PGW Session Re-initiation via MME Handover Feedback

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Solution Overview

Problem

The existing EPS system technology cannot accurately determine when a handover procedure is completed, leading to inaccurate timing for re-initiating session management processes, resulting in repeated rejections and resource wastage.

Innovation Solution

A method and device that enable the Packet Data Gateway (PGW) to initiate and re-initiate session management processes by starting a timer based on information from the Mobility Management Entity (MME), with the option to receive an instruction message for accurate handover completion timing, ensuring timely re-initiation of session management processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PGW uses locally-configured timer to re-initiate session management process, then PGW can autonomously retry the procedure, but the timing is inaccurate causing repeated rejections or unnecessary waiting

Engineering Contradiction:
Improvere-initiation timing accuracyVSAvoidwaiting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The MME sends a notification message to the PGW when the handover procedure is completed, providing feedback information about the actual completion time. This allows the PGW to adjust its timer and re-initiate the session management process at the accurate moment, avoiding both repeated rejections and unnecessary waiting.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The MME predicts the handover completion time in advance and notifies the PGW before the actual completion occurs. This preliminary notification allows the PGW to set its timer accurately and prepare for timely re-initiation of the session management process.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If PGW re-initiates session management process immediately after timer timeout, then response speed is improved, but handover may still be in progress causing repeated rejections

Engineering Contradiction:
Improvere-initiation speedVSAvoidhandover completion confirmation
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The MME provides feedback to the PGW about the actual handover completion status through notification messages. This feedback mechanism ensures that the PGW only re-initiates the session management process when the handover is truly completed, maintaining high reliability while enabling fast re-initiation.

Inventive Principle:
Principle #23Feedback

3Reliability

If PGW waits for extended period before re-initiation, then handover completion is ensured, but UE may go idle causing re-paging and resource waste

Engineering Contradiction:
Improvehandover completion certaintyVSAvoidcommunication resource waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The MME predicts and notifies the PGW about the handover completion time in advance. This preliminary action allows the PGW to set an accurate timer and re-initiate the session management process at the optimal moment, preventing UE from going idle and avoiding re-paging overhead.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses the MME's handover management information to automatically adjust the PGW's timer, enabling the PGW to self-regulate its re-initiation timing without manual intervention or excessive waiting periods, thus avoiding resource waste.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2629555B1Method and device for reinitiating session management process of EPS system
Publication Date: 2019.07.17 CHINA ACAD OF TELECOMM TECH
  • EP2629555B1 patent drawingFigure 1~2
  • EP2629555B1 patent drawingFigure 3
  • EP2629555B1 patent drawingFigure 4

AI summary

The present invention discloses a method and device for re-initiating EPS session management procedure. The application of technical solution proposed through embodiment of this invention can enable PGW to determine whether handover operation on MME side is completed through timing by timer and/or instruction message on MME side; if it is completed, re-initiate session management process of corresponding EPS system, thus enabling PGW to timely re-initiate EPS session management procedure, reducing the time for unnecessary waiting, and avoiding resource waste caused by repeated rejection of EPS session management procedure re-initiated when handover procedure is not completed, so as to improve reconnection efficiency of session management process of EPS system and reduce waste of communication resource.