Shared NSSF for Roaming Network Slice Selection

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Solution Overview

Problem

Current network slicing technologies require a Network Slice Selection Function (NSSF) to be deployed in each network slice instance, which is inefficient, and there is a lack of description on how a shared NSSF can perform slice selection for users roaming between slices.

Innovation Solution

A method where a single NSSF is shared among multiple network slices in a core network, receiving user information and determining a target network slice based on a preset roaming policy, and sending a response message with identification information for slice selection, allowing seamless roaming between slices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If NSSF is deployed in every network slice instance, then slice selection function is available for each slice, but device complexity and deployment cost increase

Engineering Contradiction:
Improveslice selection availabilityVSAvoidNSSF deployment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple network slice instances share a single NSSF network element instead of each slice having its own NSSF. The shared NSSF receives slice selection requests from AMF, determines the target network slice based on user information and roaming policies, and returns the selection result, thereby reducing overall system complexity while maintaining slice selection functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shared NSSF network element serves multiple network slices simultaneously, performing slice selection functions for different slices through a single instance. This universal NSSF handles requests from multiple slices using preset roaming policies and user information to determine appropriate target slices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If NSSF is shared by multiple network slices, then deployment efficiency improves, but slice selection capability for roaming users becomes uncertain

Engineering Contradiction:
Improvedeployment efficiencyVSAvoidroaming slice selection capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The shared NSSF is pre-configured with roaming policies that define slice selection rules for different scenarios. When a user roams between slices, the NSSF uses these preset policies along with user information to automatically determine the target network slice, ensuring reliable slice selection during roaming without requiring additional real-time configuration.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If current NSSF deployment method is used, then slice selection can be performed, but resource utilization is inefficient

Engineering Contradiction:
Improveslice selection functionVSAvoidNSSF instance quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

Multiple network slice instances share a single NSSF network element instead of each slice having its own NSSF. This consolidation reduces the total number of NSSF instances from multiple (one per slice) to a single shared instance, improving resource utilization while maintaining slice selection functionality through centralized management.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4013128B1Method, apparatus, and system for selecting network slice, and storage medium
Publication Date: 2025.01.08 ZTE CORP
  • EP4013128B1 patent drawingFigure 1~2
  • EP4013128B1 patent drawingFigure 3~4
  • EP4013128B1 patent drawingFigure 5~6

AI summary

A network slice selection method, apparatus, and system, and computer-readable storage medium are disclosed. The method may include: receiving a slice selection request, where the slice selection request is adopted for requesting to select a network slice for a roaming user, and the slice selection request comprises user information (101); determining a target network slice according to a preset roaming policy and the user information (102); and sending a response message for the slice selection request, where the response message carries identification information of the target network slice (103).