A New Time Synchronization Method For Wireless Sensor Network Based On SFD

As a fusion of wireless communication technology, sensor technology and embeddedtechnology, WSN(wireless sensor network) is an emerging network technology whichconnects the physical objects information of objective world with the transmission network. Itis a broad promising way to acquire information, and is a research hotspot at home and abroad.Time synchronization as an important technology, provides a unified time for distributedwireless sensor network, and is the foundation and guarantee for wireless sensor network dataacquisition and processing.This paper introduces the development and system structure of the wireless sensornetwork, and then reviews the definition, time model and factors affecting the precision oftime synchronization, introduces the classification of time synchronization algorithm: Basedon the sender-receiver time synchronization algorithm, and based on the receiver-receivertime synchronization algorithm. The sender-receiver time synchronization algorithm includesthe one-way and the two-way sender–receiver time synchronization algorithm. Thendescribed in detail with the representative time synchronization algorithm of the abovecategories: DMTS, TPSN and RBS.After that proposed a based on SFD wireless sensor network time synchronizationmethod, achieve point to point time synchronization for sensor nodes. Then, use thepoint-to-point method above in the chain sensor network topology, analyze the disadvantageof this point-to-point method above. Then, on the basis of the point-to-point method above,proposes a based on SFD time synchronization method for WSN which merges thesender-receiver and the receiver-receiver time synchronization method, achieve timesynchronization for the whole sensor network. The synchronization process of traditionalsender-receiver time synchronization algorithm is simple, but the error is bigger. The error oftraditional receiver-receiver synchronization algorithm is smaller, but the process is complex,especially in large scale network, which will lead to very high synchronization energyconsumption. It is also not applicable to a chain network topology. The method proposedabove solves these two problems, synchronized with flooding, dynamically built the virtualnetwork level in one synchronization process, so to make the whole sensor networksynchronized. Compared to the traditional sender-receiver time synchronization method, themethod in this paper can improve the synchronization precision; compared to the traditionalreceiver-receiver time synchronization method, the method in this paper can reduce thecomplexity of synchronization process, and reduce synchronization energy consumption. The point to point time synchronization method based on SFD uses the CC2530development kit consists of CC2530EM and SmartRF05EB-M development board toexperiment, realized microsecond-level time synchronization and calculated the SFD signaldelayed between the sender and the receiver based on the synchronization error between twopoints; The method based on SFD which merges sender-receiver and receiver-receiver timesynchronization method uses OMNeT++simulation platform, simulating wireless sensornetwork, to achieve the time synchronization of the whole network. Then verify and analyzethe correctness and feasibility of the method from three aspects of synchronization error,synchronization cycle and synchronization energy.