IEEE1588v2时间同步原理及应用浅析

Analysis on IEEE1588v2 Time Synchronization Principles and Application

文章介绍了IEEE1588v2的基本概念,将IEEE1588v2与常用的时间同步方案进行了分析比较。分别对BC+OC、E2E TC+OC和P2P TC+OC这3种基本的IEEE1588v2时间同步模型的工作原理进行深入的分析,对3种模型的时间同步过程进行详细计算。通过分析和计算表明:(1)BC+OC模型支持层次化的同步结构,符合传统的同步网络部署方式;存在误差累积效应,在时间同步链路中,串接的BC数量不宜过多;(2)E2E TC+OC模型支持高精度多跳网络部署;采用星型网络结构,可避免时钟成环,安全可靠性高;不支持分层规划,所有SC都跟踪到GMC,GMC的压力较大,不适合构建大型网络;(3)P2P TC+OC模型支持高精度大范围多跳网络部署;采用星型网络结构,可避免时钟成环,安全可靠性高;GMC的压力小,适合构建大型网络。随着承载网向PTN、OTN网络演进,IEEE1588v2在铁路时间同步网中的应用条件开始逐步成熟,可以分层、分步推进。同时,根据各种时间同步模型特点,提出了分层建设网络模型。

In this paper, the basic concepts of IEEE1588v2 is introduced, meanwhile IEEE1588v2 and the frequently used time synchronization solution are analyzed and compared. The working principle of three kinds of basic IEEE1588v2 time synchronization models including BC＋OC, E2E TC＋OC and P2P TC＋OC is analyzed in depth. And time synchronization process of three kinds of models is calculated in detail. The analysis and calculation show, BC＋OC model supports hierarchical synchronous structure, consistent with the traditional synchronous network deploy-ment;there exists error accumulation effect, so the number of tandem BC should not be too much in the time synchroni-zation link. E2E TC ＋ OC model supports high-precision multi-hop network deployment, and uses the star network structure with high safety and reliability, which can avoid the clock loop. E2E TC＋OC model does not support layered planning, all SC are tracked to GMC leading to GMC’s greater pressure. So E2E TC ＋OC model is not suitable for building large networks. P2P TC＋OC model supports high-precision large-scale multi-hop network deployment, and u-ses the star network structure with high safety and reliability, which can avoid the clock loop. GMC’s pressure is rela-tively small, so P2P TC＋OC model is suitable for building large networks. Along with the evolution of the bearer net-work to PTN and OTN, the application conditions of IEEE1588v2 in railway time synchronization network have gradually matured, it can be advanced hierarchically and gradually. According to the characteristics of different time synchroniza-tion models, layered construction of network model is put forward. This paper has a certain guiding significance for the high-precision time synchronization system engineering design.