CU-DU Configuration Mismatch Resolution via Feedback

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Solution Overview

Problem

In the New Radio Access Technology system, an understanding mismatch occurs between the Central Unit (CU) and Distributed Unit (DU) when the CU cannot comprehend the configured configuration received from another node, while the DU can understand it, leading to failed procedures such as SN change and handover, as there is no specified method to resolve this mismatch.

Innovation Solution

A communication device is provided that notifies another device of the need for full configuration when it cannot understand the received configuration, with methods including explicit or implicit messages indicating the requirement for full configuration, ensuring both CU and DU generate full configurations to resolve the mismatch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If CU and DU use different functional separations with different layer functions, then device complexity is reduced and flexibility is improved, but understanding mismatch occurs between CU and DU when receiving configured configuration

Engineering Contradiction:
Improvefunctional separation complexityVSAvoidconfiguration understanding consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The DU feeds back to the CU whether it can understand the configured configuration received from another gNB. This feedback mechanism allows the CU to make informed decisions about whether to generate full configuration or rely on the DU's existing configuration understanding, thereby resolving the understanding mismatch while maintaining functional separation benefits

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The CU acts as an intermediary between the external configuration source and the DU. It receives the configured configuration, assesses its own understanding, queries the DU's understanding capability, and decides whether to generate full configuration or use delta configuration, thus mediating the configuration distribution process

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If full configuration is executed to resolve understanding mismatch, then configuration consistency is improved, but signaling overhead and processing time increase

Engineering Contradiction:
Improveconfiguration understanding consistencyVSAvoidconfiguration processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Instead of always executing full configuration, the system performs partial configuration (delta configuration) when the DU can understand the received configured configuration. Full configuration is only executed when necessary (when CU cannot understand), thus reducing unnecessary signaling overhead and processing time while maintaining configuration consistency

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If CU generates full configuration when it cannot understand received configuration, then configuration reliability is improved, but device complexity and processing load increase

Engineering Contradiction:
Improveconfiguration understanding consistencyVSAvoidconfiguration management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The DU performs self-assessment of its configuration understanding capability and provides feedback to the CU. This self-service approach reduces the CU's processing burden and complexity, as the DU independently evaluates its own ability to handle the configured configuration without requiring extensive CU intervention

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3813433B1Communication device and communication method
Publication Date: 2024.05.15 NTT DOCOMO INC
  • EP3813433B1 patent drawingFigure 1
  • EP3813433B1 patent drawingFigure 2
  • EP3813433B1 patent drawingFigure 3A

AI summary

A communication unit is provided that notifies another communication device that full configuration is required to be generated when a received configured configuration cannot be understood or when a message requesting execution of full configuration is received.