5G Registration Area Handling for Non-Uniform Network Slice Support

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Solution Overview

Problem

Current 5G networks restrict UEs from requesting network slices that are rejected for the entire registration area, leading to increased mobility registration updates and signaling load, as they assume allowed S-NSSAIs are uniformly available across the entire registration area, which is not always the case.

Innovation Solution

Introduce the concept of a secondary registration area (SRA) where UEs can request network slices that are not uniformly available across the entire registration area, allowing them to use S-NSSAIs only where they are supported, either within or outside the primary registration area, through the AMF providing SRA information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the network assumes allowed S-NSSAIs are uniformly available across the entire registration area, then the network configuration is simplified, but this leads to increased mobility registration updates and signaling load when slices are actually not uniformly available

Engineering Contradiction:
Improvenetwork configuration complexityVSAvoidsignaling load
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the registration area into multiple tracking areas, each with its own slice availability information. Instead of treating the entire registration area as a uniform zone, the network divides it into smaller units (tracking areas) where slice availability can be independently determined and communicated to UEs, reducing unnecessary registration updates when UEs move within areas where their allowed slices remain available.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by providing slice availability information specific to each tracking area rather than uniformly across the entire registration area. The network configures and communicates tracking area-specific allowed S-NSSAI lists, enabling UEs to determine slice availability locally based on their current tracking area, thereby reducing signaling load when moving between tracking areas with the same slice availability characteristics.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the network provides uniform slice availability across the entire registration area, then UE implementation is simplified, but this restricts UEs from accessing slices available in specific tracking areas outside their registered area

Engineering Contradiction:
ImproveUE operation simplicityVSAvoidslice access flexibility
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements universality by enabling UEs to access allowed slices not only within their registered tracking area but also in other tracking areas where those slices are available. The network provides mechanisms for UEs to determine slice availability in neighboring or target tracking areas, allowing the same UE to operate across multiple tracking areas with different slice availabilities without requiring separate registration procedures.

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

Solution Approach 2:

The patent adds a spatial dimension to slice availability by introducing tracking area-specific allowed S-NSSAI information. Instead of a single uniform slice availability list for the entire registration area, the network provides dimensioned information where slice availability varies by tracking area location, enabling UEs to adapt their slice usage based on their current or target tracking area while maintaining simplified operation through automated network-provided information.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4505770B1Registration with network slices not supported in whole registration area
Publication Date: 2026.03.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4505770B1 patent drawingFigure 1
  • EP4505770B1 patent drawingFigure 2
  • EP4505770B1 patent drawingFigure 3

AI summary

Methods and apparatus in a telecommunication network are provided for handling not only network slices that are supported in the whole RA but network slices that are not supported in the whole RA. More specifically, the methods performed by the wireless device and network node (e.g., AMF in 5G) comprise in a registration procedure between the wireless device and the network node, the wireless device receiving from the network node a first list of one or more tracking areas identifiers (TAI list) for tracking areas representing a registration area (RA) and the associated one or more first network slices that are uniformly available across all the tracking areas of the first TAI list and receiving also at least one second TAI list for second tracking areas and associated one or more second network slices that are uniformly available across all the second tracking areas of the at least one second TAI list, wherein the at least one second TAI list identify the second tracking areas that are at least one of i) a subset of tracking areas included in the first TAI list and ii) different tracking areas that are not included in the first TAI list.