N3IWF Interworking for Untrusted Non-3GPP Access

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Solution Overview

Problem

The complexity of integrating standalone untrusted non-3GPP access networks with mobile core networks in wireless communications, particularly due to the need for specific interfaces and network elements, limits the deployment scenarios and excludes many IoT devices from accessing NextGen core networks without implementing NAS protocols.

Innovation Solution

A method and apparatus using a Non-3GPP Interworking Function (N3IWF) to provide interworking between non-3GPP access networks and the mobile core network, enabling devices to attach to the NextGen core network using common AN-CN interfaces and allowing legacy and IoT devices to access the network without supporting NAS protocols, by acting as a proxy for authentication and protocol conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If specific interfaces and network elements are used for integrating standalone untrusted non-3GPP access networks with mobile core networks, then interworking capability is achieved, but system complexity increases

Engineering Contradiction:
Improveinterworking capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a Non-3GPP Interworking Function (N3IWF) as an intermediary network element that mediates between non-3GPP access networks and the 5G core network. This intermediary handles protocol conversion, authentication, and session management, enabling standalone untrusted non-3GPP access networks to interwork with the mobile core network without requiring complex modifications to existing network elements or access networks.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If common AN-CN interfaces are used for all access networks, then architecture simplification is achieved, but support for legacy devices without NAS protocol capability is limited

Engineering Contradiction:
Improvearchitecture complexityVSAvoiddevice compatibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The N3IWF acts as a protocol mediator that translates between NAS protocols used by the 5G core network and alternative authentication protocols used by legacy devices. This allows legacy devices without NAS protocol capability to access the network through common AN-CN interfaces while maintaining architecture simplification.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the authentication and access functions by separating them into distinct modules within the N3IWF. This segmentation allows the system to handle different device types (NAS-capable and NAS-legacy) through different protocol handling paths while maintaining a unified interface architecture.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If LTE-WLAN Aggregation is used for WLAN integration, then network element complexity is reduced, but deployment scenarios are limited due to coverage requirements

Engineering Contradiction:
Improvenetwork element complexityVSAvoiddeployment scenario flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent extracts the WLAN integration functionality from the LTE network infrastructure by introducing a standalone N3IWF that operates independently of E-UTRAN coverage. This extraction allows WLAN access networks to connect directly to the 5G core network without requiring integration with LTE base stations, thereby expanding deployment scenarios to areas without LTE coverage while keeping network element complexity manageable.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3513582B1Method and apparatus for attaching a remote unit to a mobile core network via a standalone untrusted non-3GPP access network
Publication Date: 2020.10.21 MOTOROLA MOBILITY LLC
  • EP3513582B1 patent drawingFigure 1
  • EP3513582B1 patent drawingFigure 2
  • EP3513582B1 patent drawingFigure 3

AI summary

A remote unit can be communicated with over a non-3GPP access network via a first network interface (610). A mobile core network can be communicated with via a second network interface and a third network interface (620, 630). A secure connection request to establish a secure connection can be received via the first network interface (640). The secure connection with the remote unit can be established via the first network interface (670, 680). Signaling data can be relayed between the secure connection and the second network interface when the secure connection request is associated with the first capability (672). A data connection can be established via the third network interface on behalf of the remote unit and user data can be relayed between the secure connection and the data connection when the secure connection request is associated with the second capability (682).