UL PDCP Duplication Activation in CU/DU Split Networks

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Solution Overview

Problem

Current technologies lack a complete solution for activating uplink (UL) PDCP duplication during bearer configuration in both CA-based and DC-based scenarios, especially in the CU/DU split and multi-RAT double connection scenarios.

Innovation Solution

A method where a second node receives a notification message from a first node to configure PDCP duplication for a bearer, allowing the second node to activate or deactivate UL PDCP duplication, using MAC CE signaling for state changes and providing priority services based on activation states, specifically addressing the CU/DU split and MR-DC scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PDCP duplication is configured for a bearer in CU/DU split scenario, then data transmission reliability is improved, but the mechanism for activating UL duplication is incomplete and unclear

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidUL duplication activation mechanism
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by pre-configuring PDCP duplication parameters and activation conditions in the RRC connection setup. The CU prepares duplication configurations including RLC entity associations and activation criteria before actual data transmission, enabling rapid UL duplication activation when conditions are met without requiring complex runtime negotiation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces the RRC layer as an intermediary between the CU's PDCP layer and the DU's RLC layer for managing duplication activation. The RRC configuration messages carry duplication activation commands from the CU to the DU, providing a standardized interface that resolves the activation mechanism gap in CU/DU split scenarios.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If PDCP duplication is configured in MR-DC scenario, then transmission reliability is improved, but the activation control mechanism for UL duplication is incomplete

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidactivation control mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the duplication control function between master node and secondary node in MR-DC scenario. The master node's RRC layer manages the overall duplication configuration and activation decisions, while the secondary node executes the activation based on received commands, dividing the complex control mechanism into manageable segments with clear responsibilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic activation control where UL duplication can be activated or deactivated based on real-time transmission conditions. The RRC configuration allows the system to dynamically switch between single-path and dual-path transmission modes, adapting to changing channel conditions and traffic requirements in MR-DC scenarios.

Inventive Principle:
Principle #15Dynamics

3Reliability

If UL PDCP duplication is activated, then data transmission reliability is improved, but signaling overhead and system complexity increase

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies partial action by activating PDCP duplication only for specific uplink bearers that require enhanced reliability, rather than enabling it system-wide. The RRC configuration selectively applies duplication activation to particular data radio bearers based on their QoS requirements, reducing unnecessary signaling overhead for bearers that don't need duplication.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent uses parameter changes in RRC configuration messages to control duplication activation. By modifying specific RRC parameters related to PDCP duplication status, the system can activate or deactivate UL duplication without requiring complete reconfiguration messages, thereby minimizing signaling overhead while maintaining reliability improvements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3751955B1Methods for activating packet data convergence protocol (PDCP) repetition mechanism and node devices
Publication Date: 2024.07.24 DATANG MOBILE COMM EQUIP CO LTD
  • EP3751955B1 patent drawingFigure 1
  • EP3751955B1 patent drawingFigure 2~3
  • EP3751955B1 patent drawingFigure 4~6

AI summary

The present disclosure provides a method for activating a packet data convergence protocol (PDCP) duplication and a node device. The method includes: receiving, by a second node, a notification message transmitted by a first node when the first node configures a PDCP duplication for a bearer; after the second node receives the notification message, changing or determining, by the second node, an activation or deactivation state of uplink (UL) PDCP duplication of the bearer.