RAN Handover Control Across Different RATs for Stable 5G Coverage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Transitioning to 5G wireless systems with Dual Connectivity (DC) is challenging under a multi-vendor environment, making it difficult to stabilize initial coverage during deployment.

Innovation Solution

A network node that includes a communication unit, reception unit, and control unit to manage handovers to RAN nodes with different radio access technologies, enabling stabilization of coverage without relying on DC.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Dual Connectivity (DC) is adopted to stabilize initial coverage during wireless system deployment, then coverage stability is improved, but implementation difficulty increases under multi-vendor environments

Engineering Contradiction:
Improvecoverage stabilityVSAvoidimplementation difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the handover control function from the complex DC architecture and implements it as a standalone mechanism in the source RAN node. The source RAN node directly determines handover timing and controls the handover process to the target RAN node, removing the need for coordinated DC management between multiple vendors while maintaining coverage stability during transition.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the handover control process into distinct phases: measurement phase where the terminal collects signal quality data, determination phase where the source RAN node decides handover timing based on measurements, and execution phase where the handover is performed. This segmentation allows each phase to be optimized independently and simplifies multi-vendor integration.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If handover control is centralized in the source RAN node to simplify multi-vendor deployment, then ease of implementation is improved, but handover precision may deteriorate

Engineering Contradiction:
Improveease of implementationVSAvoidhandover precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where the terminal continuously measures signal quality of both source and target RAN nodes and reports these measurements to the source RAN node. The source RAN node uses this real-time feedback to accurately determine the optimal handover timing, ensuring precise handover execution despite the centralized control architecture.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary actions by having the terminal proactively measure and report signal quality parameters before handover is needed. The source RAN node uses these pre-collected measurements to predict the optimal handover moment, allowing precise handover timing to be determined in advance rather than reactively during the handover event.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4651563A1Network node and communication method
Publication Date: 2025.11.19 NTT DOCOMO INC
  • EP4651563A1 patent drawingFigure 1
  • EP4651563A1 patent drawingFigure 2
  • EP4651563A1 patent drawingFigure 3

AI summary

A network node includes: a communication unit configured to perform communications with a terminal, serving as one of master nodes together with another RAN (Radio Access Network) node; a reception unit configured to receive information related to the another RAN node from an AMF (Access and Mobility Management Function); and a control unit configured to control a handover of the terminal. The control unit determines, as a destination of the handover of the terminal, a RAN node that uses a RAT (Radio access technology) that is different from that of the another RAN node, based on the information related to the another RAN node.