On Integrated Access and Backhaul Networks: Current Status and Potentials

TL;DR

This paper reviews the current status, protocol developments, and performance evaluation of integrated access and backhaul (IAB) networks for 5G, highlighting their potential for network densification and robustness under various conditions.

Contribution

It provides a comprehensive analysis of IAB networks, including protocol layer discussions, performance modeling with stochastic geometry, and robustness assessments under environmental factors.

Findings

IAB networks can effectively support 5G densification.

Performance varies with deployment conditions and environmental factors.

IAB networks show robustness to weather and blockage effects.

Abstract

In this paper, we introduce and study the potentials and challenges of integrated access and backhaul (IAB) as one of the promising techniques for evolving 5G networks. We study IAB networks from different perspectives. We summarize the recent Rel-16 as well as the upcoming Rel-17 3GPP discussions on IAB, and highlight the main IAB-specific agreements on different protocol layers. Also, concentrating on millimeter wave-based communications, we evaluate the performance of IAB networks in both dense and suburban areas. Using a finite stochastic geometry model, with random distributions of IAB nodes as well as user equipments (UEs) in a finite region, we study the service coverage rate defined as the probability of the event that the UEs' minimum rate requirements are satisfied. We present comparisons between IAB and hybrid IAB/fiber-backhauled networks where a part or all of the small base stations are fiber-connected. Finally, we study the robustness of IAB networks to weather and various deployment conditions and verify their effects, such as blockage, tree foliage, rain as well as antenna height/gain on the coverage rate of IAB setups, as the key differences between the fiber-connected and IAB networks. As we show, IAB is an attractive approach to enable the network densification required by 5G and beyond.