Research On Energy Saving Technology Of ZigBee Network Based On Clock Synchronization

The progress of sensor technology and wireless communication technology promote the rapidly development of wireless sensor network.The ZigBee technology,with its advantages of low power consumption,self-organization and convenient networking attracted more and more attention and research,Widely used in military, household and medical and other fields.However in fields ZigBee used,the huge number of nodes, the deployment of complex environment and energy supply is limited which makes the characteristics of energy becoming a key resource in wireless sensor networks.so how to effectively save energy, prolong the period of working nodes of the network have become the focus of research.This thesis first introduces the ZigBee technology and its application fileds,Briefly describes the structure of ZigBee protocol stack and the function of each part, and at the same time introduce the requirements of time synchronization technology and some popular time synchronization algorithm.Then build a ZigBee wireless network system,on the premise of analyse network requirements put forward the system design scheme,then complete the hardware design of gateway and ZigBee node.Next complete the gateway program design which achieve communication between users and ZigBee nodes.Complete the program of ZigBee network building,and the network consists of several nodes and coordinator.Design android software that running on a handheld device.This software can inquiry and set the network parameters,at the same time communication with sensor.Finally testing the Performance of system,the test is performance test of ZigBee communication system,the test results meet the design requirements.On the basis of system is completed.through comparing the characteristics of different energy saving method,put forward two energy saving mechanism based on sleep/wake methods:Asynchronous clock dormancy mechanismand the dormancy mechanism of synchronous clock.First analyzes the principles as well as the advantages and disadvantages,then compare their power at the same time.Obtain the conclusion that clock synchronization mechanism has more advantage in this system. Because the traditional wireless time synchronization algorithm was high energy consumption and time synchronization error.proposes a synchronization algorithm based on kalman filter time.First establishes the system clock model.then the local clock correcting its clock by exchanging time message with standard clock.For the synchronous accuracy is poorer.should use the kalman filtering and linear quadratic optimal control tracking algorithm to correct the state variables,therefor improve the clock Synchronization accuracy.Finally the simulation verify the feasibility of the algorithm.