LTE MeNB Handover via SeNB Context Pre-configuration

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Solution Overview

Problem

In LTE networks, frequent handovers between master evolved NodeB (MeNB) and secondary evolved NodeB (SeNB) lead to data traffic interruptions and dropped calls due to the inability to efficiently migrate UE context and configuration information, especially when the MeNB changes, resulting in increased signaling overhead and potential system congestion.

Innovation Solution

A handover method where the source MeNB initiates a handover command to the UE, sending bearer information and context configuration details to the destination MeNB, allowing the SeNB to maintain connection and switch control plane management, ensuring seamless data offloading without interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If frequent inter-cell handovers are performed when the number of LPN cells is large, then user mobility is supported, but data service interruption and call dropping increase

Engineering Contradiction:

Improveuser mobility supportVSAvoiddata service continuity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The source MeNB performs preliminary actions by determining the target SeNB before the handover is executed, and pre-configures the necessary bearer information and context. This allows the target SeNB to be ready to immediately take over data transmission, preventing service interruption during the actual handover execution.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention introduces the S-GW as an intermediary anchor point that maintains the data transmission path during handover. The S-GW receives data from the source MeNB and forwards it to the target SeNB, ensuring continuous data flow even when the MeNB changes, thus decoupling the control plane handover from the user plane data path.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If frequent handovers occur between MeNB and SeNB, then user mobility is maintained, but signaling overhead increases and system congestion occurs

Engineering Contradiction:

Improveuser mobility maintenanceVSAvoidsignaling overhead

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The invention extracts the data transmission function from the MeNB handover process by introducing the S-GW as a separate anchor point. This allows the control plane handover signaling to be minimized while the user plane data path remains stable, separating the signaling overhead from the data transmission continuity requirement.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The source MeNB performs preliminary determination of the target SeNB and pre-configures bearer information before handover execution. This reduces the need for extensive signaling during the actual handover process, as the target SeNB is already prepared with the necessary context and configuration.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If MeNB changes during dual connectivity, then network load balancing is improved, but UE context and configuration information migration fails

Engineering Contradiction:

Improvenetwork load balancingVSAvoidUE context migration

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The S-GW acts as an intermediary that maintains the user plane data path during MeNB handover. It receives data from the source MeNB and forwards to the target SeNB, ensuring that data transmission continues uninterrupted even when the MeNB changes and UE context is being migrated between base stations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The source MeNB determines the target SeNB in advance and pre-configures the bearer information and UE context before the handover is executed. This ensures that when the MeNB changes, the target SeNB is already prepared with all necessary context information, preventing any loss of UE configuration during the transition.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9906994B2Handover method, master base station and slave base station

Publication Date: 2018.02.27 ZTE CORP

AI summary

Disclosed are a handover method, a master evolved NodeB (MeNB) and a secondary evolved NodeB (SeNB), wherein, the method is applied to perform a handover on a MeNB for a user equipment (UE) in a multi-connection scenario in which the UE has connections with both a master evolved NodeB (MeNB) and a secondary evolved NodeB (SeNB), including: a source MeNB initiating a handover, and sending a handover command to the UE after receiving a corresponding response, instructing the UE to perform the handover on the MeNB via the handover command, and remaining a connection with the SeNB; after the UE successfully accesses a destination MeNB, the source MeNB or the destination MeNB sending a handover instruction message to the SeNB connected with the UE, the SeNB connected with the UE establishing an association with the destination MeNB according to the handover instruction message.