Robust and Resilient Terrestrial–Non-Terrestrial Connectivity for In-Flight Connectivity in the Beyond-5G/6G Era

The integration of terrestrial and non-terrestrial networks is essential for reliable, secure, and ubiquitous connectivity with QoS guarantees, and is a key enabler for supporting emerging applications like in-flight broadband connectivity and mission-critical operations, though several challenges remain. This paper compares three architectural options for providing in-flight broadband connectivity: a DU/CU functional split with the DU on the aircraft and the CU on the ground; a similar split enhanced with integrated access and backhauling to enable 3GPP-compliant flying ad-hoc networks; and a novel architecture in which aircraft act as mobile wireless access and backhaul nodes hosting MEC capabilities for low-latency services and local breakout, a flexible approach that requires sophisticated SON functions and optimised routing.