Roaming Control for IMS APN via Dynamic Gateway Selection

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Solution Overview

Problem

Current systems face challenges in providing seamless multimedia services, particularly IMS services, during roaming scenarios where the visited network may not support IMS voice, leading to disruptions in services like VoLTE and RCS, due to lack of IMS roaming agreements between operators.

Innovation Solution

A method that involves a second network node in the visited communication network receiving subscription information from a first network node, allowing it to select either a V-PDN GW in the visited network or a H-PDN GW in the home network based on IMS or LTE roaming agreements, ensuring uninterrupted multimedia services by routing the IMS APN to a network that supports the necessary agreements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the visited network is used for multimedia services during roaming, then service coverage is improved, but service reliability deteriorates when IMS roaming agreements are not established

Engineering Contradiction:
Improveservice coverageVSAvoidservice reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism (the network node selecting between V-PDN GW and H-PDN GW based on roaming agreement status) that mediates between the visited network's service coverage and the reliability requirement. When IMS roaming agreements are absent, the system routes through the home network's PDN GW, ensuring reliable service delivery while still allowing access via the visited network's infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the network routing parameter (selecting between V-PDN GW and H-PDN GW) based on the presence or absence of IMS roaming agreements. This parameter change allows the system to adapt to different roaming scenarios, maintaining service reliability by switching to the home network route when necessary while preserving service coverage through the visited network route when agreements exist.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If home routing is used for IMS APN, then service reliability is improved, but service accessibility deteriorates in visited networks without IMS support

Engineering Contradiction:
Improveservice reliabilityVSAvoidservice accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent implements a dynamic routing mechanism that automatically adjusts the network path based on the visited network's IMS support capability. The system transitions between home routing and visited network routing dynamically, ensuring that service reliability is maintained through home routing when needed while service accessibility is improved by utilizing the visited network when it supports IMS services.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If visited network routing is used, then service accessibility is improved, but service continuity deteriorates when IMS roaming agreements are absent

Engineering Contradiction:
Improveservice accessibilityVSAvoidservice continuity
Core Design Contradiction:
Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The network node acts as an intermediary that monitors the presence of IMS roaming agreements and automatically switches routing paths to maintain service continuity. When agreements are absent, it intermediates by routing through the home network's PDN GW, preventing service interruption while still allowing initial access through the visited network.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2664192B1Roaming control for IMS apn
Publication Date: 2016.06.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2664192B1 patent drawingFigure 1
  • EP2664192B1 patent drawingFigure 2
  • EP2664192B1 patent drawingFigure 3

AI summary

The embodiments herein relate to a method in a second node (310) in a visited network (300v). The visited network (300v) is visited by a UE (301 ). The second node (310) receives a message comprising subscription information. The subscription information comprises a parameter indicating that the UE (301 ) is allowed to use a multimedia service in the home (300h) or the visited network (300v). The second node (310) selects a serving gateway (308) in the visited network (300v). Based on the parameter, the second node (310) selects a visited PDN gateway (305v), in the visited network (300v) when the UE (301 ) is allowed to use the multimedia service in the visited network (300v). Based on the parameter, the second node (310) selects a home PDN gateway (305h) in the home network (300h) when the UE (301 ) is allowed to use the multimedia service in the home network (300h).