UE Identity Synchronization for RRC Inactive Paging Across Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the existing 5G communication network, UEs in RRC Inactive state with CM-CONNECTED mode experience synchronization issues with mobile identities when transitioning between 3GPP and non-3GPP access, leading to failed paging procedures and incorrect routing due to mismatched temporary identities.
Innovation Solution
The proposed solution involves synchronizing temporary identities by releasing RRC resources and transitioning to RRC Idle state when the UE's temporary identity changes over non-3GPP access, updating the NG-RAN with the new identity, and using RRC messages to ensure correct paging and routing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the UE maintains RRC Inactive state with CM-CONNECTED mode to enable fast service resumption, then service continuity is improved, but temporary identity synchronization between UE and network deteriorates when GUTI changes over non-3GPP access
Solution Approach 1:
The network performs preliminary actions by updating the S-TMSI in the RAN before the UE needs to be paged. When the AMF detects that the GUTI has changed over non-3GPP access, it proactively updates the S-TMSI in the RAN via N2 signaling, ensuring that the RAN has the correct temporary identity before paging is needed. This preliminary update prevents the identity desynchronization problem.
Solution Approach 2:
The system implements feedback mechanisms where the AMF monitors GUTI changes over non-3GPP access and provides feedback to the RAN to update the S-TMSI accordingly. This feedback loop ensures that the RAN always has the current temporary identity for UEs in RRC Inactive state, maintaining synchronization without requiring the UE to transition to RRC Connected state.
2Device complexity
If the UE uses the same 5G-GUTI for both 3GPP and non-3GPP access to simplify identity management, then device complexity is reduced, but paging reliability deteriorates when the GUTI changes over non-3GPP access
Solution Approach 1:
The AMF acts as an intermediary that manages the temporary identity synchronization between the UE, RAN, and non-3GPP access networks. When the GUTI changes over non-3GPP access, the AMF intermediates by updating the S-TMSI in the RAN via N2 signaling, ensuring that all entities have consistent temporary identities without requiring complex UE-side identity management.
Solution Approach 2:
The invention extracts the S-TMSI update function from the UE and places it in the network (AMF and RAN). Instead of requiring the UE to manage and update multiple temporary identities, the network extracts and manages the S-TMSI independently, updating it in the RAN when GUTI changes occur over non-3GPP access. This simplifies UE complexity while maintaining paging reliability.
3Quantity of substance
If the NG-RAN stores the old S-TMSI to maintain RRC Inactive state resources, then resource efficiency is improved, but paging accuracy deteriorates when the UE's GUTI changes
Solution Approach 1:
The network performs preliminary updates of the S-TMSI in the RAN before paging operations are needed. When the AMF detects a GUTI change over non-3GPP access, it proactively updates the S-TMSI in the RAN via N2 signaling, ensuring that the RAN stores the correct temporary identity before any paging attempt. This prevents the RAN from using outdated S-TMSI values.
Solution Approach 2:
The AMF implements a feedback mechanism that monitors GUTI changes and provides feedback to the RAN to update the stored S-TMSI. This feedback ensures that the RAN always has the current temporary identity for UEs in RRC Inactive state, maintaining both resource efficiency and paging accuracy simultaneously.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure relates to synchronizing a temporary identity in the UE and the network when the UE is RRC Inactive state over 3GPP access and temporary identity of the UE is changed over a Non-3GPP access in a scenario when the UE is connected to the same AMF via 3GPP and non-3GPP access.