RESTART “RESearch and innovation on future Telecommunications systems and networks, to make Italy more smart (RESTART)” program, funded by the European Union under the Italian National Recovery and Resilience Plan (NRRP) of “NextGenerationEU” is a comprehensive program, which brings together and integrates the main stakeholders Italian telecommunications sector, allowing the realization of specific research projects, with concrete and measurable results, to jointly by universities, research centers, and public administrations, within a global framework that includes a long-term vision, transversal actions and support, and adequate tools and facilitators. Within the framework of the RESTART partnership on “Telecommunications of the Future”, the Politecnico di Bari coordinates the structuring project Spoke 2 “Networks integrated terrestrial non-terrestrial” (ITA/NTN). The ITA NTN project is focused on a 6G-oriented scenario, where space network entities (such as low-Earth orbit mega-constellations of nano-satellites, high-altitude platforms, and unmanned aerial vehicles) cooperate with terrestrial networks to provide a 3-dimensional (3D) wireless connectivity. Indeed, it targets the ambitious goal of conceiving novel methodologies and effective solutions able to provide pervasive, ubiquitous, and flexible 3D on-demand wireless broadband connectivity and edge computing services through the effective integration of Terrestrial (T) and Non-Terrestrial (NT) wireless networks. To this end, various research activities will be planned to cover architectural aspects, protocols, and functionalities operating at the different levels of the communication stack (including the physical layer), and orchestration algorithms. While considering the reference guidelines related to beyond-5G and 6G roadmap (i.e., NetWorld 2020 Strategic Research and Innovation Agenda 3GPP documents, EU initiatives targeting 2030 Digital Decade objectives and EU Global Gateway strategy, ongoing ESA Calls, and industry white papers), ITA NTN will particularly consider the peculiarities of heterogeneous uses cases.

More specifically, ITA NTN introduces five main project goals, as defined in what follows.

• Goal 1: ITA NTN will design a 3D multi-layered communication architecture for integrated terrestrial/non-terrestrial networks to support high-capacity applications and massive access by heterogeneous devices.
• Goal 2: Evaluate the link budget of free-space, optical, and radiofrequency communication links in a 3D multi-layered communication architecture by investigating and developing technologies related to optical internode communications.
• Goal 3: Design advanced transmission techniques for integrated terrestrial/non-terrestrial networks based on novel antennas, electronic technologies, waveforms, multiple access techniques, and MIMO schemes.
• Goal 4: Create innovative methodologies for dynamic, energy-efficient, and QoS/QoE-aware orchestration of communication and computational resources exposed in a 3D multi-layered communication architecture. This can be achieved by leveraging NFV, SDN, and Network slicing principles, as well as MEC technology.
• Goal 5: Evaluate the performance of conceived approaches in reference use cases through computer simulations and Proof of Concepts to assess network coverage synergy, coexistence issues, and operational impairments.