A Scalable Communication Model to Realize Integrated Access and Backhaul (IAB) in 5G

Our vision of the future world is one wherein everything, anywhere and at any time, can reliably communicate in real time. 5G, the fifth generation of cellular networks, is anticipated to use heterogeneity to deliver ultra-high data rates to a vastly increased number of devices in ultra-dense areas. Improving the backhaul network capacity is one of the most important open challenges for deploying a 5G network. A promising solution is Integrated Access and Backhaul (IAB), which assigns a portion of radio resources to construct a multi-hop wireless backhaul network. Although 3GPP has acknowledged the cost-effectiveness of the IAB-enabled framework and its orchestration has been extensively studied in the literature, its transmission capacity (i.e., the number of base stations it can support) has not been sufficiently investigated. In this paper, we formulate the problem of maximizing transmission capacity and minimizing transmit powers for IAB-enabled multi-hop networks, taking into account relay selection, channel assignment, and power control constraints. Then, the solution space of the problem is analyzed, two optimality bounds are derived, and a heuristic algorithm is proposed to investigate the bounds. The claims are finally supported by numerical results.