The GN4-3 is the proposed project for the third Specific Grant Agreement under the 68-month Framework Partnership Agreement (FPA) established between the GÉANT Consortium and the European Commission in April 2015. This third phase of implementing the FPA is proposed to last 48 months and is a natural continuation of the work in GN4-2, building on the results and maintaining the overall objective of helping to raise European research to the next level, promoting scientific excellence, access and re-use of research data. GÉANT’s world-class, high-speed backbone provides seamless and secure connectivity with 42 National Research and Education Networks (NRENs), reaching over 50 million users in 10,000 institutions across Europe, and more than 100 countries worldwide through links with other regions. The core backbone is capable of multiple 100 Gbps transmission over each fibre link, and Terabit connectivity can be achieved by a single node. The safe and rapid connection of users to each other, to the increasing amounts of data generated by research, and to the high-performance computing capacity required by collaborative research form the foundation of the GÉANT partnership. GÉANT services offer convenient, fast and reliable access to European High Performance Computing facilities, cloud services for the research and education community, access to scientific data and publications and other services from the European e-infrastructure providers, whenever and wherever needed. The structure of the present proposal emphasises updating existing services in line with requirements of the user community. This complements the proposed companion project GN4-3N, an ambitious programme increasing the footprint of the backbone network at the same time as improving its capacity, resilience and flexibility with the aim of offering 100Gbps network access to many more GÉANT partners and significantly diminish the digital divide.

The GN4 Phase 3 Network (GN4-3N) proposal for part b of the third Specific Grant Agreement (SGA3(b) is made in response to the H2020-SGA-INFRA-GEANT-2018 (Topic [b] Research and Education Networking) call, received 17 October 2018, under the 68-month Framework Partnership Agreement (FPA) established between the GÉANT Consortium and the European Commission in April 2015. It is proposed to last 48 months to implement, as the call requests, a very ambitious restructuring of the backbone network operated by GÉANT in order to provide equal access to clouds and other e-infrastructure services in the European research area and beyond. It will improve the overall resilience and reliability of the GÉANT network significantly and offer a base for future improvements in access, transmission speeds and capacity wherever needed. The outcome of GN4-3N project will offer uniform network access and choice of services to many more partners, eliminating the "digital divide" wherever technically and economically feasible. This project proposal is based on technical and economic studies carried out during 2017-2018 in the GN4-2 project which have given the Consortium clarity on the resourcing, financial and effort, needed to realise the huge ambition of this undertaking. It exclusively covers the engineering, procurement, acquisition and installation of the new backbone network. The day-to-day network operations as the elements of it is commissioned is the responsibility of the teams described in accompanying the GN4-3 project. The GN4-3 and GN4-3N proposals are intimately connected through common teams and the technical, management and procurement expertise built-up over previous GN projects. This is what makes this ambitious proposal realistic. GN4-3N and GN4-3 have simply had to be proposed as distinct projects, due to the different funding model (with no depreciation) to be used in GN4-3N project.

In recent years Cloud Services for Synchronization and Sharing (CS3) have been widely deployed in the research and educational space. The services are operated and funded by major e-infrastructure providers, NRENs (National Research & Education Networks) and major research institutions. The CS3 services have become successful on a national level at the scale of individual institutions and started becoming an indispensable element of daily workflows for hundreds of thousands of users including researchers, students, scientists and engineers. The community deploying these services grew bottom up and found its home at the yearly CS3 conferences (cs3.cern.ch). However, these services remain largely disconnected, and they are developed and deployed in isolation from each other. At the current state of maturity and community uptake however, combining these various systems and services would allow to boost open-science by presenting a joint, coordinated service to the users in the research and education space on a pan-European level. CS3MESH4EOSC implements a service for the European Open Science Cloud (EOSC) with a built-in sustainability model using the on-premise service delivery by utilizing existing key technology enablers: Open Cloud Mesh (OCM) standardized protocol and EduGAIN service. It consolidates and integrates the existing application ecosystem by promoting vendor-neutral APIs and protocols following the open-source strategy for delivering services -- a platform for a thriving application ecosystem in EOSC. CS3MESH4EOSC empowers service providers in delivering state-of-the-art, connected infrastructure to boost effective scientific collaboration across the entire federation and data sharing according to FAIR principles.The project delivers the core of a scientific and educational infrastructure for cloud storage services in Europe through a lightweight federation of existing sync/share services and integration with multidisciplinary application workflows.