PDU Session Slice Switching Through AMF-Guided Alternative NSSAI
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Solution Overview
Problem
Conventional techniques for changing network slices in wireless communications systems perform slice remapping transparently to the user equipment (UE) non-access stratum (NAS) layer, failing to account for how the UE processes alternative network slices for different protocol data unit (PDU) sessions, and existing methods do not effectively manage UE reconfiguration for network slice changes.
Innovation Solution
A network entity, such as the access and mobility management function (AMF), determines an alternative network slice and configures the UE to use it for PDU session establishment, indicating the availability of an alternative slice during registration procedures and allowing the UE to request it, even if it is not part of the configured network slice selection assistance information (NSSAI).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional techniques perform slice remapping transparently to the UE NAS layer, then network slice changes can be made, but the UE cannot properly process alternative network slices for different PDU sessions and reconfiguration management is ineffective
Solution Approach 1:
The patent introduces the AMF as an intermediary between the network and UE for managing alternative network slices. The AMF receives PDU session establishment requests, determines alternative S-NSSAIs, and communicates with the UE through standardized NAS signaling, thereby mediating the complex slice remapping process and making it manageable for the UE.
Solution Approach 2:
The patent segments the network slice management into distinct components: the AMF handles alternative slice determination and signaling, the SMF handles PDU session management, and the UE handles session establishment. This segmentation allows each component to focus on specific tasks, improving overall manageability.
2Productivity
If the AMF determines and configures alternative network slices for UE, then efficient PDU session management is achieved, but additional signaling and configuration overhead is introduced
Solution Approach 1:
The patent makes the AMF multi-functional by having it handle both traditional mobility management functions and the new alternative network slice determination function. This universality avoids introducing additional dedicated signaling entities, thereby managing complexity while maintaining productivity.
Solution Approach 2:
The AMF performs preliminary determination of alternative S-NSSAIs during the registration procedure or before PDU session establishment. By preparing alternative slice information in advance, the actual session establishment process is streamlined, improving efficiency while distributing signaling load.
3Adaptability or versatility
If the UE is allowed to request alternative S-NSSAI not in configured NSSAI, then network slice adaptability is improved, but network control and slice selection management becomes more complex
Solution Approach 1:
The patent implements feedback mechanisms where the UE indicates its alternative slice requests to the AMF, and the AMF responds with acceptance or rejection based on network policies and availability. This feedback loop maintains network control while allowing UE adaptability in slice selection.
Data Source
AI summary
Various aspects of the present disclosure relate to changing network slices for a protocol data unit (PDU) sessions. An apparatus receives a first signaling as a registration request from a user equipment (UE) to register with a first network slice, and the apparatus transmits a second signaling indicating acceptance of the registration and an allowability of the UE to register with an alternative network slice. The UE transmits the first signaling to request a registration with the first network slice, and receives the second signaling indicating the registration with the first network slice and an allowability to register with the alternative network slice. The UE transmits a third signaling to establish a first PDU session on the first network slice.