Mobility Management of Multi-hop Mobile Integrated Access and Backhaul Network

As services and applications utilizing mobile networks grow exponentially, base station (BS) density becomes increasingly dense. There is an increasing demand for wireless backhaul technology for efficient deployment of high-density mobile networks. Although integrated access and backhaul (IAB) technology for efficient operation of wireless backhaul is attracting attention, consideration for mobile IAB (MIAB) is very insufficient. In this work, we propose a novel handover (HO) scheme for MIAB network to reduce handover interruption time (HIT) and radio link failure (RLF) that have a significant impact on users' quality of service (QoS). We investigate HO cases that cover intra-gNB HO, inter-gNB HO, and parent MIAB node HO, and develop their probabilistic models according to the velocities of parent MIAB node and child MIAB node. In addition, we investigate the latency in uplink (UP) control plane (CP) data transmission and each HO case for the baseline MIAB network. Our proposed HO scheme consists of low-latency UL CP data transmission with semi-persistent resource preallocation and RACH-less HO procedure for child MIAB nodes. Through simulation, we verify our proposed MIAB HO scheme outperforms the baseline HO scheme in terms of HO delay and HO overhead.