Conditional Handover in IAB Wireless Backhaul Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless relay networks face challenges in maintaining reliable wireless backhaul links, particularly in edge areas where signal quality is weak, leading to performance issues like reduced data rates and high link failures, and existing methods lack effective solutions for conditional handovers during unfavorable conditions.
Innovation Solution
The implementation of a wireless terminal and IAB node system that communicates through an IAB donor, using node serving cell information and backhaul radio link condition indications to determine conditional handovers, enabling autonomous handovers and redundant connection management to maintain network stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If relay nodes are deployed to expand coverage area, then coverage area is increased, but link failure probability increases due to weak backhaul signals at edge areas
Solution Approach 1:
The network configures conditional handover parameters in advance for relay nodes before handover is needed. When backhaul link quality degrades, the relay node can immediately execute the pre-configured handover to a target cell without waiting for handover commands, thereby maintaining connection reliability while extending coverage to edge areas.
2Reliability
If conditional handover is enabled for relay nodes, then link reliability is improved, but signaling overhead and handover complexity increase
Solution Approach 1:
The relay node autonomously monitors its own backhaul link quality and independently decides whether to trigger conditional handover based on pre-configured thresholds. This self-service mechanism eliminates the need for continuous network control signaling during handover decisions, reducing signaling overhead while maintaining reliable handover execution.
3Speed
If autonomous handover decision is implemented at wireless terminal, then handover speed is increased, but handover accuracy may deteriorate due to limited terminal knowledge of network conditions
Solution Approach 1:
The relay node acts as an intermediary between the network and the wireless terminal. It receives conditional handover configurations from the network, monitors backhaul link quality, and makes autonomous handover decisions based on both network-provided parameters and its own measurements. This intermediary role enables fast autonomous handover while maintaining accurate decision-making through combined information.
Data Source
AI summary
A wireless terminal communicates with an Integrated Access and Backhaul (IAB) donor via an IAB node. The wireless terminal comprises receptacle and processor circuitry. The receiver circuitry is configured to receive: node serving cell information indicating one or more cells served by the IAB node; a reconfiguration message comprising a conditional reconfiguration, the conditional reconfiguration further comprising at least one identity of a target candidate cell, and; a backhaul (BH) radio link condition indication. The processor circuitry is configured, upon receiving the BH radio link condition indication, to determine whether to trigger a conditional handover configured by the conditional reconfiguration based on the node serving cell information. Methods of operating such wireless terminals are also provided.