Performance Evaluation of Non-Terrestrial IAB Nodes at Varying Altitudes in Dense Urban Environments

Abstract

The rise of data-intensive applications in Fifth-Generation (5G) mobile networks demands that next-generation mobile systems deliver seamless, high-bandwidth, and immersive services with improved quality of service. To address these challenges, the use of Integrated Access and Backhaul (IAB) nodes operating over millimeter-wave frequency bands onboard Unmanned Aerial Vehicle (UAV) presents a promising solution. The UAV-mounted IAB network has the potential to enhance line-of-sight conditions to the donor Base Station (BS) via the backhaul link, enabling temporary high data rates in mission-critical and emergency response communication scenarios that require a rapid deployment of new network elements for boosting cellular coverage. This article proposed a framework that integrates terrestrial IAB nodes, non-terrestrial UAV-mounted IAB nodes, and terrestrial donor BS, operating in a dense urban Manhattan-like environment. The research work primarily focuses on how variations in UAV-mounted IAB altitudes, donor BS down-tilt angle, and IAB antenna configuration influence the downlink end-to-end (E2E) spectral efficiency performance of mobile users. Simulation results demonstrate that significant performance gains can be achieved when non-terrestrial IAB nodes are deployed at suitable altitudes when equipped with appropriate antenna configurations. These improvements are further improved when the donor BS employs properly adjusted down-tilt angles, enabling the hybrid terrestrial-aerial IAB mobile network to operate more efficiently and deliver enhanced E2E performances.