V-SMF Handover Context Update for Roaming EASDF Selection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The issue arises in roaming scenarios when determining whether to reuse or select a new V-SMF (Visited-Session Management Function) and how to handle the context update during such changes.

Innovation Solution

The changed V-SMF notifies the old V-SMF if a new EASDF (Equivalent Access Service Data Function) is selected, or updates the context if reusing the existing EASDF.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a new EASDF is selected during V-SMF change, then service continuity and roaming reliability are improved, but signaling overhead and network complexity increase due to notification between old and new V-SMF

Engineering Contradiction:
Improveroaming reliabilityVSAvoidnetwork complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the new V-SMF notifies the old V-SMF about EASDF selection decisions. This feedback loop ensures that both V-SMF instances have consistent information about the current EASDF assignment, enabling reliable service continuity during roaming while maintaining coordinated network state management.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses the V-SMF change process as an intermediary mechanism to transfer EASDF selection information from the old V-SMF to the new V-SMF. This intermediary approach allows seamless handover of roaming context without requiring direct involvement of other network functions, thus improving reliability while controlling complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If context update is performed during V-SMF change, then service continuity is maintained, but processing time and signaling overhead increase

Engineering Contradiction:
Improveservice continuityVSAvoidcontext update time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs context update actions preliminarily during the V-SMF change process itself, rather than as a separate subsequent step. By integrating the EASDF context transfer into the handover procedure, the patent maintains service continuity while minimizing additional processing time and signaling overhead.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If V-SMF changes during roaming, then network flexibility and adaptability are improved, but context management complexity and information loss risk increase

Engineering Contradiction:
Improvenetwork adaptabilityVSAvoidcontext information
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The notification mechanism from new V-SMF to old V-SMF serves as a feedback loop that prevents context information loss during V-SMF changes. This feedback ensures that the old V-SMF can properly release resources and that the new V-SMF has complete context information, thereby maintaining network adaptability while preventing information loss.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4664991A1Management method of easdf
Publication Date: 2025.12.17 LG ELECTRONICS INC
  • EP4664991A1 patent drawingFigure 1
  • EP4664991A1 patent drawingFigure 2
  • EP4664991A1 patent drawingFigure 3

AI summary

One disclosure of the present disclosure provides a method by which V-SMF performs communication. The method comprises the steps of: wherein a handover of a V-SMF for a UE (User Equipment) is performed from a source V-SMF to the target V-SMF, receiving, from the source V-SMF, a context related to session for the UE, based on the handover; selecting a new V-EASDF (V-Edge Application Server Discovery Function), based on a PLMN (Public Land Mobile Network selection) of the target V-SMF being different from a PLMN of the source V-SMF.