N3IWF AMF Selection for Non-Cellular 5G Core Access

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Solution Overview

Problem

In the 5G Core Network, accessing a specific network slice from a User Equipment (UE) performing non-cellular communication is challenging due to the need to correctly select the Access and Mobility Management Function (AMF) for non-3GPP access methods.

Innovation Solution

The proposed solution involves an N3IWF that selects the appropriate AMF based on network identification information, using AMF information stored in an AMF information storing unit, and facilitates access to the correct slice by redirecting the access request, ensuring reliable non-3GPP access for UE performing non-cellular communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If non-cellular communication is used to access the 5G Core Network, then access flexibility and alternative connectivity options are improved, but the complexity of correctly selecting the appropriate AMF for non-3GPP access increases

Engineering Contradiction:
Improveaccess flexibilityVSAvoidAMF selection complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The N3IWF acts as an intermediary between the UE performing non-cellular communication and the AMF. It receives access requests from the UE, selects the appropriate AMF based on the requested slice information, and forwards the request to the selected AMF. This mediator approach simplifies the UE's task by handling the complex AMF selection process centrally at the N3IWF, thereby maintaining access flexibility while reducing selection complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary action by pre-establishing the mapping relationships between network slices and AMFs in the N3IWF. The N3IWF stores AMF information including slice identification and corresponding AMF identifiers in advance. When an access request arrives, the N3IWF can quickly match the requested slice with the pre-stored information to select the appropriate AMF, avoiding complex real-time decision-making and reducing selection complexity.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the N3IWF stores detailed AMF information for multiple slices, then the precision of slice-specific AMF selection is improved, but the information storage requirements and system complexity increase

Engineering Contradiction:
Improveslice-specific AMF selection precisionVSAvoidinformation storage requirements
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The N3IWF implements local quality by storing AMF information specifically organized by slice identification. Each slice has its corresponding AMF identifier stored in the AMF information storing unit. This localized storage approach ensures that only the necessary information for each specific slice is maintained, achieving precise slice-specific AMF selection without storing redundant information across all slices, thus balancing precision with storage efficiency.

Inventive Principle:
Principle #3Local quality

3Reliability

If the N3IWF redirects access requests to the correct AMF based on slice identification, then the reliability of network slice access is improved, but the processing time and complexity of the access request handling increase

Engineering Contradiction:
Improvenetwork slice access reliabilityVSAvoidaccess request processing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The N3IWF performs preliminary action by pre-storing the mapping relationships between slice identifiers and AMF identifiers in the AMF information storing unit. When an access request arrives with requested slice information, the N3IWF can immediately perform a simple lookup in the pre-configured mapping table to identify the correct AMF, rather than performing complex real-time analysis. This preliminary preparation significantly reduces processing time while maintaining reliable slice-specific AMF selection.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3654701B1Network access method and communication system
Publication Date: 2023.12.06 NTT DOCOMO INC
  • EP3654701B1 patent drawingFigure 1
  • EP3654701B1 patent drawingFigure 2
  • EP3654701B1 patent drawingFigure 3

AI summary

An object is that, in a mobile communication, a communication terminal that performs a non-cellular communication can access a service network that provides a service. A network access method to be performed by a communication system 8 forming a core network of the mobile communication and to cause a UE 7 performing the non-cellular communication to access a slice 5 providing the service comprises: an acquisition step of acquiring from the UE 7, terminal identification information identifying the UE 7; and an access step of referring to correspondence information correlating the UE 7 and the slice 5, and causing the UE 7 to access the slice 5 correlated with the UE 7 identified by the terminal identification information acquired in the acquisition step.