Local IP Gateway Home Agent for Mobile Session Continuity

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Solution Overview

Problem

Current cellular networks face challenges in maintaining IP session continuity when a user equipment (UE) moves out of the local IP breakout service area, as the new base station may be in an incorrect IP subnet, breaking the active session due to routing issues and inability to switch IP addresses without service disruption.

Innovation Solution

A method is implemented to provide session continuation by informing the UE about neighboring macro cells where the local breakout service can continue, executing a handover process from a source base station to a target base station in a neighboring macro cell, and controlling user plane tunneling between the target base station and the local packet switched network where the local Internet protocol gateway is located, ensuring uninterrupted service.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If local IP breakout service is provided within a limited service area using a local IP gateway, then optimized local routing and direct connectivity are achieved, but user mobility is limited and IP session continuity is broken when moving out of the service area

Engineering Contradiction:
Improvelocal routing efficiencyVSAvoiduser mobility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a home agent (HA) as an intermediary component in the local IP gateway that mediates between the mobile terminal and the network. The HA maintains the home IP address of the mobile terminal and establishes tunnel connections to care-of addresses, enabling seamless mobility management while preserving local routing efficiency within the service area.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent adds an IP layer abstraction dimension to the existing radio access network architecture. By introducing Mobile IP protocols at the network layer, the system enables global mobility management while maintaining local breakout capabilities, effectively adding a new dimension of operation to the traditional flat network architecture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a SAE gateway is used to provide global roaming and mobility support, then IP session continuity is maintained, but local routing optimization is lost and traffic must traverse through the centralized gateway

Engineering Contradiction:
Improveglobal mobility supportVSAvoidrouting efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent segments the network architecture into multiple functional components: local IP gateways for local breakout services, home agents for mobility management, and SAE gateways for core network functions. This segmentation allows traffic to be routed locally when possible while maintaining global mobility support, avoiding the bottleneck of centralized gateway processing for all traffic.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by enabling different routing behaviors for different traffic types and locations. Within the local IP breakout service area, traffic is routed directly through the local IP gateway for optimized performance. When moving outside the service area, the system automatically transitions to using the SAE gateway, providing location-aware routing optimization.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If IP address is changed when moving to a new base station outside the local service area, then connectivity to the new network is established, but the active LBO session is broken due to routing issues

Engineering Contradiction:
Improvenetwork connectivityVSAvoidsession continuity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent performs preliminary action by pre-configuring the home agent with the mobile terminal's home IP address before mobility events occur. The home agent proactively establishes tunnel connections to potential care-of addresses and maintains binding information, so when the mobile terminal moves and changes IP addresses, the session continuity is automatically maintained without disruption to active services.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent ensures continuity of useful action by maintaining the mobile terminal's home IP address assignment throughout mobility events. The home agent continuously manages the binding between the home IP address and current care-of address, ensuring that active LBO sessions can continue without interruption even as the terminal moves between different base stations and network locations.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP2201799B1Session continuation for the handover of a local breakout service from a local internet protocol gateway
Publication Date: 2013.11.06 NOKIA SOLUTIONS & NETWORKS OY
  • EP2201799B1 patent drawingFigure 1~2
  • EP2201799B1 patent drawingFigure 3
  • EP2201799B1 patent drawingFigure 4

AI summary

There is provided a method comprising: providing a local breakout service to an Internet protocol gateway while retaining user access control and a remote Internet protocol gateway of a packet core network of a radio network for a mobile terminal; providing information on neighboring macro cells in which the local breakout service can continue, the macro ceils belonging to a network using another tracking area than that of the serving cell of the mobile terminal; executing a handover process of the mobile terminal from a source base station in the serving cell of the mobile terminal to a target base station in a neighboring macro cell; and providing session continuation of the mobile terminal local breakout service traffic in the neighboring macro cell by controlling user plane tunneling between the target base station and the local packet switched network from which an Internet protocol address for the local breakout service was assigned.