Research On Routing Algorithm Of Large-scale UAV Ad Hoc Network Based On Virtual Backbone Network

At present,UAVs are widely used in various military and civilian scenarios,such as collaborative reconnaissance,precision agriculture,search and rescue,etc.With the rapid development of science and technology and the improvement of application scenario requirements,UAV ad hoc networking is developing in a large-scale direction.Compared with small and medium-scale ad hoc networks,large-scale ad hoc networks have the advantages of wide coverage,high task completion efficiency.However,the increase of network scale brings great challenge to the design of routing protocol.The network performance of large-scale UAV network is unstable due to the fast node movement speed and unstable link.Due to limited energy,if a UAV suddenly loses power and exits the network,the network life and performance will be affected.Due to unstable link status,frequent network maintenance by nodes will lead to excessive routing cost,and even cause network congestion,which seriously affects network scalability and other problems.,this thesis proposes a routing protocol suitable for this scenario.The main research work of the thesis is as follows:Aiming at the problems of unstable network performance caused by fast node speed and unstable link of UAV network and limited energy of UAVs,an improved protocol named IEBATMAN is proposed based on Better Approach To Mobile Ad-hoc Networking.Because the routing mechanism of nodes in BATMAN based on Transmit Quality value cannot reflect the current link state in real time,it will affect the response speed of nodes to link changes,path switching speed,and network communication delay and other performance.In addition,the researchers did not consider the problem of energy consumption when designing the protocol,so this thesis improved the protocol from the calculation mechanism of Transmit Quality value and the format design of protocol packet,so that the improved protocol is more suitable for UAV network.Simulation results show that IEBATMAN has improved performance in terms of delay,packet transfer and energy consumption.However,the performance of this protocol in terms of routing overhead needs to be further improved.In order to solve the problems of network congestion and low scalability caused by increasing nodes and routing overhead in large-scale ad hoc network of UAVs,this thesis designs a virtual backbone network construction algorithm WUCDS based on Connected Dominating Set.In order to improve the stability and lifetime of the network,comprehensive factors such as the number of adjacent nodes,node residual energy and local available bandwidth are considered in calculating the node weight.The improvement of the running rules of UCDS algorithm can effectively improve the robustness of the algorithm and reduce the time of constructing virtual backbone network.The mechanism of redundancy elimination and backbone network maintenance can further control network routing cost and maintain network stability.Based on the above research,a hybrid routing mechanism VBBATMAN suitable for large-scale UAV ad hoc networking is designed.According to the existing hierarchical routing mechanism,the improved active route is run on backbone link,and the on-demand route is run on non-backbone link.Finally,the simulation analysis of hybrid routing mechanism is carried out on NS3.The simulation results show that VBBATMAN has improved the performance of delay,jitter,routing cost and energy consumption in different degrees.