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

Published

December 4, 2014

Author(s)

Marc A. Weiss, Lee Cosart, James Hanssen

Abstract

There is a need to back up critical timing infrastructure at the national level. This presentation 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 presentation provides insight into both the planning and validation of the transport path as well as analysis of the experimental data. The focus here is in using a US commercial telecom carrier to transfer time between two national sources 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.

Proceedings Title

Proceedings of 2014 PTTI Meeting

Conference Dates

December 1-4, 2014

Conference Location

Boston, MA

Conference Title

2014 PTTI Meeting

Pub Type

Conferences

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Keywords

critical infrastructure, Precise Time Protocol, Time backup, time transfer through telecom

Citation

Weiss, M. , Cosart, L. and Hanssen, J. (2014), Ethernet Time Transfer through a U.S. Commercial Optical Telecommunications Network, Proceedings of 2014 PTTI Meeting, Boston, MA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=917612 (Accessed October 13, 2025)