改进的无线传感器网络平均时间同步算法

摘要

In most of previous time synchronization algorithms for wireless sensor networks (WSN),common nodes often synchronize their clocks to a reference (or root) node,which is easily disturbed by incidental events (like invalidation of circuit or power down of root node). In this paper,IATS (Improved Average Time Synchronization) algorithm,which synchronizes all the nodes’ clock to their average,is presented based on the improvement of the ATSP (Average Time Synchronization Protocol). First of all,ROS (Receiver-On-ly Synchronization) approach is adopted in IATS,which aims at minimizing the number of message transmissions without loss in syn-chronization accuracy. What’s more,a diffusion-based method using ROS,which finds the optimum set of pairwise synchronization for energy conservation,spreads the local time synchronization to the entire network to achieve global synchronization. The novel ideas and methods in the dissertation have been studied and verified through theoretic analysis and simulations,which have showed the feasibility.%　　在过去的大多数无线传感器网络时间同步算法中，普通节点通常将时钟与参考节点(或根节点)同步，这很容易被意外事件所干扰(如环路失效或根节点掉电)。文中基于对ATSP(平均时间同步协议)的改进，提出了一种将所有节点时钟同步到它们的平均值的算法-IATS(改进的平均时间同步)算法。首先，在IATS算法中采用ROS(仅接收同步)的方法最小化报文发送量而不失同步精度。此外，基于ROS的扩散机制通过寻找最优同步序列对来节省能耗，并把本地时间同步扩散到整个网络以实现全网同步。文中新颖的想法和方法，已经通过系统的分析和仿真得到了研究和证实，显示了算法的可行性。