Time Transmission System Of Using Bi-contrast Methods In Optical Fiber

With the development of technology,the complexity of the system tends increasingly huge.Many systems composed of multiple subsystems which distributed different locations,then how to synchronize the time in this multiple subsystems is a very meaningful research.There are many ways Co achieve time synchronization,now used more often is Satellite navigation timing system including GPS timing and Bei-Dou timing system.But the satellite time system is not only limiled to the orbital frequency resources,construction of a complex environment,but also limited to non-sovereign property of outer space,these factors inducced us combined with our national conditions to study a lime-frequency networks that having a certain ability to resist destruction and anti-jamming,the fiber time service method undoubtedly met this demand.Firstly this paper described the development of time unified system,studied different types of time services methods in time unified system,compared the pros and cons of these methods,and explained time service's type,method and principle.This article focuses on the optical network time service of SDH and optical network time service using WDM technology.System components scheme of fiber timing using bi-contrast method are proposed,we selected the appropriate device including PC.PCI-GPIB control board,FPGA circuit boards equipped with high-stability crystal,single fiber bi-directional transceiver,high-precision time interval counter,signal-mode fiber builded hardware platform of time transmission system in optical net.Using VC++ tools in windows platform,control software are developed,software realizced the counter data collection using PC.visualization window and automation control of the entire hardware system.With the using of control software,the delay of various parts of the device in optical timing system arc measured,experiment results verify the thcoretical analysis,the article concludes a taming of clock module's design solution based on optical transmission system end achieves the nanosecond level's time service.