LAUSR

Device-to-device (D2D) relaying in a store-carry-forward manner can efficiently expand the transmission range of D2D traffic offloading in cellular systems, which needs external incentives to promote the cooperation of relay nodes who are tend to be selfish. Different to the existing incentive mechanisms which usually adopt large enough incentives, we propose a moderate incentive-compatible data forwarding mechanism based on the Markov decision process (MDP) framework with the principal-agent model. The main idea of this mechanism is to dynamically adjust the payment to incentivize the relay nodes to forward the data with an appropriate radius such that the system utility is maximized. Due to the curse of dimensionality in solving MDP, we propose a greedy algorithm which considers the past information only and further prove its optimality. For discussing the implementation of the proposed solution, we propose an infrastructure-assisted D2D relaying protocol for cellular systems. Simulation results show that our proposed moderate incentive mechanism can achieve a better performance on system utility compared to existing incentive mechanisms.