Research On Communication Technology Of UAV Formation Based On 5G

Thanks to artificial intelligence,computer vision and other technologies,UAV formations can cooperate to complete various aerial tasks through information interaction and active collision avoidance between the UAVs.The next-generation 5G mobile cellular network can not only provide reliable signal coverage for UAV formations,but also ensure efficient D2 D communication among UAV formation.However,the reliability and security of UAV formation communications are affected by malicious users,transmission of false information by malicious users can cause serious damage to UAV formations.At the same time,due to the fast speed and flexible trajectory of UAV,the 5G mobility management mechanism is also critical to the communication performance of the UAV formation.In this paper,the reliability of direct communication between UAV formations and the mobility management of 5G service UAV formation will be deeply studied.The specific research findings and contributions are summarized as follows:During flight,UAV formations can perform mission allocation,active collision avoidance,and trajectory planning through information interaction,improving the efficiency of formation collaboration.However,when UAVs share information with others,malicious(or malfunctioning)users may broadcast false(or wrong)information,causing other UAVs to make wrong decisions and incur serious consequences.UAVs should be able to identify these malicious users when communicating with others directly,so it is especially important to know the real-time reputation value of the surrounding UAVs.In response to the need to know real-time reputation value of other UAVs during direct communication among UAV formations,a UAV reputation management mechanism based on a hierarchical blockchain is proposed.According to different levels of airspace where UAVs are located,the hierarchical blockchain is used to manage and record their reputation value to reduce the computing power consumption and block propagation delay of UAVs.Secondly,the blockchain structure of the UAV reputation management mechanism is designed to increase the capacity of the blockchain and reduce the confirmation delay of reputation information through a combination of microblocks and keyblocks.The blockchain structure is also optimized for selfish-mining attacks,improving its security.Simulation results show that the proposed mechanism can not only reduce the delay of block propagation,but also improve the real-time performance of the UAV reputation value update.The communication performance between the UAV formation and the base station determines whether the UAV formation can accurately receive flight control instructions.The mobility management of the UAV formation has an important impact on the communication performance of the downlink.Aiming at the frequent handover caused by the downlink quality fluctuations of UAVs,a dynamic handover parameter change mechanism is proposed.The trigger parameters of the handover events are dynamically modified according to the real-time measurement results reported by the UAVs to reduce the frequency of the UAV handover.Secondly,a handover mechanism based on UAV trajectory information assistance is also proposed to avoid unnecessary handover due to lobe zero and trajectory factors in multiple flight modes.A 5G-based UAV formation mobility management system-level simulation platform was built using NS3 and we implement the proposed mechanism on it.The system-level simulation validates the improvement of the proposed mechanism on the mobility management performance of the UAV formation.