gNB-DU System Information Encoding Segmentation

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Solution Overview

Problem

In a gNB decomposed into a gNB-CU and a gNB-DU, there is a need for efficient mechanisms to provide and broadcast System Information (SI), particularly to reduce wasteful signaling between the gNB-CU and gNB-DU, and to ensure accurate and reliable SI delivery via dedicated unicast signaling.

Innovation Solution

The gNB-DU indicates its capability to generate information related to Other-System Information (OSI) to the gNB-CU, allowing the gNB-CU to opt out of continuous updates and enabling the gNB-DU to autonomously generate and broadcast certain SIBs. Additionally, the gNB-CU can request information from the gNB-DU for dedicated unicast signaling, reducing unnecessary decoding and re-encoding at the gNB-DU.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gNB-CU continuously provides System Information updates to the gNB-DU, then the gNB-CU maintains control over System Information encoding, but excessive signaling overhead is generated and time is wasted

Engineering Contradiction:
ImproveSystem Information accuracyVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the System Information encoding function by allowing the gNB-DU to autonomously encode specific SIBs (SIB9 and others) without requiring continuous input from the gNB-CU. This segmentation enables the gNB-DU to independently generate and broadcast these SIBs, eliminating the need for continuous signaling updates from the gNB-CU while maintaining system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gNB-DU is enabled to self-generate and self-encode System Information (specifically SIB9 and other designated SIBs) without requiring continuous assistance from the gNB-CU. This self-service capability allows the gNB-DU to autonomously perform the encoding function, significantly reducing the signaling overhead that would otherwise be required for continuous updates.

Inventive Principle:
Principle #25Self-service

2Reliability

If the gNB-CU encodes all System Information, then centralized control is maintained, but accurate time-reference information cannot be reliably provided to UEs

Engineering Contradiction:
Improvetime-reference accuracyVSAvoidsynchronization requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the encoding responsibility for different System Information types. The gNB-DU is specifically assigned the task of encoding SIB9 and other SIBs that contain time-reference information. This segmentation allows the gNB-DU, which has direct access to accurate time-reference data, to encode this information locally, ensuring accuracy without requiring complex synchronization between the gNB-CU and gNB-DU.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gNB-DU acts as an intermediary that receives time-reference information from the gNB-CU and independently encodes it into SIB9 and other relevant SIBs. This intermediary role allows the gNB-DU to leverage the time-reference data while performing the actual encoding operation locally, ensuring accuracy without imposing strict synchronization requirements on the entire system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If the gNB-DU re-encodes SIB9, then some signaling reduction is achieved, but the gNB-CU still provides inaccurate information in dedicated signaling cases

Engineering Contradiction:
Improvesignaling reductionVSAvoidinformation accuracy
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent segments the System Information delivery into two distinct paths: broadcast delivery (where the gNB-DU autonomously encodes SIB9 and other SIBs) and dedicated unicast delivery (where the gNB-CU provides accurate time-reference information). This segmentation allows each path to be optimized independently - the broadcast path benefits from reduced signaling overhead while the unicast path maintains high information accuracy through direct gNB-CU provisioning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different quality characteristics to different delivery methods. For broadcast delivery, the focus is on reducing signaling overhead by allowing the gNB-DU to autonomously encode SIBs. For dedicated unicast delivery, the focus is on ensuring high information accuracy by having the gNB-CU directly provide time-reference information. This local quality differentiation allows each delivery mechanism to optimize for its specific requirements.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3815428B1System information delivery enhancements
Publication Date: 2025.05.07 NOKIA SOLUTIONS & NETWORKS OY
  • EP3815428B1 patent drawingFigure 1
  • EP3815428B1 patent drawingFigure 2
  • EP3815428B1 patent drawingFigure 3

AI summary

In a first method, a gNB-DU indicates, to a second node, a capability information element for generating information related to Other-System Information (OSI); receives an acknowledge indication from the second node; and generates system information broadcast information to at least one user equipment. In a second method, a gNB-CU receives, from a first node, a capability information element for generating information related to Other-System Information (OSI); and transmits an acknowledge indication to the first node.