Research On Topology Control Algorithms For Wireless Sensor Networks

Wireless Sensor Networks(WSN) which are composed of a large number of small, low-cost and low-power sensor nodes, and constructed by self-organized in wireless multi-hop mode. The targets of WSN are cooperative sensing, collecting and processing the information of sense objects in the area which the WSN covered, and then send the data to the observer. WSN have been used in a variety of applications such as environmental monitoring, weather report, navigation, communication, medical treatment, military applications and so on.The power of the sensor nodes in WSN is usually supplied by energy-limited battery. Therefore, the most important issue in WSN is saving energy and prolonging network lifetime through power-efficient strategy. In the application on environment monitoring, the nodes work on complicated and dangerous regions, so their batteries can not be supplemented or replaced. So, reducing power consumption and prolonging the network lifetime are very important. Topology control is one of the most important problems in WSN. Usually there are millions of nodes in a WSN, the nodes are distributed widely and deployed in irregularly, so it's hard to be controlled centralized. The nodes must be controlled distributed.In this paper, the structure and the characteristic of sensor network are introduced firstly. Meanwhile, several typical topology control algorithms are analyzed deeply. Then, a cluster-based distributed wireless sensor networks topology control algorithm (CDTC) is presented. The cluster method is used to divide the WSN to several clusters which can be overlapping by others. And in these clusters, cluster-heads run the local minimum spanning tree algorithm (MST) and order other nodes in cluster to build up the neighbor relationship, adjust transmission power, and then a suitable topology is constructed. Simulation show that after run CDTC, the average link length is lower, and the node's degree is less than 6, and average node's transmission power is lower, these mean the contention is reduced, the global power consumption is decreased, and the network's lifetime is prolonged.