Dual Connectivity RRC Reconfiguration Failure Handling

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Solution Overview

Problem

Existing wireless communication systems face challenges in handling dual connectivity when a radio resource control (RRC) reconfiguration failure occurs, as there is no clear method for user equipment (UE) to communicate with both the master base station (MBS) and secondary base station (SBS) in such scenarios.

Innovation Solution

A communication device and method that establish an RRC connection with a MBS via a first carrier frequency, receive an RRC reconfiguration message to connect to a SBS via a second carrier frequency, determine reconfiguration failures, and transmit notification messages to the MBS to indicate these failures, enabling RRC connection reestablishment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE establishes dual connectivity with both MBS and SBS, then communication reliability is improved, but system complexity increases when handling RRC reconfiguration failures

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the failure handling process into distinct scenarios: SCG failure, MCG failure, and combined failures. Each scenario has a specific failure message and handling procedure, dividing the complex dual connectivity failure management into manageable, standardized segments that reduce overall system complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces the MBS as an intermediary that relays failure notifications between the UE and the network. When the UE detects an RRC reconfiguration failure, it sends a failure message to the MBS, which then coordinates with the SBS to resolve the issue, simplifying the UE's burden in directly managing complex inter-base station communications

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the UE transmits detailed failure notification messages to the MBS, then failure detection precision is improved, but message transmission time increases

Engineering Contradiction:
Improvefailure detection precisionVSAvoidmessage transmission time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by having the UE send a failure indication message to the MBS immediately upon detecting an RRC reconfiguration failure, before attempting any recovery procedures. This immediate notification allows the network to prepare appropriate recovery actions, reducing overall resolution time while maintaining precise failure detection

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the parameter of failure message content based on the failure scenario. For SCG failures, the UE includes specific SCG configuration failure information; for MCG failures, it includes MCG-related failure details. This parameter adaptation ensures precise failure detection without unnecessarily increasing message size or transmission time

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3358907B1Device and method of handling dual connectivity
Publication Date: 2021.05.12 HTC CORP
  • EP3358907B1 patent drawingFigure 1
  • EP3358907B1 patent drawingFigure 2
  • EP3358907B1 patent drawingFigure 3

AI summary

A communication device of handling dual connectivity comprises instructions of establishing a radio resource control (RRC) connection to a master base station (MBS) via at least one first carrier frequency; receiving a first RRC reconfiguration message from the MBS via the RRC connection, wherein the first RRC reconfiguration message configures the communication device to connect to a secondary base station (SBS) via at least one second carrier frequency; determining a first reconfiguration failure according to a first configuration for communicating with the SBS in the first RRC reconfiguration message; and transmitting a RRC notification message to the MBS via the RRC connection to indicate the first reconfiguration failure, in response to the first reconfiguration failure.