Terminal Device RRC Reconfiguration for DRB Release

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Solution Overview

Problem

The communication between base station apparatuses and terminal apparatuses in E-UTRA-NR Dual Connectivity and Stand Alone NR systems is inefficient due to different communication protocol formats and functions used by E-UTRA and NR core networks.

Innovation Solution

A terminal apparatus and base station apparatus are designed to process and transmit Radio Resource Control (RRC) reconfiguration messages that include Data Radio Bearer (DRB) identities, allowing the release of Packet Data Convergence Protocol (PDCP) entities and indicating information to the Service Data Adaptation Protocol (SDAP) layer for efficient protocol processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If E-UTRA and NR core networks use different communication protocol formats and functions, then each network can be optimized for its specific technology, but communication efficiency between base station apparatus and terminal apparatus deteriorates

Engineering Contradiction:
Improveprotocol optimization for specific RATVSAvoidcommunication efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies universality by enabling the terminal apparatus to handle both E-UTRA and NR protocol formats through a unified processing mechanism. The terminal can process RRC messages from both E-UTRA base stations and NR base stations using common internal structures, allowing it to operate across multiple radio access technologies without requiring separate dedicated processing paths for each RAT.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces an intermediary mapping mechanism that translates between different protocol formats. The terminal apparatus uses internal mapping tables and correspondence relationships to convert E-UTRA protocol elements to NR protocol elements and vice versa, acting as a mediator that enables efficient communication despite protocol differences between the two core networks.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the terminal apparatus processes DRB identity releases and PDCP entity releases separately for different RATs, then protocol-specific handling is maintained, but processing complexity increases

Engineering Contradiction:
Improveprotocol-specific handling accuracyVSAvoidprotocol processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the processing of DRB identity releases and PDCP entity releases into a unified procedure. When the terminal receives a DRB release indication, it automatically triggers the corresponding PDCP entity release through a combined processing flow, eliminating the need for separate independent handling of these related operations for each RAT.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements preliminary action by pre-establishing correspondence relationships between DRB identities and PDCP entities in mapping tables. Before actual release operations occur, the terminal maintains ready-made associations that enable immediate and accurate matching when releases are commanded, reducing processing complexity during dynamic operations.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If separate SDAP layer configurations are maintained for E-UTRA and NR, then protocol-specific requirements are met, but overall system complexity increases

Engineering Contradiction:
Improveprotocol complianceVSAvoidlayer configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality to the SDAP layer by implementing a single SDAP configuration that can serve both E-UTRA and NR protocols. The SDAP entity is configured to handle QoS flow to DRB mapping for both RATs through unified parameters, eliminating the need for completely separate SDAP configurations while maintaining protocol-specific compliance through flexible parameter interpretation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3793325B1Terminal device, base station device, method, and integrated circuit
Publication Date: 2024.01.31 SHARP KK
  • EP3793325B1 patent drawingFigure 1
  • EP3793325B1 patent drawingFigure 2(A)~2(B)
  • EP3793325B1 patent drawingFigure 3(A)~3(B)

AI summary

Provided is a terminal apparatus for communicating with a base station, the terminal apparatus including: a receiver configured to receive, from the base station apparatus, a Radio Resource Control layer (RRC) reconfiguration message including a list of a Data Radio Bearer (DRB) identity corresponding to a DRB to be released; and a processing unit configured to, in a case that a first DRB identity corresponding to the DRB configured for the terminal apparatus is included in the list, release a Packet Data Convergence Protocol Layer (PDCP) entity associated with the first DRB identity and indicate to a Service Data Adaptation Protocol (SDAP) layer information of the DRB corresponding to the first DRB identity.