5G/4G Session Continuity Using ePDG Registration Checks

Solution Overview

Problem

Current 5G networks face challenges in providing seamless session continuity with 4G/LTE networks due to unnecessary message traffic and latency caused by session continuity subscription and retrieval processes, particularly through S6a/SWm interfaces, which can be reduced by optimizing UE registration with the evolved Packet Data Gateway (ePDG) and leveraging UE user or subscriber registration information to avoid redundant messaging.

Innovation Solution

Implementing a system that restricts session continuity functionality by avoiding additional message traffic through the N26 interface, leveraging UE registration information to determine if ePDG/AAA registration exists, and utilizing the N26 interface for session continuity between 5G and 4G/LTE networks, thereby reducing unnecessary S6a/SWm-triggered messaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If session continuity subscription and retrieval processes are implemented through S6a/SWm interfaces, then session continuity between 5G and 4G/LTE networks is ensured, but unnecessary message traffic and latency increase

Engineering Contradiction:

Improvesession continuityVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts and removes unnecessary session continuity subscription and retrieval processes through S6a/SWm interfaces. By identifying that these processes are redundant when UE registration information is available, the system eliminates the harmful messaging while preserving essential session continuity functionality through optimized pathways.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary actions by checking UE registration information with ePDG/AAA before initiating session continuity processes. This advance verification allows the system to determine whether session continuity subscription is necessary, preventing unnecessary message traffic from being generated in the first place.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If session continuity subscription and retrieval processes are implemented through S6a/SWm interfaces, then session continuity between 5G and 4G/LTE networks is ensured, but redundant messaging increases network traffic

Engineering Contradiction:

Improvesession continuityVSAvoidmessage traffic

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts and removes unnecessary session continuity subscription and retrieval processes through S6a/SWm interfaces. By identifying that these processes are redundant when UE registration information is available, the system eliminates the harmful messaging while preserving essential session continuity functionality through optimized pathways.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The system applies partial action by selectively performing session continuity subscription only when necessary - specifically when UE registration information indicates that ePDG/AAA registration does not exist. This conditional approach avoids excessive messaging while ensuring session continuity is maintained when required.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If additional message traffic through N26 interface is avoided, then network efficiency is improved, but session continuity management complexity increases

Engineering Contradiction:

Improvenetwork efficiencyVSAvoidsession continuity management

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by checking UE registration information with ePDG/AAA before initiating session continuity processes. This advance verification allows the system to determine whether session continuity subscription is necessary, preventing unnecessary message traffic from being generated in the first place.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback mechanisms by continuously monitoring UE registration information and using this feedback to determine whether session continuity subscription is needed. This closed-loop approach allows the system to dynamically adjust its behavior based on current network state, maintaining efficiency without excessive complexity.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12520118B24G/5G session continuity management optimization

Publication Date: 2026.01.06 HEWLETT PACKARD ENTERPRISE DEV LP

AI summary

Systems and methods are provided for optimizing session continuity management during 5th Generation (5G) and 4G/Long Term Evolution (LTE) interworking. Conventional 4G/LTE and 5G interworking involves session continuity subscription or retrieval operations to obtain the latest mobility data for a user equipment (UE) attempting to attach to a particular communications network. These operations include exchanging various messages can be avoided by determining the existence of an Authentication, Authorization, Accounting (AAA)/evolved Packet Data Network Gateway (ePDG) registration (among other conditions).