Contract-based Dynamic Incentive Mechanism For Multi-UAV Networks

With the development of wireless communication,smart mobile terminals have been rapidly popularized,and mobile data traffic has also shown rapid growth.It is difficult for existing wireless communication technologies to meet this demand.Due to their flexible deployment and low cost,Unmanned Aerial Vehicles(UAVs)have been widely used in wireless networks.However,considering their selfishness property,UAVs may be reluctant to take part in wireless data reception and transmission without any incentive.Moreover,due to the dynamic position of UAVs and dynamic condition of the transmission channel,resulting in dynamic asymmetry in network information.Therefore,this paper concentrates on contract theory-based mechanism to solve the asymmetric information problem in the UAV networks.Cooperative communication is a promising technique to mitigate channel impairment and improve spectrum efficiency.Due to the selfish nature of UAVs,how to provide proper long-term incentives for UAVs in dynamic communication environments is an essential issue.In this paper,a two-period dynamic contract is proposed under the dynamic asymmetric information scenario.Considering the UAVs’ types are independent in both periods with identical probability distribution,the contract-theoretic model for ability discrimination relay selection is formulated.And the necessary and sufficient conditions for the optimal contract are systematically characterized.To maximize the source’s expected utility,a sequential optimization algorithm is proposed to obtain the optimal relay-reward strategy.Simulation results show that the optimal dynamic contract design scheme is effective in improving system performance for cooperative communication.Traffic offloading is considered to be a promising technology in the UAVs-assisted cellular networks.Due to their selfishness property,UAVs may be reluctant to take part in traffic offloading without any incentive.Moreover,considering the dynamic position of UAVs and dynamic condition of the transmission channel,it is challenging to design a long-term effective incentive mechanism for multi-UAV networks.In this work,the dynamic contract incentive approach is studied to attract UAVs to participate in traffic offloading effectively.The two-stage contract incentive method is introduced under the information symmetric scenario and the information asymmetric scenario.Considering the sufficient conditions and necessary conditions in the contract design,a sequence optimization algorithm is investigated to acquire the maximum expected utility of base station.Simulation experiment shows that the designed two-stage dynamic contract improves the performance of traffic offloading effectively.