The Potential of Multilayered Hierarchical Nonterrestrial Networks for 6G: A Comparative Analysis among Networking Architectures

Research for 6th generation (6G) communication currently focuses on nonterrestrial networks (NTNs) to promote ubiquitous and ultrahigh-capacity global connectivity. Specifically, multilayered hierarchical networks, i.e., the orchestration among different aerial/space platforms, including low-altitude platforms (LAPs), high-altitude platforms (HAPs), and satellites cooperating at different altitudes, currently represent one of the most attractive technological options to solve coverage and latency constraints associated with the NTN paradigm. However, several issues still need to be resolved for proper network design. In this work, we evaluate the performance of different multilayered nonterrestrial configurations. We also provide guidelines on the optimal working point(s) for which it is possible to achieve a good compromise between improved system flexibility and network performance with respect to a baseline stand-alone deployment.