| 摘要: |
| 异地站点之间需要在广域范围实现时间同步。除了采用卫星授时外，希望借助SDH（Synchronous Digital Hierarchy）网络进行时间同步性能的在线监测。但是广域范围内的SDH网络结构复杂、跳数较多，且大量存在上下行线路不对称的现象，对传统网络时间同步技术提出了挑战。因此，针对广域SDH网络，提出了基于WR PTP（White Rabbit Precision Timing Protocol）技术的链路模型。该模型考虑了SDH网络中存在的各个延时环节及其计算方法，并针对实际网络中存在的不对称链路时延，给出了修正方法，推导了时钟偏差的修正计算公式。同时对于SDH环网中存在的链路倒换问题，给出了工程化解决方法。所提各方法在实际的SDH网络上进行了测试，结果表明，能达到的时间同步误差不超过1 μs，可满足广域时间同步及时钟同步性能在线监测的需要。 |
| 关键词: 时间同步 在线监测 SDH网络 WR PTP |
| DOI：10.20079/j.issn.1001-893x.240412002 |
|
| 基金项目: |
|
| A Novel Remote Clock Synchronization Technology Based on SDH Network |
| JI Qiang,MENG Linggang,SHI Guoxin,JING Shi,TENG Yunlong |
| (1.Shenyang Aircraft Design and Research Institute,Shenyang 110035,China;2.National Institute of Metrology and Testing Technology,Chengdu 610021,China;3.School of Mechanical and Electrical Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China) |
| Abstract: |
| Time synchronization needs to be achieved across a wide area between remote sites.In addition to using satellite timing,it is hoped to use synchronous digital hierarchy(SDH) network for online monitoring of time synchronization performance.However,the SDH network structure in a wide area is complex,with a large number of hops,and there are many asymmetric uplink and downlink lines,which poses a challenge to traditional network time synchronization technology.Therefore,a link model based on White Rabbit Precision Timing Protocol(WR PTP) technology is proposed,which considers various delay links and their calculation methods in SDH networks.And in response to the asymmetric link delay that exists in actual networks,a correction method is proposed,and a correction calculation formula for clock bias is derived.Meanwhile,engineering solutions have been provided for the link switching problem in SDH ring networks.The methods proposed have been tested on actual SDH networks and the results show that the time synchronization error is no more than 1 μs,so they can meet the needs of online monitoring of time synchronization performance. |
| Key words: time synchronization online monitoring SDH network WR PTP |
