Multi-SIM Error Cause Reporting for Idle-SIM RRC Disconnections

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Solution Overview

Problem

Terminals supporting multiple SIM cards experience cumulative long intervals and network errors due to operations performed by idle SIM cards, leading to misinterpretation by base stations as errors, which current technologies fail to address effectively.

Innovation Solution

The terminal records and reports a target error cause for disconnecting an RRC connection due to operations by an idle SIM card, allowing the base station to ignore this cause and focus on other errors, reducing network error statistics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the terminal performs operations for the second SIM card (reading paging message, reading system message, measurement, or tracking area update), then the second SIM card can access the network normally, but the RRC connection with the first base station is disconnected causing cumulative long intervals and network errors

Engineering Contradiction:
Improvemulti-SIM card operation capabilityVSAvoidRRC connection stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the error cause into two categories: normal errors (caused by SIM card operations) and abnormal errors (caused by actual connection issues). By dividing the error reporting mechanism, the system can distinguish between intentional disconnections for SIM operations and genuine connection failures, allowing the base station to apply different handling strategies for each type.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism (error cause indication field and specific error cause values) between the terminal and base station to convey the true reason for RRC connection disconnection. This intermediary allows the terminal to explain that the disconnection was intentional for SIM card operations rather than an actual connection failure, enabling the base station to avoid unnecessary recovery actions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the base station performs recovery mechanisms for all reported errors, then connection reliability is improved, but unnecessary recovery actions increase network error statistics and reduce network efficiency

Engineering Contradiction:
Improveconnection recovery reliabilityVSAvoidnetwork error handling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements a feedback mechanism where the terminal provides detailed error cause information to the base station through the RRC connection reestablishment process. The base station uses this feedback to determine whether recovery actions are necessary, avoiding unnecessary interventions for normal SIM card operations while maintaining recovery for actual connection failures.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the parameter of error cause reporting by introducing specific error cause values (first error cause indicating normal error, second error cause indicating abnormal error) in the RRC connection reestablishment message. This parameter change enables the base station to differentiate between error types and adjust its recovery behavior accordingly, improving network efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3962226B1Error cause reporting method and device
Publication Date: 2025.08.27 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3962226B1 patent drawingFigure 1~2
  • EP3962226B1 patent drawingFigure 3
  • EP3962226B1 patent drawingFigure 4

AI summary

Methods and apparatuses for reporting an error cause are provided. Reporting the error cause includes: after establishing a radio resource control (RRC) connection with a first base station, detecting whether the RRC connection is disconnected due to execution of a target operation; where the first base station is a base station accessed by a first SIM card of the terminal, and the target operation is an operation executed by a second SIM card in an idle state in the terminal; if the RRC connection is disconnected due to execution of the target operation, recording that a target error cause of disconnecting the RRC connection is resulted from the target operation. In the present disclosure, the terminal may record the target error cause of disconnecting the RRC connection with the first base station due to the target operation to subsequently enable the first base station not to perform recovery for the target error cause any longer, thus reducing network errors statistics.