SDAP Entity Management During RRC Reestablishment

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Solution Overview

Problem

The introduction of the Service Data Adaptation Protocol (SDAP) layer in 5G wireless communication systems poses challenges in managing and configuring SDAP entities within the Radio Resource Control (RRC) connection management procedure, particularly in scenarios involving dual connectivity and RRC connection reestablishment.

Innovation Solution

A wireless protocol layer entity processing method that suspends or stores SDAP operations and configurations during RRC connection reestablishment, allowing for efficient handling of SDAP entities across multiple cell groups, thereby reducing packet loss and resource overheads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If SDAP entities and configurations are continuously maintained during RRC connection reestablishment, then QoS flow management capability is preserved, but device complexity and resource overhead increase

Engineering Contradiction:
ImproveQoS flow management capabilityVSAvoidSDAP entity maintenance complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by suspending SDAP operations and storing configurations before RRC connection reestablishment occurs. This allows the system to prepare in advance for the connection change, preserving QoS flow management capability while avoiding the complexity of continuous maintenance during the reestablishment process. The SDAP entity is suspended rather than actively maintained, yet configurations are preserved for later restoration.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If SDAP operations are suspended during RRC connection reestablishment, then device complexity and resource overhead are reduced, but packet loss may increase

Engineering Contradiction:
ImproveSDAP entity maintenance complexityVSAvoidpacket loss rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements beforehand cushioning by storing SDAP configurations before suspending operations during RRC connection reestablishment. This preparatory measure ensures that when the connection is reestablished, the SDAP entity can be quickly restored with its configuration intact, minimizing packet loss while still reducing complexity during the suspension period. The stored configuration acts as a cushion against potential data loss.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses copying by creating and storing a copy of the SDAP configuration before suspending the SDAP entity during RRC connection reestablishment. This copied configuration can be restored afterward, ensuring that the original data is preserved even though the active entity is suspended. This approach minimizes packet loss while maintaining low complexity during the suspension phase.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If SDAP configuration is stored in each cell group, then adaptability to dual connectivity scenarios is improved, but memory requirements increase

Engineering Contradiction:
Improvedual connectivity supportVSAvoidconfiguration storage memory
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies segmentation by dividing the SDAP configuration management into separate cell group configurations. Each cell group has its own SDAP configuration that can be independently stored and restored. This segmentation enables adaptability to dual connectivity scenarios where different cell groups may have different QoS requirements, while the overall memory usage is optimized through this modular approach rather than duplicating entire SDAP entities across all cell groups.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3641483B1Wireless protocol layer entity processing method and corresponding user equipment
Publication Date: 2023.08.02 FG INNOVATION CO LTD
  • EP3641483B1 patent drawingFigure 1
  • EP3641483B1 patent drawingFigure 2

AI summary

The present disclosure provides a method executed at UE, including: determining initiation of a radio resource control (RRC) connection reestablishment procedure or leaving RRC connected state; and performing the following operations on each of at least one cell group: suspending a service data adaptation protocol (SDAP) operation and/or storing an SDAP configuration in a corresponding cell group configuration; or releasing an SDAP entity used to execute the SDAP operation and/or the SDAP configuration in the corresponding cell group configuration. The present disclosure further provides corresponding UE.