AMF Relocation for Network Slice Adaptation

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in resource utilization due to limitations in network-triggered changes of network slices, particularly in managing network slice changes that require AMF relocation and PDU session management.

Innovation Solution

A method and apparatus for determining and modifying current-allowed network slices based on network triggers, identifying new-allowed slices, selecting a target AMF accessible by the source AMF, and triggering AMF relocation, including procedures for managing active PDU sessions and generating status reports to facilitate seamless network slice changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If network-triggered changes of network slices are implemented, then network adaptability and service continuity are improved, but system complexity and resource management overhead increase

Engineering Contradiction:
Improvenetwork slice adaptabilityVSAvoidAMF relocation management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system performs preliminary identification of new-allowed network slices and selection of target AMF before actual relocation is needed. The source AMF proactively determines the target AMF based on new-allowed NSSAI, preparing the relocation path in advance to enable smooth transitions when network slice changes are triggered.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The source AMF acts as an intermediary that coordinates the relocation process between the UE and target AMF. It manages the PDU session status reports, coordinates the handover of network slice management responsibilities, and ensures seamless transition by mediating the interaction between old and new network slice management entities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If AMF relocation is performed for network slice changes, then service continuity is maintained, but signaling overhead and network resources consumption increase

Engineering Contradiction:
Improveservice continuityVSAvoidsignaling overhead
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system maintains continuous service by ensuring PDU sessions are properly transferred and maintained during AMF relocation. The target AMF receives PDU session status reports from the source AMF and continues managing active sessions without interruption, ensuring the useful action of data transmission continues seamlessly during the relocation process.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The UE actively participates in the relocation process by providing PDU session status information to the source AMF, which then forwards relevant session information to the target AMF. This self-service approach allows the UE to contribute to the relocation process, reducing the signaling burden on the network by having the UE provide necessary session state information.

Inventive Principle:
Principle #25Self-service

3Productivity

If multiple network slices are managed by a single AMF, then resource utilization is improved, but the difficulty of managing slice-specific configurations and access control increases

Engineering Contradiction:
Improveresource utilizationVSAvoidslice configuration management difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system segments network slice management by allowing different AMFs to specialize in managing specific network slices or slice types. When relocation is triggered, the UE is transferred to a target AMF that is better suited for managing the new-allowed network slices, dividing the management responsibility across multiple specialized AMFs rather than concentrating all slice management in a single AMF.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically changes the AMF assignment parameter based on the network slice configuration. When the allowed NSSAI changes, the system evaluates whether a different AMF should manage the slices and adjusts the AMF assignment accordingly, allowing flexible reconfiguration of slice management assignments without fixed one-to-one mappings.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3636004B1Relocation of access and mobility management function (AMF) upon a network-triggered change of network slices supported for a user equipment
Publication Date: 2024.11.27 QUALCOMM INC
  • EP3636004B1 patent drawingFigure 1
  • EP3636004B1 patent drawingFigure 2
  • EP3636004B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A method may include determining to modify current-allowed network slices used by a user equipment (UE) based on a network-trigger; identifying new-allowed network slices for the UE based on the determining; selecting a target access and mobility management function (AMF) based on the new-allowed network slices, the target AMF is accessible by the source AMF; and triggering an AMF relocation based on the selecting.