RadioNet is an I3 that coordinates all of Europe’s leading radio astronomy facilities in an integrated cooperation to achieve transformational improvement in the quality and quantity of the scientific research of European astronomers. RadioNet3 includes 27 partners operating world-class radio telescopes and/or performing cutting-edge R&D in a wide range of technology fields important for radio astronomy.RadioNet3 proposes a work plan that is structured into 6 NAs, 7 TNAs and 4 JRAs with the aim to integrate and optimise the use and development of European radio astronomy infrastructures. The general goals of RadioNet3 are to:- facilitate, for a growing community of European researchers, access to the complete range of Europe’s world-leading radio-astronomical facilities, including the ALMA telescope;- secure a long-term perspective on scientific and technical developments in radio astronomy, pooling resources and expertise that exist among the partners;- stimulate new R&D activities for the existing radio infrastructures in synergy with ALMA and the SKA;- contribute to the implementation of the vision of the ASTRONET Strategic Plan for European Astronomy by building a sustainable and world leading radio astronomical research community.RadioNet3 builds on the success of two preceeding I3s under FP6 and FP7, but it also takes a leap forward as it includes facilitation of research with ALMA via a dedicated NA, and 4 pathfinders for the SKA in its TNA Program. It has a transparent and efficient management structure designed to optimally support the implementation of the project.RadioNet is now recognized by funding agencies and international project consortia as the European entity representing radio astronomy and facilitating the access to and exploitation of excellent facilities in this field. This is of paramount importance, as a dedicated, formal European radio astronomy organisation to coordinate and serve the needs of this community does not yet exist.