The Research Of Data Collection Based On Virtual Cluster-head Strategy In Mobile Wireless Sensor Network

Wireless sensor network (WSN) is a data-centric network. How to achieve sensor data collection efficiently is a key technology of WSN application. With mobile WSN development, data transaction needs maintaining a large number of network control information if still use traditional data collecting mode. The requirement to node process capability will be increased. It also seriously impacts on the network performance, can not satisfy the mobility requirements. Researching on data collection strategy for multi-tier mobile WSN is a very important subject.We propose a data collection strategy base on virtual cluster-head (VCDC) for multi-tier mobile WSN. The policy uses cluster-tree data collection mixed mode. It has both advantage of cluster and tree mode, and improves the overall performance of the network. The paper has two main aspects of research work: virtual cluster-head election base on weight value and plan mobile path of F node. The main job is as follows:Virtual cluster-head election base on weight value: After achieve its location information, each sensor node balances the value of its neighbor nodes, surplus energy and distance to each other to elect the virtual cluster-head in the cluster. The cluster-head only need to notify its location information to F node, no require collecting and relay sensor data. This will be done by F node. In order to reduce network energy consumption and maintain the stability of cluster, new virtual cluster-head will be elected when old one surplus energy less than fixed value. It can decrease rebuild network times, enhance network stability and prolong the network lifetime.Plan mobile path of F node: Make each virtual cluster-head for vertex, distance between two nodes for weight value, select one vertex for root randomly to build a minimum spanning tree (MST). MST is a path will pass each virtual cluster-head in monitor area. F node according this path to traverse all cluster once each cycle, and stay sometime when pass a vertex to collect sensor data. It makes sure that F node can stability and reliability receive all sensor information from S nodes in the cluster.Simulation results show that cluster-tree data collection mixed mode can reduce affection of S node movement, ensure F node timely, reliable and low energy consumption to collect information, and prolong network lifetime while S nodes have the same performance. It satisfies the requirement for mobile WSN application. F node mobile control strategy solves the problem of network instability and high data losses induced by node movement. It will achieve higher network coverage and lower data losses while deploy a little F nodes.