Isolated Network Slice Selection via AMF Routing

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Solution Overview

Problem

Current 5G network slicing technologies face challenges in isolating and co-existing network slices, particularly in selecting appropriate Access and Mobility Management Functions (AMFs) to manage isolated network slices, which leads to co-existence issues when they interact with non-isolated slices.

Innovation Solution

The introduction of a 'requested isolated NSSAI' parameter in RRC signaling to guide the selection of an AMF that supports isolated network slices, with embodiments including AMF re-routing before and after authentication, and procedures for isolated network slice updates to manage compatibility and subscription.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a default AMF is used to handle all network slice requests, then the system is simple to operate, but isolated network slices cannot be properly selected and managed

Engineering Contradiction:

ImproveAMF selection simplicityVSAvoidisolated network slice selection capability

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent segments the AMF selection process into two distinct paths: one for isolated network slices and one for non-isolated slices. The RAN node separately handles Requested NSSAI (non-isolated) and Requested isolated NSSAI (isolated), routing them to appropriate AMFs based on slice type. This segmentation enables proper isolation management while maintaining operational simplicity through clear separation of concerns.

Inventive Principle:

Principle #1Segmentation

2Reliability

If isolated network slices are implemented with dedicated AMFs, then network slice isolation is achieved, but co-existence issues arise when isolated and non-isolated slices interact

Engineering Contradiction:

Improvenetwork slice isolationVSAvoidAMF co-existence management

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces the RAN node as an intermediary that mediates between the UE and multiple AMFs. The RAN node receives both Requested NSSAI and Requested isolated NSSAI, determines the appropriate target AMF based on slice type, and routes requests accordingly. This intermediary approach enables reliable slice isolation while simplifying co-existence management by centralizing the routing logic in the RAN node.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If the RAN routes all NAS signalling to a default AMF, then the system maintains simplicity, but isolated network slice selection cannot be performed

Engineering Contradiction:

Improvesignaling routing simplicityVSAvoidnetwork slice selection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements dynamic routing behavior in the RAN node that adapts based on the type of network slice requested. The RAN node dynamically selects between routing to a default AMF (for non-isolated slices) or a dedicated isolated AMF (for isolated slices) based on the presence and content of Requested isolated NSSAI. This dynamic approach maintains signaling routing simplicity for common cases while enabling precise slice selection when needed.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3777340B1Isolated network slice selection

Publication Date: 2024.05.01 NEC CORP

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AI summary

The current invention proposes procedures for selection of isolated network slices and rerouting to isolated network slices. It explores different use cases of successful isolated network slice selection and also the fallback from isolated network slice when it is not available.