Two-way optical time and frequency transfer between IPE and BEV

This paper describes our experience with long term two-way optical time transfer between Czech and Austrian national time and frequency laboratories maintaining their national time and frequency standards generating the national time scales UTC(TP) and UTC(BEV), respectively. The optical link utilizes either dedicated optical fibers or Dense Wavelength Division Multiplex (DWDM) channels in all-optical production telecommunication networks. Results from the optical transfer, i.e. clock comparison and link delay including diurnal and seasonal effects are shown and also compared with GPS Common-View and Precise Point Positioning.