Time transfer using frame detection in fiber-optical communication networks: New hardware

In this paper, a new, recently developed hardware for time transfer using passive listening and detection of SDH frame headers in fiber-optical networks is described. The method has been presented earlier, and results, using prototype equipment and an experimental fiber-link, have shown that time transfer with a precision of a few nanoseconds is possible over links with network distances exceeding 500 km. In order to further develop the method and make it available to regular users of time keeping equipment, it has been essential to minimize the space requirements of needed hardware and to make the implementation and installation more easily and straight forward.