UE PDU Session Continuity for 5G Local Network Handover
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Solution Overview
Problem
In 5G networks, user equipment (UE) experiences disruptions in service data flow continuity when moving between a local network connected via a 5G residential gateway (5G-RG) and a 5G telecommunications network, as existing handover procedures require new IP address assignment, breaking the previous connection and complicating session management due to the lack of dedicated session management contexts for UEs behind the 5G-RG.
Innovation Solution
The UE is configured to manage connection continuity by transmitting PDU session modification requests and access requests between gateway devices, allowing it to branch or nest service data flows and quality of service information between session management contexts stored in the telecommunications network, enabling seamless handover without requiring new IP address assignments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE performs handover procedure using existing 3GPP methods, then connectivity can be maintained during movement, but service data flow continuity is disrupted because new IP address assignment breaks the previous connection
Solution Approach 1:
The patent segments the session management by creating separate PDU sessions for different access types (3GPP and non-3GPP). Each PDU session maintains its own session management context and IP address assignment, allowing independent management of service data flows on each access type without interfering with the other.
Solution Approach 2:
The patent implements nesting by allowing a UE to have multiple PDU sessions where one session's session management context can be transferred or mirrored to another. The service data flow information is nested within session management contexts that can be moved between different PDU sessions, enabling continuity when switching access types.
2Device complexity
If a UE behind 5G-RG uses a single PDU session for the gateway, then administrative processing is reduced, but the UE lacks dedicated session management context making handover impossible
Solution Approach 1:
The patent makes the session management system universal by enabling session management contexts to serve multiple purposes: they can be associated with a single PDU session for simplified management, or transferred to dedicated PDU sessions when handover is needed. The same session management infrastructure supports both aggregated and dedicated session scenarios.
Solution Approach 2:
The patent introduces dynamic session management where the UE can establish dedicated PDU sessions on-demand when handover is required. The session management context can be dynamically transferred from the gateway's aggregated session to the UE's dedicated session, providing adaptability while maintaining simplicity when the dedicated session is not needed.
3Ease of operation
If a new PDU session is created for handover, then the UE can establish connectivity, but the previous connection is broken causing service disruption
Solution Approach 1:
The patent performs preliminary action by establishing a dedicated PDU session for the target access type before breaking the connection to the source access type. The session management context is prepared and transferred in advance, so when the handover occurs, the service data flow continuity is maintained through the pre-established session rather than being lost.
Data Source
AI summary
One aspect of this disclosure pertains to a UE configured for controlling connection continuity in a system comprising a first gateway device having a first established PDU session with a telecommunications network storing a first session management context for the first gateway device associated with the first established PDU session and providing a local network for a plurality of UEs using the first established PDU session of the first gateway device and a further device having a second established PDU session with the telecommunications network storing a second session management context associated with the second established PDU session. The UE is configured to control connection continuity by transmitting a PDU session modification request to the telecommunications network comprising a reference to first PDU session information in the first session management context stored in the telecommunications network for the UE to include at least part of the first PDU session information in the second session management context. Alternatively or in addition, the UE may be configure to transmit an access request to the first gateway device comprising a reference to second PDU session information in the second session management context stored in the telecommunications network to include at least part of the second PDU session information in the first session management context.