DU Radio Bearer Modification in CU-DU Split Architecture

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Solution Overview

Problem

In wireless communication systems, particularly in 5G and LTE-A networks, there is a need to modify radio bearers established between user equipment and distributed units of base stations due to changing radio resource situations, which existing technologies do not efficiently address.

Innovation Solution

A method and apparatus for modifying radio bearers by the distributed unit (DU) of a base station, where the DU decides to modify established radio bearers based on current radio resource situations, and communicates with the central unit (CU) to accept or reject these modifications, allowing for adding, modifying, or releasing radio bearers, ensuring optimal resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the DU triggers a radio bearer modification procedure to adapt to changing radio resource situations, then the adaptability and resource utilization improve, but the signaling overhead and procedure complexity increase

Engineering Contradiction:
Improveradio bearer adaptabilityVSAvoidmodification procedure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The radio bearer modification procedure is segmented into distinct phases: DU initiates modification indication, CU processes and decides, then CU sends modification confirmation. This segmentation allows each node to perform specific functions independently, improving adaptability while managing complexity through clear procedural boundaries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The DU performs preliminary assessment of radio resource situations before triggering modification procedures. By evaluating current resource conditions in advance, the system can initiate modifications proactively rather than reactively, improving adaptability to changing conditions while reducing unnecessary signaling overhead.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If real-time radio bearer modifications are enabled based on current radio resource conditions, then resource utilization efficiency improves, but the signaling overhead and processing time increase

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidmodification signaling time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system applies partial modification actions by only modifying specific radio bearers that require changes based on current resource conditions, rather than reconfiguring all bearers. This selective approach improves resource utilization efficiency while minimizing signaling overhead and processing time.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The modification procedure incorporates feedback mechanisms where the DU monitors radio resource conditions, triggers modifications when thresholds are met, and the CU provides confirmation. This feedback-driven approach enables timely resource optimization while controlling signaling frequency to reduce time loss.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3512296B1Methods and device for modifying a radio bearer in CU-du split scenario
Publication Date: 2021.02.24 LG ELECTRONICS INC
  • EP3512296B1 patent drawingFigure 1
  • EP3512296B1 patent drawingFigure 2
  • EP3512296B1 patent drawingFigure 3

AI summary

Provided are a method of modifying a radio bearer for a user equipment by a distribution unit (DU) of a base station in a wireless communication system, and an apparatus supporting the method. The method may include: deciding to modify the radio bearer for the user equipment; transmitting information on the radio bearer to a central unit (CU) of the base station; receiving information on an accepted radio bearer from the CU of the base station; and modifying the accepted radio bearer.