Core Network Node NSSAA S-NSSAI Association Management

Solution Overview

Problem

In a roaming scenario, it is unclear how a core network node informs a user equipment (UE) which Mapped S-NSSAIs are not available when multiple Mapped S-NSSAIs are associated with a single Serving PLMN S-NSSAI, with some being subject to NSSAA and others not, due to the lack of clear notification mechanisms.

Innovation Solution

A core network node and UE processor configuration that stores associations between Serving PLMN S-NSSAIs and Home PLMN S-NSSAIs, with the node sending specific associations to the UE based on NSSAA feature support, updating the UE's NSSAI storage to reflect available and unavailable S-NSSAIs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If multiple Mapped S-NSSAIs are associated with a single Serving PLMN S-NSSAI without differentiation, then the association management is simplified, but the UE cannot distinguish which S-NSSAIs are available or subject to NSSAA

Engineering Contradiction:

Improveassociation management complexityVSAvoidS-NSSAI availability information

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent segments the association information by creating separate data structures: one for S-NSSAIs not subject to NSSAA and another for S-NSSAIs subject to NSSAA. This segmentation allows the system to maintain simplified overall association management while providing detailed differentiation of S-NSSAI availability status to the UE through separate information elements.

Inventive Principle:

Principle #1Segmentation

2Loss of information

If the core network node sends all Mapped S-NSSAI associations to the UE, then complete information is provided, but the UE cannot determine which S-NSSAIs are actually available without NSSAA support

Engineering Contradiction:

ImproveS-NSSAI association informationVSAvoidUE slice selection operation

Core Design Contradiction:

Loss of informationVSEase of operation

Solution Approach 1:

The patent segments the association information by creating separate data structures: one for S-NSSAIs not subject to NSSAA and another for S-NSSAIs subject to NSSAA. This segmentation allows the system to maintain simplified overall association management while providing detailed differentiation of S-NSSAI availability status to the UE through separate information elements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing different levels of information detail to different UEs based on their capabilities. UEs that do not support NSSAA receive only the S-NSSAIs not subject to NSSAA, while UEs that support NSSAA receive complete information including both categories, allowing each UE to operate with appropriate information granularity.

Inventive Principle:

Principle #3Local quality

3Reliability

If the core network node differentiates between S-NSSAIs subject to NSSAA and those not subject to NSSAA, then accurate slice availability information is provided, but the notification mechanism becomes more complex

Engineering Contradiction:

Improveslice availability notification accuracyVSAvoidnotification mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the association information by creating separate data structures: one for S-NSSAIs not subject to NSSAA and another for S-NSSAIs subject to NSSAA. This segmentation allows the system to maintain simplified overall association management while providing detailed differentiation of S-NSSAI availability status to the UE through separate information elements.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism (the AMF) that manages the complex differentiation logic and presents simplified information to the UE. The AMF acts as a mediator between the complex network slice configuration and the UE, handling the complexity of NSSAA differentiation while providing clear, actionable information to the UE through standardized information elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20230337122A1Core network node, user equipment, and methods therefor

Publication Date: 2023.10.19 NEC CORP

AI summary

A core network node (3) stores a first association between a plurality of Home PLMN S-NSSAIs and a Serving PLMN S-NSSAI. The first association includes a second association between the Serving PLMN S-NSSAI and a Home PLMN S-NSSAI that is not subject to NSSAA, and a third association between the Serving PLMN S-NSSAI and another Home PLMN S-NSSAI subject to NSSAA. If a UE (1) does not support NSSAA feature and if a part of multiple Home PLMN S-NSSAIs presented by the UE (1) is included in the second association and the rest is included in the third association, the core network node sends information containing the second association to the UE (1). This can allow, for example, proper notification of information about a Mapped S-NSSAI available to a UE that does not support NSSAA.