5G LADN Service Request Handling via I-SMF Rejection

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Solution Overview

Problem

The integration of Local Area Data Networks (LADNs) and Intermediate Session Management Functions (I-SMFs) in 5G mobile radio communication systems poses challenges in handling service requests, particularly when a mobile terminal moves between areas served by different session management functions, leading to issues with session establishment and management.

Innovation Solution

A communication network component that receives service requests from mobile terminals and rejects them if the terminal is located in a part of the LADN that requires an intermediate session management function, determining the terminal's location and initiating service only if it is within the service area of a standard session management function, and updating the terminal's configuration to exclude unavailable LADNs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mobile terminal moves from an SMF service area to an I-SMF service area within an LADN, then the terminal can access the LADN service area, but session management becomes complex and service requests may be rejected

Engineering Contradiction:
ImproveLADN service area coverageVSAvoidsession management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The LADN service area is segmented into multiple zones, each served by different SMF types (SMF or I-SMF). The network divides the service area based on mobility patterns and service requirements, allowing terminals to be served by appropriate SMF types in different regions, thus managing complexity while maintaining coverage

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The AMF acts as an intermediary between the mobile terminal and the SMF/I-SMF. It determines whether the terminal is in an I-SMF service area and selectively routes service requests to the appropriate SMF type, simplifying the terminal's view while managing the complexity of having multiple SMF types in the network

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the network rejects service requests from terminals in I-SMF service areas, then session management control is maintained, but service availability is reduced

Engineering Contradiction:
Improvesession management controlVSAvoidservice availability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The network dynamically adjusts service request handling based on the terminal's location. Service requests are rejected only when the terminal is in an I-SMF service area and the request type is not supported, while allowing requests when the terminal is in an SMF service area or when I-SMF supports the request type. This dynamic approach maintains control while preserving service availability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different service request handling policies are applied in different LADN service area zones. In SMF service areas, all request types are handled by the SMF. In I-SMF service areas, only supported request types are handled, while others are rejected. This local differentiation maintains session management control while maximizing service availability where possible

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the network supports all service request types in I-SMF service areas, then service availability is maintained, but session management complexity increases

Engineering Contradiction:
Improveservice availabilityVSAvoidsession management complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The AMF serves as an intermediary that filters and routes service requests based on the terminal's location and the I-SMF's capabilities. It prevents unsupported request types from reaching the I-SMF, thereby maintaining service availability for supported requests while avoiding the complexity of implementing all request types in the I-SMF

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3737199B1Communication network component and method for handling a service request
Publication Date: 2023.04.19 NTT DOCOMO INC
  • EP3737199B1 patent drawingFigure 1
  • EP3737199B1 patent drawingFigure 2
  • EP3737199B1 patent drawingFigure 3

AI summary

According to one embodiment, a communication network component is described comprising a receiver configured to receive a request for a communication service of a local area data network from a mobile terminal and a controller configured to reject the request if the mobile terminal is located in a part of the local area data network that requires an intermediate session management function to serve the mobile terminal.