5G NRF Token Error Handling for Service Continuity

Solution Overview

Problem

In 5G networks, there is no mechanism to synchronize the retirement of allowed authorization attributes with the expiry of access tokens across Network Function Repository Function (NRF), producer NF, and consumer NF, leading to user equipment call failures when consumer NFs attempt to access services from producer NFs with retired attributes despite valid access tokens.

Innovation Solution

Implement a method where the NRF receives an update message from the producer NF indicating retiring authorization attributes, stores them, and sends an access token error to the consumer NF before token expiry, allowing migration to a new producer NF, ensuring seamless service continuity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the producer NF retires authorization attributes to enable maintenance operations, then the network can perform maintenance and updates, but the consumer NF cannot access services from the producer NF anymore even with valid access tokens

Engineering Contradiction:

Improvemaintenance capabilityVSAvoidservice accessibility

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The NRF receives advance notification from the producer NF about upcoming attribute retirement before it actually occurs. This preliminary action allows the consumer NF to proactively renew access tokens before the retirement time, ensuring continuous service accessibility during maintenance operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where the producer NF notifies the NRF of upcoming attribute retirement, which then communicates this information to the consumer NF. This feedback loop enables coordinated management of access tokens and authorization attributes, resolving the contradiction between maintenance capability and service accessibility.

Inventive Principle:

Principle #23Feedback

2Duration of action of stationary object

If the consumer NF continues using existing access tokens after attribute retirement, then service access remains uninterrupted, but the system cannot properly manage and update authorization attributes

Engineering Contradiction:

Improveaccess token validityVSAvoidauthorization attribute management

Core Design Contradiction:

Duration of action of stationary objectVSAdaptability or versatility

Solution Approach 1:

The NRF receives advance notification from the producer NF about upcoming attribute retirement before it actually occurs. This preliminary action allows the consumer NF to proactively renew access tokens before the retirement time, ensuring continuous service accessibility during maintenance operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where the producer NF notifies the NRF of upcoming attribute retirement, which then communicates this information to the consumer NF. This feedback loop enables coordinated management of access tokens and authorization attributes, resolving the contradiction between maintenance capability and service accessibility.

Inventive Principle:

Principle #23Feedback

3Device complexity

If no synchronization mechanism is implemented between NRF, producer NF, and consumer NF, then the system remains simple and straightforward, but call failures occur when consumer NFs access services from producer NFs with retired attributes

Engineering Contradiction:

Improvesystem structureVSAvoidcall success rate

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The NRF acts as an intermediary that receives retirement notifications from the producer NF and communicates this information to the consumer NF. This intermediary role coordinates the synchronization between different network functions, preventing call failures while maintaining a relatively simple overall system structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system establishes a feedback mechanism where the producer NF notifies the NRF of upcoming attribute retirement, which then communicates this information to the consumer NF. This feedback loop enables coordinated management of access tokens and authorization attributes, resolving the contradiction between maintenance capability and service accessibility.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12137086B2Method for robust token generation in 5G mobile core network

Publication Date: 2024.11.05 CISCO TECHNOLOGY INC

AI summary

A method comprising: at a network function (NF) repository function (NRF) of a core network that includes a consumer NF and a producer NF: issuing, to the consumer NF, an access token used to access services of the producer NF based on allowed authorization attributes of the producer NF; before expiry of the access token, receiving, from the producer NF, an update message that indicates retiring authorization attributes of the allowed authorization attributes, and storing the retiring authorization attributes; before the expiry of the access token, upon receiving, from the consumer NF, an access token request for a new access token, determining not to authorize the access token request based on the retiring authorization attributes; and based on determining, sending, to the consumer NF, an access token error to enable the consumer NF to migrate service requests to a new producer NF before the expiry.