6G Integrated Access and Backhaul Networks with Sub-Terahertz Links

Integrated Access and Backhaul (IAB) is a flexible and low-cost solution to deploy ultra-dense fifth and sixth generation (5G and 6G) systems, as it enables wireless backhaul links based on the same technology and specifications as for the access links. In this paper, we consider the deployment of mixed millimeter wave (mmWave) and sub-terahertz links to increase the capacity of the backhaul network, and provide the first performance evaluation of the potential of sub-terahertz frequencies for 6G IAB. To do so, we develop a greedy algorithm that allocates frequency bands to the backhaul links (considering constraints on spectrum licenses, sharing, and congestion) and generates the wireless network mesh. We then profile the performance through a custom extension of the open-source system-level simulator Sionna that supports Release 17 IAB specifications and channel models up to 140 GHz. Our results show that IAB with sub-terahertz links can outperform a mmWave-only deployment with improvements of 4×for average user throughput and a reduction of up to 50% for median latency.