Policy-Based AMF Selection Using NSSAI Availability and Load
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Solution Overview
Problem
The existing 3GPP service architecture does not specify how to optimize AMF selection using NSSAI availability information, leading to inefficient allocation of network slice resources and AMF resources.
Innovation Solution
A method and system for policy-based AMF selection using NSSAI availability information, involving a network slice selection function (NSSF) that obtains and prioritizes AMFs based on their supported NSSAIs and load percentages to generate a prioritized list for efficient AMF selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the NSSF provides NSSAI availability information but does not specify how to use it for AMF selection, then the information is available but resource allocation efficiency deteriorates
Solution Approach 1:
The NSSF performs preliminary actions by obtaining NSSAI availability information from the NSSAI availability service before AMF selection is needed. This information is stored and prepared in advance, so when an AMF selection request occurs, the NSSF can immediately use the pre-obtained NSSAI availability data to make optimized selection decisions, rather than gathering information at the moment of selection.
Solution Approach 2:
The system implements feedback by using the obtained NSSAI availability information to inform and optimize the AMF selection process. The NSSF continuously monitors and utilizes NSSAI availability data to make informed decisions about which AMF should serve which UEs, creating a feedback loop where availability information directly influences selection outcomes and improves overall resource allocation efficiency.
2Ease of operation
If default AMF selection is used without optimization, then AMF selection is simple but network slice resource utilization deteriorates
Solution Approach 1:
The system changes the selection parameters by incorporating NSSAI availability information into the AMF selection criteria. Instead of using only basic parameters like UE location and access type, the NSSF now considers the availability status of different network slices across multiple AMFs, dynamically adjusting selection based on current slice availability to optimize resource utilization while maintaining operational simplicity.
3Adaptability or versatility
If multiple AMFs support the same network slice services, then service coverage is improved but selection optimization deteriorates without prioritization
Solution Approach 1:
The system segments the AMF selection process by creating a prioritized list that divides multiple capable AMFs into hierarchical tiers. Instead of treating all AMFs equally, the NSSF segments them based on their NSSAI availability status, with AMFs having better slice availability ranked higher. This segmentation allows the system to maintain service coverage through multiple AMFs while optimizing selection by preferring higher-priority AMFs.
Data Source
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AI summary
A method for providing for policy-based access and mobility management function (AMF) selection using network slice selection assistance information (NSSAI) availability information obtained from an NSSAI availability service includes, at a network slice selection function (NSSF) including at least one processor, obtaining, from an NSSAI availability service, NSSAI availability information regarding a plurality of AMFs. The method further includes receiving, from a first AMF, a network slice selection request specifying a network slice service requested by a user equipment (UE). The method further includes generating, based on the NSSAI availability information and the network slice service requested by the UE, a prioritized list including an identity of at least one AMF for supporting the network slice service. The method further includes communicating the prioritized list to the first AMF.