PDN Connection Gateway Switching for Optimal Routing

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Solution Overview

Problem

Current methods lack a seamless way to switch an established PDN connection to a new PDN connection using a more optimal gateway, leading to suboptimal communication paths due to the movement of user equipment (UE) and the presence of closer gateway devices.

Innovation Solution

A terminal device and communication control method that allow for the establishment of a first PDN connection with a first gateway, initiation of a service request to transition to a second gateway, and management of IP addresses to ensure seamless communication path switching, using a SERVICE REQUEST message and associated procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the UE maintains the PDN connection with the initially selected LGW while moving, then the PDN connection stability is improved, but the communication path optimality deteriorates as closer gateways become available

Engineering Contradiction:

ImprovePDN connection stabilityVSAvoidcommunication path optimality

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic gateway selection by allowing the UE to initiate service request procedures that trigger PDN connection re-establishment with different gateways. The system transitions from a static gateway assignment to a dynamic selection process where the UE can request connection to alternative gateways based on current location and network conditions, resolving the contradiction between connection stability and path optimality.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the state parameter of the PDN connection from a fixed gateway association to a flexible state where the gateway can be changed through service request procedures. By modifying the connection parameters to allow re-establishment with different gateways while maintaining the same PDN connection identity, the system achieves both stability (continuous connection) and adaptability (optimal gateway selection).

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the UE switches to a new PDN connection with a closer gateway, then the communication path optimality is improved, but the disconnection risk increases

Engineering Contradiction:

Improvecommunication path optimalityVSAvoidcommunication continuity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by having the UE initiate a service request procedure before actually switching gateways. This procedural approach allows the network to prepare for the gateway change in advance, establishing the new connection path while maintaining the old one until the switch is complete, thereby minimizing disconnection risk while achieving optimal routing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The service request procedure acts as an intermediary mechanism between the UE's desire to switch gateways and the actual connection change. This intermediary process coordinates the gateway switch through standardized network procedures, ensuring that the transition is managed smoothly with minimal disruption to communication continuity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3220712B1Terminal device, base station device, MME, and communications control method

Publication Date: 2022.01.19 SHARP KK

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AI summary

An MME detects that a PDN connection is not effective and changes from a non-optimal gateway to a bearer established in a PDN connection using a more optimal gateway as an endpoint node. This configuration allows an already-established PDN connection to switch to a new PDN connection using the more optimal gateway, which achieves optimal communication control for continuing communication of UE.