Abstract:

Facing the dense wireless network communication scene assisted by unmanned aerial vehicles (UAVs),Aiming at the problem of a limited network throughput caused by transmission of fixed base stations on the ground,and focusing on the improvement of communication network performance within the coverage of UAVs,a UAV Assisted Dense network Medium Access Controlprotocol (UAD-MAC) is proposed.First,based on the heterogeneous communication of different devices in a dense network,we propose a novel UAV assisted dense wireless network communication model.Second,the concepts of initial competition window coefficient,sub-coefficient and their weights are introduced.We design a new MAC protocol by combining the design of the initial contention window and the nodes quitting probability in UAV mobile environment.Finally,a three-dimensional Markov model is used to evaluate the normalized saturated throughput and access fairness,and then we determine the sub-coefficient weights of the initial contention window to maximize the throughput.Simulation results show that the average normalized saturated throughput of the UAD-MAC protocol is nearly doubled under the basic access mechanism and increased by about 51% under the RTS/CTS mechanism compared with the existing protocol.Moreover,the loop with a smaller access time can obtain a higher throughput and lower delay.

Key words: unmanned aerial vehicle, dense wireless networks, medium access control, communication heterogeneity, saturated throughput