Time and frequency transfer in modern DWDM telecommunication networks

In the paper the authors present their experiments oriented on transferring time and frequency signals over modern telecommunication networks carrying 40/100 Gbps signals using coherent techniques. The experiments were performed in 1500 km-long loop arranged by PSNC in the PIONIER production network. We observed good stability of delivered signals: Modified Allan Deviation of 10
^-15
at 10
³
s averaging (for 10 MHz frequency signal), and Time Deviation below 10 ps for averaging up to 10
⁵
s for 1 PPS time signal.