Mobile Integrated Access and Backhaul Node Backhaul Link Failure Recovery with Conditional Handover

Mobile integrated access and backhaul (IAB) has become an important topic and potential technology to discuss beyond the fifth generation (B5G) because the mobility of IAB nodes seriously affects the performance of networks and results in frequent backhaul radio link failure (BH RLF). In this paper, to recover from backhaul failures, we consider methods using the advanced preparation of alternative backhaul links and routes, such as conditional handover (CHO), to recover from backhaul failures. We propose two solutions to this issue, including cell selection based on parameter prediction and preconfigured priority and a force trigger CHO event in different scenarios. When RLF occurs in the mobile IAB nodes own BH links, the priority of the CHO candidate cell should be increased, effectively improving the selection probability of CHO candidate cells. When RLF occurs in the mobile IAB nodes' parent BH link, we propose a new CHO trigger event to ensure that when its own link is intact, CHO will be triggered. Through theoretical analysis, we show that our solutions effectively reduce backhaul link failure.