SCG Failure Reporting for Accurate Rel-15 and Rel-16 Recovery

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In multi-RAT dual connectivity scenarios, the UE's SCG failure information procedure in 5G/NR networks can lead to incorrect interpretations by the E-UTRAN, resulting in incorrect operations and connectivity issues due to erroneous interpretation of the failureType field in the SCGFailureInformation-NR message.

Innovation Solution

The proposed solution involves enhancing the SCG failure information procedure by distinguishing between failure causes associated with Rel-15 and Rel-16 communication functionalities, using specific indications (failureType-r15, failureType-r16, and failureTypeOther-r16) to accurately convey the failure cause, thereby preventing ASN.1 syntax errors and ensuring correct SCG recovery procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the UE uses a unified failureType field to report SCG failures in both Rel-15 and Rel-16, then the message structure remains simple and backward compatible, but the E-UTRAN may incorrectly interpret Rel-16 specific failure causes as Rel-15 failure types leading to operation errors

Engineering Contradiction:

Improvebackward compatibilityVSAvoidfailure cause interpretation accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The failureType field is segmented into multiple specialized fields: failureType-r15 for Rel-15 failure causes and failureType-r16 for Rel-16 failure causes. This segmentation allows the UE to report failures with version-specific accuracy while the E-UTRAN can correctly interpret the failure cause based on which field is present in the message.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the failure reporting mechanism have different qualities: the failureType-r15 field contains Rel-15 specific failure causes with Rel-15 interpretation rules, while the failureType-r16 field contains Rel-16 specific failure causes with Rel-16 interpretation rules. This local quality ensures each failure cause is interpreted with the correct version-specific semantics.

Inventive Principle:

Principle #3Local quality

2Reliability

If the UE includes multiple failureType fields (failureType-r15 and failureType-r16) to distinguish failure causes, then the E-UTRAN can correctly interpret the failure cause, but the message structure becomes more complex

Engineering Contradiction:

Improvefailure cause interpretation accuracyVSAvoidmessage structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The Rel-16 specific failure cause information is extracted into a separate failureType-r16 field, distinct from the traditional failureType-r15 field. This extraction allows the E-UTRAN to identify and process only the relevant field based on the failure cause type, avoiding the need to parse and interpret both fields in all cases, thus managing complexity efficiently.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If the E-UTRAN implements SCG recovery procedures for all possible failure types, then the system can handle diverse failure scenarios, but the recovery procedure complexity and processing time increase

Engineering Contradiction:

Improvefailure scenario coverageVSAvoidrecovery procedure time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The UE performs preliminary classification of the failure cause into Rel-15 or Rel-16 categories before reporting, by setting the appropriate failureType field. This preliminary action allows the E-UTRAN to immediately identify the correct recovery procedure based on the failure type without needing to analyze detailed failure characteristics, thus reducing recovery time while maintaining comprehensive coverage.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12610293B2Communicating failure information for a secondary cell group (SCG)

Publication Date: 2026.04.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Embodiments include methods for a user equipment (UE) configured to communicate with a wireless network via a master cell group (MCG) and a secondary cell group (SCG). Such methods include detecting a failure in the SCG and selecting a failure cause. The failure cause is selected from the following: a first set of causes associated with an earlier version of communication functionality, and a second set of causes associated with a later version of communication functionality. Such methods include sending a failure information message to a network node that provides the MCG, wherein the failure information message indicates whether the failure cause is one of the first set or one of the second set. Other embodiments include complementary methods for a network node that provides the MCG, as well as UEs and network nodes configured to perform such methods.