Research On Topology Control Technologies For Biconnectivity Of Flying Ad Hoc Networks

Swarming Unmanned Aerial Vehicles(UAVs)systems based on Flying Ad Hoc Networks(FANETs)have attracted great attention in the UAVs' application and research field.Compared with the existing ground Ad Hoc networks,there are more challenges for FANETs in terms of network dynamics,robustness and available resources.Specifically,the relative motion between nodes is significant,and network topology easily presents intermittent connectivity;Network nodes and links are easily to fail,network robustness is poor;Small UAV has limited computation,communication and energy resources,it's hard to get a balance between network performance and network cost.It's a crucial problem to maintain persistent connectivity and fault-tolerance of FANETs with effective and low cost topology control algorithms,which is the basis of real-time and reliabiligy information exchange between flying nodes.Begin with the basic requirements of connectivity and fault-tolerance of network topology,this paper systematically studies the detection and maintenance of 2-connectivity of FANETs topology for swarmming UAVs.And a series of 2-connectivity detection couple with optimization algorithms with low co st are proposed.The specific research process is as follows,in order to simulate the movement characteristics of swarming UAVs,we construct the Boid-based swarming UAV movement(BSUM)model.Furthermore,we study the topology features of FANETs based on BSUM and draw the conclusion that there are strong correlation between local critical nodes and global critical nodes in FANETs.The network topology 2-connectivity problem is analyzed based on graph theory,which is transferred into the critical ndoes detection problem,and a distributed critical nodes detection algorithm based on partial routing information is proposed(CDBPR).CDBPR make full use of the existing network parameters to extract the topological information and thus greatly reducing the overhead of the topology probe process.Given all the critical nodes in the networks,in order to elininate the influence of critical nodes and restore the 2-connectivity of network topology,this paper proposes a topology power control algorithm based on the simplified block-cut tree(SBBPC).By modeling the network topologies with critical nodes into simplified block-cut trees,it greatly simplifies the searching process of the feasible augmentation edges set,simulation results verifiy the superiority of the proposed algorithm in overhead reducing.Constrained by the maximum transmission power of flight platform,SBBPC algorithm does not always output a available so lution of augmentaton edges set.This paper proposes a distributed nodes movement control algorithm based on virtual potential field(DMCBP)to be a substitute algorithm of SBBPC to restore the 2-connectivity of FANETs topology.The implement of virtual potential effectively solves the oscillation problem of the algorithm in the case of multiple critical nodes existing.Nodes determine the convergence direction as the steepest descent of the virtual potential field,which can achieves immediately response to the dispatch process.Compared with several typical node mobility control algorithms,the simulation results show that the DMCBP algorithm has near or even better performance compared with the existing algorithms,while significantly reduces the algorithm overhead and delay of the algorithm.