Timing and Synchronization Networks 

Timing & Synchronization Standardization: ITU-T and IEEE

Primary Reference Clocks 
Primary Reference Time Clocks
ePRC - PRTC - ePRTC - cnPRTC

 Boundary Clocks - SyncE

 High-Accuracy Time Transfer

 GNSS - UTC(k)  

Timing & Synchronization Testing 

Links:
https://ieeexplore.ieee.org/author/37085811147
https://www.linkedin.com/in/helmut-imlau-13805558/
https://www.researchgate.net/profile/Helmut-Imlau-2