EAP-5G Authentication Across Non-3GPP Access Networks

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Solution Overview

Problem

In 3GPP 5G networks, there is no mechanism for a UE to register (authenticate and connect) with a 5G core network via a non-3GPP access network.

Innovation Solution

A new EAP authentication method, referred to as EAP-5G, is introduced, allowing UEs to register with the 5G core network over non-3GPP access networks by reusing the same message types used for 3GPP access networks, using EAP Expanded packets with vendor-ID pointing to 3GPP and vendor data containing messages defined for EAP-5G.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a UE connects to a non-3GPP access network, then the UE can access the network using alternative access methods, but there is no mechanism for the UE to register with the 5G core network via the non-3GPP access network

Engineering Contradiction:

Improveaccess network compatibilityVSAvoidauthentication mechanism

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies universality by enabling the EAP authentication protocol to handle both traditional EAP authentication and 5G NAS message authentication through a unified framework. The EAP-5G method allows the same authentication infrastructure to serve multiple access networks (3GPP and non-3GPP), making the system multi-functional without requiring separate authentication mechanisms for each access type.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces an intermediary mechanism where EAP messages act as a mediator between the non-3GPP access network and the 5G core network authentication functions. The EAP-5G method translates and transports NAS messages through the EAP framework, enabling communication between systems with different protocol requirements without direct integration.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the same NAS message types are reused for non-3GPP access, then message compatibility is improved, but protocol complexity increases due to EAP encapsulation requirements

Engineering Contradiction:

Improvemessage compatibilityVSAvoidauthentication protocol

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the nesting principle by encapsulating NAS messages within EAP message structures. The 5G NAS authentication messages are nested inside EAP-5G information elements, which are themselves contained within EAP authentication exchanges. This layered nesting allows the preservation of NAS message formats while adapting them for transport through the EAP protocol framework required by non-3GPP networks.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentEP3855767B1A method to authenticate with a mobile communication network

Publication Date: 2025.10.01 MOTOROLA MOBILITY LLC

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AI summary

Apparatuses, methods, and systems are disclosed for authenticating with a mobile communication network. One apparatus 300 includes a processor 305, a first transceiver 325 that communicates with a mobile communication network via a first access network, and a second transceiver 330 that communicates with the mobile communication network via a second access network. The processor 305 sends 710 a request to start authentication via the second access network and receives 715 an extensible authentication protocol ("EAP") request with a first expanded type via the second access network. The processor 305 sends 720 an EAP response via the second access network, the EAP response comprising the first expanded type, a first set of parameters, and a first message. Here, the first message is a same type of message usable to establish a connection with the mobile communication network over the first access network.