Research On The Time Synchronization Protocol Based On Error Correction For Wireless Sensor Networks

A wireless sensor network (WSN) consists of a large number of sensor nodes, which are low-cost, low power dissipation and able to communicate through wireless signal. The development of wireless sensor networks need a lot of basic technical support, including positioning technology, security technology, data fusion technology and time synchronization technology and so on.In most of the practical applications of wireless sensor networks, the data collected by sensor nodes have practical meaning only when which include the time information. Almost all wireless sensor network applications, such as environmental monitor, data fusion, coordinated sleep, are based on the time synchronization of all sensor nodes. Therefore, time synchronization technology has the important practical significance for promoting the wide applications of wireless sensor networks.NTP (Network Time Protocol) and GPS (Global Positioning System) which are two main time synchronization protocols in Internet, which are not suitable for wireless sensor networks with low energy, low-power and complex application scenarios. Therefore, considering the characteristics of wireless sensor networks, a new time synchronization protocol that is based on error correction called TBEC (Time synchronization protocol Base on Error Correction for wireless sensor networks) is proposed in this paper. In this protocol, the base station periodically broadcasts beacon messages to the nodes, when the nodes receive the broadcast messages they wrote down the local time stamp immediately and send it to the base station for the further processing. The base station computers and saves the error value between the current node and the reference node's time for correcting the clock of the specific nodes. TBEC can reduce the energy consumption of an ordinary node effectively and extend the life cycle of the whole network consequently.In this paper, firstly, the TBEC protocol is implemented and verified on the Sun SPOT wireless sensor network experimental platform. Several single-hop experiments are conducted on Sun SPOT platform which consists of two autonomous nodes and one base station node. The experiment results show that the TBEC protocol sends less synchronization messages and can synchronize each node accurately. Secondly, in OMNET++ simulation platform to complete the TBEC, RBS, DMTS simulation, and the experimental results were analyzed and summarized. Simulation results further demonstrate the TBEC achieve a good balance in accuracy, power consumption and complexity.