The Research On Time Synchronization Mechanism For Clustering Wireless Sensor Network

Wireless sensor network (WSN) is a new type of network which sensor nodes widely are deployed in the monitored the environment. It can automatically sense, gather information which is processed in accordance with the design requirements and then is passed to the monitor of the network. In recent years, with the rapid development of the micro sensor technology, computer technology and wireless network technology, wireless sensor network has become a new hot spot which has attracted great concern of the researchers at home and abroad.Time synchronization technology is an important part of the basis of wireless sensor network. Time synchronization mechanism’s quality is directly related to the performance of related technologies in the wireless sensor network. At the same time, for object oriented application of wireless sensor network, the information lacking of precise time is useless. NTP time synchronization protocol and GPS time synchronization technology which have been widely used in the field of traditional Internet cannot be directly used in the wireless sensor network due to the wireless sensor network’s constraints. Therefore, time synchronization mechanism is becoming a hot spot which has been focused on by the researchers of the wireless sensor network.This paper analyzed several kinds of existing classic time synchronization algorithms. More time synchronization algorithms are used in single-hop networks and their precision has reached microsecond. But with the development of the wireless sensor network technology, large-scale network will become the development trend of it. However, the existing time synchronization algorithms are to improve their precision by sacrificing part of the energy consumption of sensor nodes in network multiple-hop network. Therefore, how to increase the time synchronization accuracy on the basis of reducing the energy consumption in multiple-hop network time becomes a research topic of this paper.This paper puts forward a new time synchronization algorithm based on clustering network structure in the multi-hop wireless sensor network. Main research works were carried out as follows:1. Put forward a kind of optimized topology control algorithm based on LEACH algorithm. In this algorithm, the cluster-head node’s selection of threshold value was redesigned, and the concept of assistant cluster head node and selecting threshold were put forward. At the same time the working time threshold of the cluster-head nodes was set according to the residual energy of them. By optimizing the topology control algorithm, the new algorithm balanced the energy consumption of the cluster head node, improved the network energy utilization, reduced the hop of wireless sensor networks, avoided the growth of time synchronization error with the increase of the account of the hop.2. In the algorithm of time synchronization phase, two-way time synchronization mechanism and one-way broadcast time synchronization mechanism were used to reduce the time delay of time synchronization message and improve the time synchronization precision.3. Finally, in this paper, the optimization of topology control algorithm and time synchronization algorithm were simulated. The experimental results showed that they could improve the precision of time synchronization, reduce the network information exchange capacity and the node energy consumption and increase the life span of the network.