CLONETS-DS Clock Network Services-Design Study Strategy for clock services over optical-fibre networks

The precise time and frequency transmissions based on optical fibre have evolved recently. The time and frequency transfer methods by GSSN are becoming gradually obsolete, definitely providing lower measurements than we can do. Yet, we do struggle with the best effotrt to enable clock comparison, and to utilize the experience with the fibre. An optical clock, they will need to be connected to others, so the collaboration is essential. We present here the further development of infrastructure in mentioned research field. And the synergy of shared entities like QKD, relativistic geodesy, any industrial and societal applications within the shared fibre, where we have been focused on.

1. Introduction

Nowadays, national time and frequency dissemination networks are being developed in many countries. International connections are also being established. However, there is no coherent Pan-European time and frequency dissemination network, which would connect national networks and provide different services based on time and frequency for a wide range of users. The aim of the CLONETS-DS project is to fill this gap. The CLONETS-DS is a European Union-funded research and innovation action intended to facilitate the vision of a sustainable, pan-European optical fibre network for precise time and frequency reference dissemination, by bringing together expertise from national metrology institutes (NMI), academic groups and research infrastructures (RI), research and education networks at the national and European level (NREN, GÉANT) and innovative high-tech small and medium enterprises (SME).