The Research On Distributed Topology Repair Algorithm For Node Failure In Wireless Sensor Networks

Node failure in wireless sensor network will change the original network topology,thus affecting network performance,so it is necessary to repair the network topology after nodes failure.Network topology repair is to adjust the network topology after nodes failure to restore the network connectivity and coverage to the level before the failure.The existing topology repair algorithms have some problems such as large moving distance and long repair time,and the research on topology repair of multiple nodes simultaneous failure is insufficient.In order to reduce the cost,most topology repair algorithms need to determine in advance whether the faulty node is an indispensable key node for network connectivity,but the existing key node detection algorithm has some problems such as low detection accuracy and high information overhead.The main work of this paper includes the following two aspects:Aiming at the problems of existing critical node detection algorithms,this paper proposes a distributed critical node detection algorithm based on neighbor partition table(CNDNPT).CNDNPT algorithm is an expandable algorithm for critical node detection based on neighbor information.Based on the neighbor information,the algorithm constructs a data table that reflects the partitions of the local network – Neighbor Partition Table(NPT),and determines whether a node is a critical node according to the structure of the table,and further improves the accuracy of judgment by expanding the table.Simulation results show that CNDNPT can accurately detect the key nodes in the network,and the information cost is relatively low.Aiming at the problems of existing network topology repair algorithms,a set of distributed topology repair algorithms based on neighbor partition table(TRNPT)is proposed in this paper.Among them,TRNPT-ON is a repair algorithm for single ordinary node failure.It selects the most suitable node to move to the faulty node to compensate network coverage.Trnpt-cn is a repair algorithm for the failure of single critical node.By selecting a agent nodes group,the network topology is repaired by dynamically programmed nodes movement.Trnpt-smn is a repair algorithm for the simultaneous failure of specific multiple nodes.It determines the generation of network split by neighbor partition table and uses dynamic node movement to repair.The simulation results show that the TRNPT-ON algorithm can well compensate network coverage after a single ordinary node failure,and the distance of node movement is relatively small.The TRNPT-CN algorithm can quickly repair network topology with short travel distance,and reduce the possibility of secondary node failure.Trnpt-smn can quickly detect network fragmentation caused by simultaneous failure of several nodes and repair the network through distributed node movement.