基于TDMA技术的无线传感器网络时间同步新方法

New method of time synchronization for wireless sensor network using TDMA technology

时间同步技术对于无线传感器网络的正常工作以及运转效率来讲都至关重要,是不可或缺的一环。传统的时间同步算法主要针对于节点信息包传输过程中的时间延迟和节点时钟的偏移和漂移,但由于很多复杂因素的影响,这一类时间同步算法的同步精度都不是很高。对此,将时分多址(TDMA)技术用于无线传感器网络的时间同步,网关节点发送信标通知各节点时隙分配,并且利用了节点侦听使得那些不在网关通信半径内的节点也能获取到时隙的情况,各节点在自己分配得到的时隙内发送消息。最后将媒体访问控制(MAC)子层的TDMA协议与网络层汇聚树协议(CTP)结合,通过对丢包率的计算来分析所提出方法的效果。实验结果表明,应用了TDMA技术后,丢包率明显减小,说明了TDMA对时间同步有很好的效果。

Time synchronization technology is critical to the normal work and operational efficiency of wireless sensor networks. It’s an indispensable part. The traditional time synchronization algorithm is mainly used for time delay during node packet transmission and offset and drift of the node clock. But due to the influence of many complicated factors, the synchronization accuracy is not very high. So this paper uses time division multiple access(TDMA) technology for time synchronization of wireless sensor networks. The gateway node sends a beacon to notify each node of the time slot allocation. Simultaneously, those nodes that are not within the communication radius of the gateway use node listening to obtain the time slot situation. Each node sends a message in its assigned slot. Finally, the TDMA protocol of the media access control(MAC) sub-layer is combined with tree cluster tree protocol(CTP) to analyze the effect of the proposed method by calculating the packet loss rate. The experimental results show that the packet loss rate decreases significantly after TDMA is applied, indicating that TDMA has a good effect on time synchronization.