IAB Node Migration Sequencing for Downstream Command Delivery

Solution Overview

Problem

In an integrated access backhaul (IAB) system, when the uppermost-stream IAB node migrates to a target network before downstream nodes, the source CU cannot transmit migration commands to these downstream nodes, preventing them from migrating to the target network.

Innovation Solution

A network migration method where a first IAB node implements a migration procedure based on a received first migration command only after confirming that a target migration command has been transmitted to its downstream child nodes or UE, ensuring all necessary commands are forwarded before initiating its own migration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the uppermost-stream IAB node migrates to the target network before downstream nodes, then the migration speed of the uppermost node is improved, but the source CU cannot transmit migration commands to downstream nodes, causing migration failure

Engineering Contradiction:

Improvemigration speed of uppermost-stream IAB nodeVSAvoidmigration completion of downstream nodes

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The IAB node performs preliminary actions by storing migration commands received from the source CU before migrating to the target network. This allows the node to have migration commands ready for downstream nodes, ensuring they can be transmitted even after the uppermost node has completed its migration. The node executes the migration procedure only after confirming downstream nodes have received their commands, preventing migration failure.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the uppermost-stream IAB node waits for all downstream nodes to migrate first, then migration coordination is improved, but the overall migration time increases

Engineering Contradiction:

Improvemigration coordinationVSAvoidoverall migration time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The IAB node performs preliminary actions by storing migration commands received from the source CU before migrating to the target network. This allows the node to have migration commands ready for downstream nodes, ensuring they can be transmitted even after the uppermost node has completed its migration. The node executes the migration procedure only after confirming downstream nodes have received their commands, preventing migration failure.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12507127B2Network migration method, network migration apparatus, communication device, and communication system

Publication Date: 2025.12.23 VIVO MOBILE COMM CO LTD

AI summary

A network migration method, a network migration apparatus, a communication device, and a communication system. The method includes: implementing a migration procedure of a first IAB node according to a received first migration command in a case that a target migration command has been transmitted to a target network node, where the target network node is a downstream child IAB node of the first IAB node or UE served by the first IAB node in an IAB network, the target migration command includes migration commands corresponding to all downstream network nodes of the first IAB node in the IAB network, and the first migration command is a migration command corresponding to the first IAB node.