Operator's Economy of Device-to-Device Offloading in Underlaying Cellular Networks

Offloading onto Device-to-Device (D2D) communications has been considered as a promising technology to alleviate the traffic load of cellular networks. However, the success of D2D communications actually relies on the willingness for users to share contents and operator’s incentives to tolerate interference in networks, which has been overlooked in most literature. We therefore propose an incentive framework of D2D offloading, where the operator encourages some users acting as D2D transmitters to broadcast their popular contents to nearby region in order to improve operators overall economic efficiency. A two-stage Stackelberg game is employed to analytically model such interaction: The operator (leader) determines the incentive price to maximize its interests, and accordingly D2D transmitters (followers) choose appropriate traffic volume to be offloaded. Furthermore, the transmit powers at base station (BS) and D2D transmitters are simultaneously characterized by considering the intra-tier and inter-tier interferences in complex cellular networks. Simulations confirms that cellular operator can fully utilize the spectrum and thus significantly increase its profit by incorporating this D2D offloading incentive mechanism.