allows to determine the final cooperating network topology as a tree of overlapping coalitions. We demonstrate that the solution guarantees an average gain in the uploading time for the UEs up to a 23% with respect to non-cooperative content uploading methods.