IAB Relay Cell Selection Under Barred Cell Load Conditions

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Solution Overview

Problem

In cellular communication systems with Integrated Access and Backhaul (IAB) nodes, existing methods for cell selection by relay nodes are inefficient, leading to potential interference and network load issues when barred cells are heavily loaded, as relay nodes ignore or follow conflicting information elements regarding cell selection.

Innovation Solution

The method involves transmitting specific information elements to relay nodes and user equipment, allowing relay nodes to ignore or follow certain information elements based on their barred status, ensuring coordinated cell selection and reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cell selection is barred to control network load and interference, then network stability is improved, but relay nodes cannot perform relay communication in the cell

Engineering Contradiction:

Improvenetwork stabilityVSAvoidrelay communication capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies different cell selection rules to different node types. User equipment follows the cellBarred indication strictly, while relay nodes ignore the cellBarred indication and cell selection is determined by intraFreqReselection parameters. This local differentiation allows relay nodes to maintain communication capabilities even when cells are barred for regular user equipment.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the cell selection control mechanism into separate information elements: cellBarred for controlling user equipment access and intraFreqReselection for controlling relay node behavior. This segmentation allows independent control of different node types without mutual interference, resolving the contradiction between network stability and relay communication.

Inventive Principle:

Principle #1Segmentation

2Productivity

If relay nodes ignore cellBarred information elements, then relay communication is maintained, but interference control becomes difficult

Engineering Contradiction:

Improverelay communication capabilityVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies differentiated control strategies: user equipment strictly follows cellBarred indications to prevent interference, while relay nodes use intraFreqReselection parameters to maintain communication. This local quality differentiation allows each node type to behave appropriately for its function while maintaining overall network stability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The intraFreqReselection information element acts as an intermediary that specifically controls relay node behavior without affecting user equipment. This intermediary mechanism allows relay nodes to operate in barred cells when appropriate while maintaining interference control through parameter-based management.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If separate information elements are transmitted for relay nodes and user equipment, then precise control is achieved, but signaling overhead increases

Engineering Contradiction:

Improvecontrol precisionVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent uses universal information elements (cellBarred and intraFreqReselection) that serve multiple functions: cellBarred controls both user equipment and provides baseline control for relay nodes, while intraFreqReselection provides additional control specifically for relay nodes. This multi-functionality achieves precise control without requiring completely separate signaling channels.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the control mechanisms by having relay nodes consider both cellBarred and intraFreqReselection parameters together, while user equipment only considers cellBarred. This merging approach allows unified signaling structure with differentiated interpretation, reducing overhead while maintaining control precision.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12615574B2Communication control method

Publication Date: 2026.04.28 KYOCERA CORP

AI summary

A communication control method is a method for selecting a candidate cell in which a relay node exists in a cellular communication system. The communication control method includes transmitting, by a node configured to manage a cell, a first information element indicating whether selection of the cell is barred, and a second information element regarding whether selection of another cell belonging to a frequency identical to a frequency of the cell is allowed when the selection of the cell is barred. The first information element is applied to both the relay node and a user equipment. The transmitting includes transmitting the second information element for the relay node as an information element different from the second information element for the user equipment.