Contract-Based Cache Renting Mechanism in UAV-Assisted 5G Networks

To alleviate the load of the backhaul link, a mobile network operator (MNO) temporarily deploys cache-enabled unmanned aerial vehicles(UAVs) as aerial base stations to offload the traffic from a macro base station (MBS). While several content providers (CPs) desire to rent the cache space at both the MBS and UAVs to proactively place their popular videos so that their subscribers can receive low-latency services. However, the willingness for cache renting is privately for each CP, resulting in asymmetric information between the MNO and CPs. To overcome this problem, the contract theory is exploited to formulate the cache renting problem and to maximize the utility of MNO. The feasible conditions for the contract are derived, and the target optimization problem is relaxed to the convex programming problem. Finally, the KKT condition is utilized to solve the optimal contract for the cache renting. Experiments validate the effectiveness of the proposed cache renting mechanism in UAV-assisted the 5th generation of mobile communications system(5G) networks, and the influence of UAVs' flight altitude on system performance is discussed. © 2020, Editorial Department of Journal of Beijing University of Posts and Telecommunications. All right reserved.