基于移动参考节点的无线传感器时钟同步方法

现有对无线传感器网络节点中的时钟同步方法往往通过固定参考节点传递同步信息完成同步。对于固定参考节点通信范围外的节点，需要同步信息在节点间的多跳传输，这造成时间误差的累积以及节点多跳传输的能量损耗，从而影响同步的精度和网络能耗。为解决此问题，提出了基于移动参考节点和最优移动路径的时钟同步方法。首先，采用正六边形的蜂窝覆盖技术选取最优的时钟同步点。其次，结合最优覆盖和选址问题的数学模型，设计最短移动距离的路径。最后，提出了基于MAC层标记多个时间戳实现低能耗单跳同步的机制。与现有方法的实验对比表明，该方法提高了同步时间精度，并降低了通信能耗。

Time synchronization method for wireless sensor networks based on mobile reference nodes

Most existing time synchronization methods in wireless sensor networks depend on the existence of one or more fixed reference nodes and on the propagation of synchronization messages in the networks. Thus, they often suffer from the disadvantages of high energy consumption and large cumulative error due to multiple layers of communication. To address such issues, a new time synchronization method based on a mobile reference node and the optimal mobile path is proposed. Firstly, the cellular coverage technique is analyzed to identify the optimal synchronization points. Then, the optimal mobile path with minimal length is designed. Finally, an efficient single hop time synchronize mechanism based on multiple timestamps in the MAC layer is presented. Comparison with other methods shows that the proposed method can achieve both higher synchronization accuracy and lower energy consumption.