传感器网络中基于延迟测量的时间标记  

Time Stamping Based on Delay Measurement in Sensor Networks

作　　者：陈建荣[1] 童洪亮[1] 朱培栋[1] 齐治昌[1] 

机构地区：[1]国防科技大学计算机学院,湖南长沙410073

出　　处：《计算机工程与科学》2008年第2期84-86,127,共4页Computer Engineering & Science

基　　金：国家863计划资助项目(2005AA121570);预研基金资助项目(51415040205KG0151)

摘　　要：传感器网络许多应用需要对数据进行时间标记,用来记录数据的产生时间,从而实现报文调度和其他时间相关操作。本文提出了一种不需要时间同步的标记方法,该方法使用时间戳记录报文从产生到报文到达目的节点所经历的时间,从而使得目的节点能够通过本地时钟和时间戳中的时间间隔得到报文产生的相对时间。该方法的主要误差来源于无线通信延迟的不确定性,为此,我们采用基于测量的估计方法确定这种延迟,并进行误差补偿。分析表明,这种时间标记方式和维护全局时钟相比不仅开销更小,并且精度较高。使用UCBerkeley基于TinyOS系统的Micaz节点进行实验表明,多跳网络应用的误差平均每跳不超过一个时钟周期。In many sensor network applications, data need tune stamps to record me moment of prooucmg me uata. Time stamps are indispensable for packet scheduling and other time-related tasks. The paper proposes a method of time stamping without the requirement of time synchronization. The time stamp of a datum records the time span from the moment when the data is produced to the moment it arrives at the destination. The destination node of a datum can obtain the moment of the datum＇s production by its clock of the datum＇s arrival minus the time stamp on the datum. In the proposed method,the inaccuracy of the time record mainly comes from the indeterminate wireless communication delay. Estimation based on the measurement of communication delay is used to compensate the inaccurate time record. Theoretical analysis proves that the method is superior to the existing methods on both expense and accuracy. Our experiments on UC Berkeley Micaz within the TinyOS framework show that the time stamp method can achieve the average accuracy of one clock tick per hop in multiple-hop sensor networks.

关 键 词：传感器网络 时间标记 延迟测量 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]