SMF Session Parameter Coordination for Multi-PDU Session Inactivity
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Solution Overview
Problem
The existing 5G network architecture lacks flexibility and scalability to efficiently manage multiple PDU sessions and network slices, leading to unclear methods for deriving and configuring session parameters, such as QoS parameters and UE/Session Inactivity timers, especially in scenarios where a UE is attached to multiple UP-GWs or network slice instances.
Innovation Solution
The Session Management Function (SMF) maintains and coordinates PDU session parameters across multiple control plane entities, deriving and updating session parameters based on subscription and policy rules, and coordinates with UPFs and RAN nodes to manage independent session states and QoS policies, allowing simultaneous activation of multiple sessions with reduced signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing 5G network architecture is used to manage multiple PDU sessions and network slices, then the network can support multiple connections, but the architecture lacks flexibility and scalability leading to unclear methods for deriving and configuring session parameters
Solution Approach 1:
The patent segments the session parameter management by introducing separate functional entities: the Session Management Function (SMF) for deriving session parameters and the User Plane Function (UPF) for enforcing QoS policies. This segmentation allows independent optimization of control plane and user plane, improving flexibility and scalability while reducing the complexity of unified parameter management across multiple PDU sessions and network slices.
Solution Approach 2:
The SMF acts as an intermediary between the control plane and user plane, deriving session parameters including QoS profiles and forwarding them to the UPF. This intermediary role enables centralized parameter derivation while distributed enforcement, resolving the contradiction by providing clear parameter configuration methods without increasing overall system complexity.
2Reliability
If session parameters are managed centrally without clear derivation methods, then parameter consistency can be maintained, but signaling overhead increases and activation/deactivation efficiency decreases
Solution Approach 1:
The SMF derives session parameters including QoS profiles in advance during session establishment and stores them locally. When sessions need to be activated or deactivated, the pre-derived parameters are readily available, eliminating the need for repeated signaling exchanges and reducing activation time while maintaining parameter consistency through centralized derivation.
Solution Approach 2:
Each SMF instance derives session parameters locally based on subscription data and network policies specific to its managed sessions. This local derivation approach maintains parameter consistency within each session context while reducing signaling overhead, as parameters are determined at the point of need rather than through centralized coordination for every session change.
3Adaptability or versatility
If multiple UP-GWs are attached to a UE, then connectivity options increase, but the management of session states and QoS policies becomes unclear and complex
Solution Approach 1:
The patent applies segmentation by associating each PDU session with a specific SMF instance, which in turn manages the session state and QoS policies for that session. This one-to-one mapping between SMF and PDU session simplifies the management of multiple UP-GWs, as each session's control plane functions are handled by a dedicated SMF, making session state management straightforward despite multiple connectivity options.
Solution Approach 2:
The SMF is designed as a universal function that can manage session parameters and QoS policies for multiple PDU sessions across different UP-GWs. This multi-functionality allows the same SMF entity to handle diverse session types and connectivity scenarios, simplifying operation by providing a unified management approach for multiple UP-GW attachments.
4Productivity
If session parameters are dynamically updated for each activation, then session optimization is improved, but signaling overhead increases
Solution Approach 1:
The SMF derives session parameters including QoS profiles preliminarily during session establishment and stores them for reuse. During subsequent activations, the SMF retrieves pre-derived parameters rather than regenerating them, reducing signaling overhead while maintaining the ability to optimize sessions dynamically when actual traffic patterns are known.
Solution Approach 2:
The patent enables dynamic parameter changes by allowing the SMF to update session parameters based on actual traffic conditions and network state. The SMF can modify QoS profiles and other session parameters dynamically while leveraging pre-derived parameters as a baseline, achieving session optimization without requiring complete parameter re-negotiation and reducing signaling overhead.
Data Source
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AI summary
The method proposes to establish at least one session between the User Equipment and the Session Management Function node, and initiate session deactivation for a session indicated by the User Plane Function node, upon detection inactivity of User Plane connection for the session for a period by the User Plane Function node.