Time & Frequency Distribution over Optical link

demetra Time & Frequency Distribution over Optical link

Time and Frequency dissemination with the best accuracy and stability and extreme resilience to external perturbations.


A time signal referenced to INRIM is disseminated using optical fibers. Different architectures and different techniques are available to meet user needs. An accuracy beyond the GPS level can be achieved through open source techniques (White Rabbit) and the more innovative Modulated Coherent Time (MCT).

Features and benefits

Advanced Timing provision with best accuracy and stability
Superior resilience to interference and attacks to ensure safety requirements and integrity.

How it works

The reference time signal generated at INRIM is encoded by modulating the amplitude of a laser radiation, then routed on a commercial optical fiber network. The user is equipped with a receiver that demodulates the incoming light generating a set of useful reference signals for time stamping and frequency reference (1PPS and 10 MHz). The accuracy of the time reference is better than 1 ns with respect to the INRIM timescale UTC(IT). A set of Key Performance Indicators monitors the system and the performances at the user-end.

Time Service Details

Version: 1.0

Company: INRIM - Istituto Nazionale di Ricerca Metrologica

Address: Strada delle Cacce 91, 10135, Torino- Italy

Contact with the company: email us

Website: rime.inrim.it/H2020-Demetra



This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640658. The Commission is not responsible for any use that may be made of the information this web contains.


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Our Office

Strada delle Cacce, 91,
10135 Torino, Italy.
e-mail: info@demetratime.eu