Network Slice-Aware PLMN Selection for Roaming UE Compatibility
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Solution Overview
Problem
Existing 5G network technologies fail to ensure that roaming user equipment can access network slices that support required features, leading to hindered functionality and user experience due to unsupported S-NSSAIs in preferred PLMNs.
Innovation Solution
Implementing a network slice aware PLMN selection method that utilizes a preferred PLMN list and a network slice aware PLMN exception list to prioritize and switch between PLMNs based on supported network functions, ensuring seamless access to required network slices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If user equipment uses a preferred PLMN list for roaming selection, then connection establishment speed is improved, but network slice compatibility is worsened because preferred PLMNs may not support required S-NSSAIs
Solution Approach 1:
The network provides both a preferred PLMN list and a network slice aware PLMN exception list in advance through SoR signaling. The UE prepares to use the preferred list for fast connection while having the exception list ready as a pre-configured backup that guarantees support for required S-NSSAIs, eliminating the need for trial-and-error PLMN selection.
Solution Approach 2:
The network slice aware PLMN exception list acts as an intermediary mechanism between the preferred PLMN selection process and the requirement for network slice compatibility. When the preferred PLMN cannot provide required network slices, the UE switches to the exception list which serves as a mediator ensuring both connectivity and slice support.
2Reliability
If user equipment switches between PLMNs to find supported network slices, then network slice compatibility is improved, but connection stability is worsened due to frequent reselection
Solution Approach 1:
The network provides the network slice aware PLMN exception list in advance through SoR signaling, containing PLMNs that are pre-verified to support required S-NSSAIs. This preliminary action prevents the UE from attempting connections to incompatible PLMNs, eliminating the need for frequent reselection and connection instability.
Solution Approach 2:
The system implements feedback through the SoR procedure where the network provides information about PLMN slice compatibility. The UE uses this feedback to make informed PLMN selection decisions, avoiding unstable connections to PLMNs that cannot support required network slices.
3Ease of operation
If user equipment attempts to access network slices in preferred PLMNs without verification, then ease of operation is improved, but functionality is worsened when S-NSSAIs are not supported
Solution Approach 1:
The network slice aware PLMN exception list serves as an intermediary that bridges automatic PLMN selection with network slice access capability. The list contains PLMNs that are pre-identified as supporting required S-NSSAIs, allowing the UE to automatically select compatible networks without manual verification while ensuring slice access capability is maintained.
Data Source
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AI summary
A method, apparatus, and computer program product for detecting and switching between locally available PLMNs accessible to a user equipment based on a Preferred PLMN List and a Network Slice Aware PLMN Exceptions List configured by a HPLMN. The user equipment connects to a preferred VPLMN. The user equipment determines that a particular network function is not supported by the connected preferred VPLMN. The user equipment determines that another VPLMN is required to support the particular network function. The user equipment then switches to a non-preferred VPLMN which supports the particular network function. Once the particular network function is no longer necessary for the user equipment to perform a required task, the user equipment switches back a preferred VPLMN