Macro-Cell Handover with Pre-Handover Small-Cell Release

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional handover methods in dual connectivity scenarios, where a user equipment is connected to both a macro cell and a small cell, are inadequate and do not account for the specific connections between these cells, leading to inefficiencies in handover processes.

Innovation Solution

A communication system that includes pre-handover and post-handover processes for user equipment connected to both macro and small cells, involving disconnection from the small cell before switching macro cells and reestablishing connection with the small cell after handover, with notification to the small cell of the macro cell change during handover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional handover methods are used in dual connectivity scenarios, then the handover process is simple, but handover efficiency deteriorates due to inadequate handling of macro cell and small cell connections

Engineering Contradiction:

Improvehandover efficiencyVSAvoidhandover process complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The handover process is segmented into three distinct phases: pre-handover (disconnecting from small cell), handover (switching macro cell), and post-handover (reestablishing small cell connection). This segmentation allows each phase to be optimized independently, improving overall handover efficiency while maintaining manageable complexity through structured process division.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The small cell connection is disconnected before the macro cell handover occurs (pre-handover process). This preliminary action prevents potential conflicts between small cell and target macro cell connections, ensuring smoother handover execution and reducing handover failures, thereby improving handover efficiency without significantly increasing operational complexity.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If dual connectivity is maintained during handover, then connection continuity is improved, but handover reliability deteriorates due to potential connection conflicts

Engineering Contradiction:

Improvehandover reliabilityVSAvoidconnection flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The small cell connection is proactively disconnected before the macro cell handover to eliminate potential connection conflicts. This preliminary action ensures that the user equipment establishes a clean connection state with the target macro cell, significantly improving handover reliability by preventing duplicate or conflicting connection scenarios.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of maintaining dual connectivity during handover (connecting to both source and target macro cells simultaneously), the invention inverts the approach by temporarily reducing connectivity to a single small cell connection during the handover transition. This inversion resolves connection conflicts and improves reliability, with dual connectivity restored after successful handover.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If small cell connection is maintained during macro cell handover, then traffic handling is improved, but system stability deteriorates due to connection conflicts

Engineering Contradiction:

Improvetraffic handling capabilityVSAvoidconnection state stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The traffic handling process is segmented into phases: pre-handover traffic is handled through the small cell connection, during handover traffic is managed through the small cell with macro cell transition, and post-handover traffic is handled through both target macro cell and small cell. This segmentation ensures stable connection states in each phase while maintaining overall traffic handling capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The small cell connection is maintained as a stable anchor during the handover process, providing continuous traffic handling capability. By keeping the small cell connection active (or rapidly reestablishing it), the system ensures uninterrupted traffic flow while the macro cell transitions, maintaining both productivity and stability.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250330886A1Mobile communication system, master base station, secondary base station and user equipment

Publication Date: 2025.10.23 MITSUBISHI ELECTRIC CORP

AI summary

When being connected to a macro cell (S-MeNB) and a small cell (SeNB), a user equipment device performs a pre-handover process of disconnecting the connection with the SeNB before a handover process of switching a macro cell connected with the UE from the macro cell (S-MeNB) that is a moving source to a macro cell (T-MeNB) that is a moving destination along with moving of the UE, and after the handover process, performs a post-handover process of reestablishing the connection with the SeNB.