SMSF Subscriber Context Retrieval for 5G Message Failover

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Solution Overview

Problem

The 3GPP protocol lacks solutions for abnormal scenarios in 5G Core network elements, such as SMSF failure, leading to short message delivery failures and degraded user experience due to missing subscriber context information during network abnormalities or SMSF downtime.

Innovation Solution

Implement a communication connection method that ensures subscriber context information is retrieved from UDM when not found in the cache, and employs disaster backup SMSF network elements and cache validity period management to maintain message delivery during failures and abnormalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the SMSF relies on cache storage for subscriber context information, then message delivery speed is improved, but reliability deteriorates when the cache is invalid or the SMSF fails

Engineering Contradiction:
Improvemessage delivery speedVSAvoidmessage delivery reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The system performs preliminary actions by pre-fetching and caching subscriber context information from the UDM before it is needed for message delivery. The cache stores subscriber context information with validity periods, and the system proactively refreshes cache entries before they expire, ensuring that valid cached data is available when messages need to be delivered, thus maintaining both speed and reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism between the SMSF cache and the UDM database. When the SMSF fails or the cache is invalid, the system uses the UDM as an intermediary to retrieve subscriber context information and transfer it to a backup SMSF or restore it to the original SMSF, ensuring continuous message delivery capability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the system implements disaster backup SMSF network elements, then reliability is improved during failures, but device complexity increases

Engineering Contradiction:
Improvesystem reliability during failuresVSAvoidnetwork element complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system creates a copy (backup) of the SMSF network element that can take over when the primary SMSF fails. The backup SMSF maintains necessary subscriber context information and can process messages, ensuring continuity of service. This copying approach provides fault tolerance while keeping the backup element structurally similar to the primary element, limiting the increase in complexity

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system changes the operational parameters of the SMSF by implementing dynamic failover mechanisms. When failure is detected, the system changes the active status parameter from the primary SMSF to the backup SMSF, and adjusts the cache validity period parameters to ensure data consistency. These parameter changes enable reliability improvement without requiring fundamentally different system architecture

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4068813B1Communication method, system and storage medium
Publication Date: 2025.11.26 ZTE CORP
  • EP4068813B1 patent drawingFigure 1~2
  • EP4068813B1 patent drawingFigure 3~4
  • EP4068813B1 patent drawingFigure 5

AI summary

Provided by the present application are a communication connection method and device and a storage medium. The communication connection method comprises: parsing and obtaining a user permanent identification number of a calling user according to a user call message; when user context information corresponding to the user permanent identification number is not found in a preset buffer, carrying the user permanent identification number to send an information acquisition request to a unified data management (UDM) device; receiving the corresponding user context information fed back by the UDM device, the user context information comprising: information about the calling user, information of an access and mobility management function AMF device where the calling user is located and contract data information; and according to the fed back user context information, continuing the corresponding call process.