基于IEEE 802.1AS的多跳时钟同步算法与系统实现

Multi-Hop Clock Synchronization Algorithm and System ImplementationBased on IEEE 802.1AS

针对现有IEEE 802.1AS协议中单一主时钟无法保障多跳网络下高精度同步的问题,提出一种基于多属性决策的冗余时钟同步方法.首先,基于链路拥塞程度、节点拓扑属性和时钟源质量系数对时钟属性值进行建模;其次,采用多属性决策算法选取最佳主时钟并生成冗余时钟序列表;最后,利用FPGA(Field Programmable Gate Array)平台设计并实现冗余时钟同步系统,同时搭建真实网络环境对所提方法进行测试.结果表明,相较于现有方法,时钟同步精度提升了68%,主时钟失效后重新同步所需收敛时间减小了60%.

Aiming at the problem that a single master clock in the existing IEEE 802.1AS protocol cannot guarantee the high precision of clock synchronization in multi-hop network,a redundant clock synchronization method based on multiattribute decision-making is proposed.Firstly,the clock attribute value is modeled based on the link congestion degree,to⁃pology attribute of node and clock source quality factor.Secondly,the multi-attribute decision-making algorithm is used to select the best master clock and generate a redundant clock sequence table;Finally,the redundant clock synchronization sys⁃tem is designed and implemented on field programmable gate array(FPGA)platform,and a real network environment is constructed to test the proposed method.The results show that,compared with the existing methods,the clock synchroniza⁃tion accuracy is improved by 68%,and the convergence time required for resynchronization after master clock failure is re⁃duced by 60%.