Research On Mobile Data Collection Optimization Algorithm In Wireless Sensor Networks

Wireless Sensor Networks(WSNs)are widely used in military,health monitoring and environment protection due to their low power consumption,self-organization.Traditionally,there are two ways to transmit the collected data to the sink for sensor nodes: single-hop transmission with long distance communication or multi-hop transmission with short distance communication.However,the transmission with long distance communication is not in accordance with the realistic conditions of the wireless sensor nodes which have limited energy,and multi-hop transmission increases the energy consumption of nodes between the source node and the sink.In order to reduce the energy consumption of sensor nodes,the mobile sink is introduced to move among the sensor nodes and collects data from each sensor node with short-distance communication and single-hop transmission.In view of the delay caused by the mobile sink,this thesis proposes to cluster the wireless sensor network to form a hierarchical network topology which consists of cluster heads and cluster members,and the mobile sink collect data from cluster heads.This thesis consists of two parts: clustering algorithm for the wireless sensor network and path planning based on the mobile sink.(1)We propose the clustering algorithm based on the energy and density in this thesis.In our clustering algorithm,the selection of cluster head not only considers the residual energy of nodes but also considers the density of neighbor nodes.In the result of the algorithm,the selected cluster head is located in the middle of the cluster,the number of nodes in each cluster is balanced and the distance between cluster member and cluster head is less than the single-hop transmission distance.It achieves the goal of balancing the network load and prolonging the network cycle.(2)We propose the path planning based on the mobile sink includes inter-cluster path and intracluster path.The clustering algorithm divides the wireless sensor network into several large clusters,and cluster heads in a large cluster form a cluster head sequence based on distance.In inter-cluster path,the mobile sink visits the cluster heads in a large cluster according to the cluster head sequence.In intra-cluster path,the mobile sink selects the nearest large cluster as the next visiting large cluster based on the nearest neighbor selection principle.The experimental results show that the moving path of the mobile sink is shortened and the data collection delay is reduced.