Time and frequency transfer system for synchronization applications

In this paper, we propose a new generation of time and frequency transfer system using Global Navigation Satellite System (GNSS) dual frequency receiver for the purpose of both time and frequency synchronization. The system can be used as a timing source, remote time and frequency calibration, and to monitor the characteristic of the telecommunication primary reference clocks (PRC). A series of experiments were conducted to evaluate the performance of the system. The common-view common-clock test was studied for the evaluation of the system noise level. The tests of short-baseline about 20 km between Chunghwa Telecommunication Laboratories (TL) and telecommunication facilities, and long-baseline around 10,000 km between TL and MSL (Measurement Standards Laboratory, New Zealand) were performed. Experimental results indicate that expanded time and frequency uncertainty of the proposed system (with a coverage factor of k=2) are less than 26 ns and 1.1×10^-13 (one day averaging), respectively, which can meet ITU-T G.811 standard approximately and requirements for the dominant telecommunication and power system synchronization applications.