PDCP Entity Release in Dual Connectivity Handover

Solution Overview

Problem

In dual connectivity networks, the excessive time required for inter-base-station handover due to the need for a modification procedure between master and secondary base stations leads to handover performance deterioration, causing service interruptions and user experience issues due to configuration inconsistencies between the terminal and the target access network.

Innovation Solution

A communication method where the source access network device sends identifiers of data radio bearers to the target access network device, receiving configuration information to indicate the terminal to release or add PDCP entities, ensuring consistency and avoiding service interruptions by bypassing the need for incremental configuration updates during handover.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a modification procedure is performed before handover to obtain latest PDCP configuration from source SN, then configuration consistency is improved, but handover time increases excessively

Engineering Contradiction:

Improveconfiguration consistencyVSAvoidhandover time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The source MN performs preliminary action by obtaining the latest PDCP configuration from the source SN before initiating handover. This preliminary configuration acquisition ensures that the target MN has accurate configuration information, preventing configuration inconsistency during handover without requiring the modification procedure to be triggered excessively early.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The source SN acts as an intermediary by providing the latest PDCP configuration to the source MN. This intermediary mechanism allows the target MN to obtain accurate configuration information indirectly through the source MN, eliminating the need for direct modification procedures between target MN and source SN while ensuring configuration consistency.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If modification procedure is triggered before handover, then target base station can generate incremental configuration, but handover performance deteriorates due to excessively long handover process

Engineering Contradiction:

Improveconfiguration generation capabilityVSAvoidhandover speed

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The source MN performs preliminary action by obtaining the latest PDCP configuration from the source SN before initiating handover. This preliminary configuration acquisition ensures that the target MN has accurate configuration information, preventing configuration inconsistency during handover without requiring the modification procedure to be triggered excessively early.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The target MN copies the PDCP configuration obtained from the source MN (which was obtained from the source SN) to generate the incremental configuration for the handover. This copying mechanism allows the target MN to generate necessary configuration without requiring real-time modification procedures during handover, maintaining handover speed while ensuring configuration accuracy.

Inventive Principle:

Principle #26Copying

3Loss of time

If source MN does not obtain PDCP configuration from source SN, then handover time is reduced, but configuration inconsistency causes service interruption

Engineering Contradiction:

Improvehandover timeVSAvoidconfiguration consistency

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The source MN performs preliminary action by obtaining the latest PDCP configuration from the source SN before initiating handover. This preliminary configuration acquisition ensures that the target MN has accurate configuration information, preventing configuration inconsistency during handover without requiring the modification procedure to be triggered excessively early.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The source MN uses feedback from the source SN's PDCP configuration to ensure that the target MN generates correct incremental configuration. This feedback mechanism allows the source MN to verify configuration accuracy before handover, preventing service interruption while maintaining efficient handover timing.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12063562B2Communication method and apparatus for releasing a packet data convergence protocol entity of a data radio bearer

Publication Date: 2024.08.13 HUAWEI TECH CO LTD

AI summary

Embodiments of this application provide a communication system and apparatus, and relate to the field of communication technologies. In the communication system, a source access network device is configured to send at least one identifier of at least one first data radio bearer (DRB) to a target access network device, where the source access network device does not obtain a packet data convergence protocol (PDCP) configuration of the first DRB, and a target access network device is configured to receive the at least one identifier of the at least one first DRB from the source access network device, and obtain configuration information, where the configuration information comprises first indication information, and the first indication information indicates the terminal to release at least one PDCP entity of the at least one first DRB; and send the configuration information to the source access network device.