Ethernet Time Transfer Through a U.S. Commercial Optical Telecommunications Network

M. Weiss, L. Cosart, J. Hanssen, S. Hicks, C. Chase, C. Brown, C. Allen, P. Johnson, G. Wiltsie, D. Coleman

Abstract:	There is a need to back up critical timing infrastructure at the national level. This paper describes a joint project employing commercial equipment to send national timing signals through a telecommunication network. This experiment connects UTC(NIST) in Boulder, Colorado with UTC(USNO) at the Alternate Master Clock at Schriever AFB via a telecommunication provider's optical network using the Precise Time Protocol (PTP) to compare the time standards. The experiment was started in April 2014 and will run through the end of 2014. The paper provides insight into both the planning and validation of the transport path as well as analysis of the experimental data. The focus here is using a US commercial telecom carrier to transfer time between two national real-time standards of UTC. While many researchers have shown that fiber can transfer time and frequency with high accuracy, this experiment addresses the practicality of using the US telecom infrastructure for timing. Our results thus far show a bias of about 40 microseconds between the two one-way directions of PTP signals, with the best method having a variation of under about 50 nanoseconds peak-to-peak. Research is continuing to determine the cause of the bias.
Published in:	Proceedings of the 46th Annual Precise Time and Time Interval Systems and Applications Meeting December 1 - 4, 2014 Seaport Boston Hotel Boston, Massachusetts
Pages:	214 - 220
Cite this article:	Weiss, M., Cosart, L., Hanssen, J., Hicks, S., Chase, C., Brown, C., Allen, C., Johnson, P., Wiltsie, G., Coleman, D., "Ethernet Time Transfer Through a U.S. Commercial Optical Telecommunications Network," Proceedings of the 46th Annual Precise Time and Time Interval Systems and Applications Meeting, Boston, Massachusetts, December 2014, pp. 214-220.
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