Dual Connectivity Handover via Small Cell Maintenance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless access systems face challenges in maintaining seamless handover in small cell environments, particularly in dual connectivity mode, where ensuring continuous downlink data transmission during handover is crucial for user equipment (UE) connectivity.

Innovation Solution

A method and apparatus for supporting handover in a wireless access system by receiving measurement reports from UE, transmitting small cell maintenance requests, and responding with maintenance information, allowing the UE to maintain dual connectivity with both source and target cells, ensuring seamless data service through the small cell.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If handover is performed in dual connectivity mode, then mobility and connectivity are improved, but maintaining small cell connection during handover becomes complex

Engineering Contradiction:
ImproveconnectivityVSAvoidhandover procedure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The source cell sends a small cell maintenance request message to the target cell before the handover is completed. This preliminary action ensures that the target cell is prepared to maintain the small cell connection, avoiding the need for complex post-handover reconfiguration and ensuring seamless connectivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The small cell maintenance request message acts as an intermediary mechanism between the source cell and target cell. It carries necessary information about the small cell connection, enabling the target cell to understand and maintain the dual connectivity configuration without complex direct coordination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If small cell connection is maintained during handover, then data service continuity is improved, but signaling overhead increases

Engineering Contradiction:
Improvedata service continuityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The small cell maintenance request message extracts and transmits only the essential information needed to maintain the small cell connection during handover. By taking out only the necessary parameters and configuration details, the signaling overhead is minimized while still ensuring data service continuity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If dual connectivity mode is maintained, then downlink data transmission reliability is improved, but resource management complexity increases

Engineering Contradiction:
Improvedownlink data transmissionVSAvoidresource management
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The target cell autonomously processes the small cell maintenance request message and determines whether to maintain the small cell connection based on its own resource availability and configuration. This self-service approach reduces the need for complex coordination between source and target cells, simplifying resource management while maintaining downlink data transmission reliability.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2978261B1Method for performing handover in wireless access system supporting double connection mode
Publication Date: 2019.07.24 LG ELECTRONICS INC
  • EP2978261B1 patent drawingFigure 1
  • EP2978261B1 patent drawingFigure 2
  • EP2978261B1 patent drawingFigure 3~4

AI summary

The present invention relates to a wireless access system, and particularly, provides a method for performing seamless handover in a network system supporting a double connectivity mode, and apparatuses supporting the method. As an embodiment of the present invention, a method for supporting handover by a source cell in a wireless access system supporting a double connectivity mode may comprise the steps of: receiving a measurement report message from a user equipment; transmitting small cell maintenance request information to a target cell; and receiving small cell maintenance response information from the target cell. The double connectivity mode is a mode in which a terminal maintains simultaneous connection to the source cell and a small cell. The small cell maintenance request information is information for requesting maintenance of the double connectivity mode for the small cell in order to support the handover. The small cell maintenance response information is information for indicating whether the target cell can maintain the double connectivity mode for the small cell.