SDH网络时钟频偏的检测方法研究

Research on Test Method for Clock Frequency Offset of SDH Network

根据SDH系统指针调整事件与网络时钟同步性能的相关性,进行理论分析和量化计算,获得管理单元和支路单元指针数值与时钟同步性能(频偏)的线性相关性,建立了相应的数学模型,并将理论计算值与仪表实际测试结果进行对比验证,获得预期的一致性.在此基础上,提出一种在网络运行环境下新的实用作业方法,即查询SDH网管的指针调整计数值,通过本文提供的数学模型及方法,可以准确获知网络时钟频偏值.该方法便捷实用,可以部分替代昂贵的专用仪表,及时发现网络中同步性能超标问题,从而更好地保证网络的运用质量.

As for the correlation between the pointer adjustment event in the SDH system and the performance of network clock synchronization,theoretical analysis and quantitative calculation are made to obtain the linear dependence of the administrative unit and tributary unit's pointer values and the performance(frequency offset)of clock synchronization.Meanwhile,a mathematical model is established and calculated results of the model are compared to actual test results for verification,attaining the conclusion as expected.Based on this,a practical operation method in network environment is put forward.that is the frequency offset value of network clock can be calculated accurately by querying the pointer adjustment count value of SDH network administration and using the mathematical model and the operation method.This method is convenient and practical and can partly replace expensive special-purpose instrument in detecting excessive clock synchronization performance of the network timely,thus better ensuring the operation quality of the network.