Sub-Domain Code Routing for Concealed 5G NF Instance Selection

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Solution Overview

Problem

The service-based architecture in 5G core networks faces challenges in efficiently selecting the appropriate network function instance to provide services to subscribers, especially when multiple instances of a network function are deployed across different sub-domains, and the subscription identifier is concealed.

Innovation Solution

The network equipment selects a provider NF instance based on a sub-domain code, determining the sub-domain to which the subscriber is assigned, even when the subscription identifier is concealed, using a sub-domain code field in the subscription concealed identifier (SUCI) to identify the appropriate NF instance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple instances of network function are deployed across different sub-domains, then service coverage and reliability are improved, but the complexity of selecting the appropriate NF instance increases

Engineering Contradiction:
Improveservice reliabilityVSAvoidNF instance selection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The home network is divided into multiple sub-domains, each with its own NF instances. The SUCI is segmented to include a sub-domain code that identifies which sub-domain the subscriber belongs to. This segmentation allows the network to efficiently route service requests to the appropriate sub-domain without requiring complex global selection logic.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sub-domain code embedded in the SUCI acts as an intermediary that bridges the subscriber and the appropriate NF instance. Instead of directly matching subscribers to NF instances using complex criteria, the sub-domain code provides a simple key that the NRF uses to quickly identify and select the correct NF instance in the appropriate sub-domain.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If subscription identifier is concealed for security, then subscriber privacy and security are improved, but the ability to identify and select appropriate NF instances deteriorates

Engineering Contradiction:
Improvesubscriber securityVSAvoidsubscription identifier information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The subscription identifier information is segmented into two parts: the concealed portion (for security) and the sub-domain code (for routing). The sub-domain code is extracted from the concealed identifier and embedded in the SUCI, allowing it to be visible for routing purposes while the rest of the subscription identifier remains concealed for security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sub-domain code is extracted from the concealed subscription identifier and placed in the SUCI. This extracted portion contains just enough information (sub-domain identification) to enable NF instance selection, while the critical subscriber identification information remains concealed and is not exposed in the SUCI.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If NF service discovery uses NRF with multiple NF instances, then service availability is improved, but the discovery and selection process becomes less efficient

Engineering Contradiction:
Improveservice availabilityVSAvoidNF discovery efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The sub-domain code serves as an intermediary key that enables the NRF to efficiently filter and select NF instances. Instead of the NRF having to evaluate multiple NF instances against complex subscriber criteria, the sub-domain code provides a direct mapping that quickly identifies the appropriate NF instance, dramatically improving discovery efficiency while maintaining full service availability across multiple instances.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4093093B1Network function instance selection
Publication Date: 2025.10.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4093093B1 patent drawingFigure 1
  • EP4093093B1 patent drawingFigure 2A~2B
  • EP4093093B1 patent drawingFigure 2C

AI summary

Method 300 performed by network equipment 40 in a wireless communication network 10 and corresponding network equipment 40, the method including the steps of obtaining a sub-domain code 32 indicating a certain sub-domain, from among multiple sub-domains of a home network of a subscriber 13, to which the subscriber 13 is assigned (Block 310). The method 300 may also include transmitting information that configures a user equipment 12 of the subscriber 13, or an integrated circuit card 12A associated with the subscriber 13, with the obtained sub-domain code 32 (Block 320).