Fiber optic time transfer between PTB and Deutsche Telekom using multi-link redundant topology

We report on the upgrade of a fiber optic network for time and frequency transfer between PTB in Braunschweig and the test center of Deutsche Telekom in Bremen, Germany. The network provides 10 MHz and 1 PPS signals at remote locations intended for the supervision of the mobile telecommunication network of Deutsche Telekom. Here we present the results of the time transfer calibration of the link.