Architectural analysis and performance evaluation of Integrated Access-Backhaul Non-Terrestrial Networks

Abstract:
The growing attention devoted to the wireless backhauling and relaying capabilities of 5G networks, and the related satellite link integration is testified in the latest releases of 3GPP 5G standards. Both these aspects are essential to guarantee interoperability and integration of relays from different vendors, as well as to benefit from the economies of scale of 3GPP technologies by satellite ecosystems, lowering costs of 5G network implementations and satellite connectivity. Nevertheless, the adoption of a satellite link characterizing the non-terrestrial network implies a series of issues and protocol adaptations, mainly due to the high propagation delay. This holds true especially for the backhaul link, that must guarantee service continuity, reliability, and availability. There have been some studies in the recent past that analyzed the protocol adaptations needed for a satellite link, but they were conducted in the context of 4G networks, and only for the access network. To bridge this gap, this paper analyzes 5G non-terrestrial networks with satellite backhaul links, proposing some key architectures and the related protocol adaptations. A satellite link analysis and a system-level throughput evaluation are also carried out in some reference scenarios, considering the most recent 5G-related aspects to assess the effective utilization of satellites in new integrated terrestrialsatellite network scenarios.