二层拓扑结构的Zigbee时间同步算法

为了解决大规模无线传感器网络中同步误差随跳距的累积问题,提出一种基于二层拓扑结构的时间同步算法.首先,通过根节点发送时间同步报文,沿二层拓扑结构从父节点到子节点传递时间同步报文;其次,支配节点根据同步报文到达时刻调整本地时间,更新并发送同步报文;最后,非支配节点根据同步报文到达时刻调整本地时间.依此类推,最终可实现所有节点的时间同步.应用结果表明,在由31个节点组成的无线传感器网络中,该算法的同步开销相比较于RBS算法减少了93%.而引起累积误差的关键路径长度相比较于连通支配集算法减少了50%.

Time Synchronization Algorithm Based on Two-layer Topology for Zigbee Wireless Networks

In order to solve the accumulation of synchronization error over hop distance in large scale wireless sensor networks,A new time synchronization algorithm has been proposed based on two-layer topology.Firstly,time synchronization packet,produced by the root node,is transmitted along two-layer topology from the father node to child node.Secondly,the dominated nodes adjust their local time according to their received packet,and at the same time update the time of packet,then send it to next node.Finally,the non-disposable nodes adjust their local time according to their received packet.All nodes are eventually synchronized through the above way.Practical application has been carried out in a wireless network consisted of 31 sensor nodes.The results show that the synchronization overhead is reduced by 93% compared with RBS algorithms and the length of the critical path which caused the accumulated error is reduced by 50% compared with the minimum connected dominating sets algorithm.