Innovative Multi-Layer Approaches for 6G Integrated Terrestrial and Non-Terrestrial Networks

This paper explores the integration of Terrestrial Networks and Non-Terrestrial Networks (T/NTNs) as a critical enabler for the 6thGeneration (6G) of communication systems. Starting from the 3rdGeneration Partnership Project (3GPP) specifications and roadmap, this article investigates cutting-edge aspects of architectural designs, advanced transmission techniques, and cross-domain management strategies. In particular, in order to address challenges in seamless connectivity and optimized resource utilization, the proposed multi-layer approach combines terrestrial, aerial, and satellite components for improved coverage, scalability, and adaptability. Key and innovative contributions include modular waveform designs, efficient management of free-space optical links, and a comprehensive NTN framework.