Enhancing QoS in 6G Networks Through Multi-IAB Relaying Strategies With Optimal Path Selection

The rapid increase in global data traffic requires a new generation of mobile communication technologies to enable seamless and immersive high bandwidth services, with improved Quality of Service (QoS), to the end-user terminals. To achieve this goal, the combination of Millimeter Wave (mmWave) links with Integrated-Access-and-Backhauling (IAB) technology, offers a promising solution. With IAB, the wireless Backhaul Link (BL) between donor Next Generation Node B (gNB) and IAB nodes simplifies the ultra-densification of network elements, reducing the cell sizes and increasing the chances of having a Line-of-Sight (LoS) condition in the last wireless hop towards the User Equipment (UE), which is known as an Access Link (AL). This paper studies the end-to-end (e2e) data rate performance of an IAB-enhanced cellular network deployed in a Manhattan-like urban setting, proposing an optimal path selection scheme to improve the experience of mobile users in dense urban environments. This selection scheme allows a mobile UE to connect to a gNB or an IAB node, ensuring improved Signal-to-Interference-and-Noise-Ratio (SINR) levels and, consequently, higher e2e data rates. Simulation results show notable improvements with the optimal path selection scheme, achieving data rate gains of 4.9-6.6 bps/Hz at the 50th percentile, across various IAB relaying strategies when using mmWave frequency bands with a few hundred MHz of bandwidth. This study emphasizes the significance of mmWave IAB deployments in dense urban areas, with optimized path selection to improve end-user experience in dense urban scenarios in which the probability of LoS condition reduces notably with distance even in small cell network deployments.