Sx Node PDR Management for 5G Control-Plane Signaling
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Solution Overview
Problem
Current Sx protocol requires repetitive signaling and memory storage of Packet Detection Rules (PDRs) for all active and new sessions, leading to inefficient CP-UP signaling and increased memory usage, as each active Sx session needs to receive identical PDRs applicable to all sessions.
Innovation Solution
Introduction of a new Sx Node PDR Management procedure that allows the Control Plane to instruct Node PDRs applicable to all or a group of Sx sessions, using new Information Elements like NodePDRId and GroupedSessionIdentity, reducing the need for repeated signaling and storage by handling Node PDRs separately from traditional session-level PDRs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Control Plane sends PDRs to the User Plane for each active Sx session, then each session can be properly managed with appropriate packet detection rules, but the signaling overhead increases significantly when the same PDR needs to be applied to multiple sessions
Solution Approach 1:
The patent introduces a Node PDR that can be applied universally across multiple Sx sessions simultaneously. Instead of creating separate PDR instances for each session, a single Node PDR configuration can cover multiple sessions, reducing redundant signaling while maintaining proper packet detection for each session.
Solution Approach 2:
The patent merges multiple session-specific PDR configurations into a single Node PDR that applies to multiple sessions. By combining the common PDR elements at the node level rather than repeating them per session, the signaling overhead is reduced while preserving session-specific customization capabilities through session-level PDR extensions.
2Reliability
If the User Plane stores PDRs for all active Sx sessions, then complete packet detection capability is maintained for each session, but the memory footprint increases when identical PDRs are stored repeatedly
Solution Approach 1:
The patent implements a reference-based copying mechanism where the User Plane stores a single instance of common PDR data at the node level, and multiple sessions reference this shared copy. When a Node PDR needs to be applied to multiple sessions, rather than duplicating the entire PDR structure, the system creates lightweight references to the shared PDR data, significantly reducing memory consumption while maintaining complete packet detection capability.
Solution Approach 2:
The Node PDR structure is designed to serve multiple sessions simultaneously with a single configuration instance. The User Plane maintains one copy of the PDR data that can be universally applied across all sessions that reference it, eliminating redundant storage while ensuring each session has access to the complete packet detection rules it needs.
3Reliability
If the Control Plane triggers Sx Session Modification procedures for each active session to add a new PDR, then the PDR is properly applied to each session, but the signaling complexity and processing time increase
Solution Approach 1:
The patent allows the Control Plane to pre-configure Node PDRs at the user plane node before they are needed by specific sessions. By performing the PDR configuration in advance at the node level, when multiple sessions need the same PDR, the Control Plane can simply activate the pre-configured Node PDR for multiple sessions simultaneously rather than individually modifying each session, significantly reducing the time and signaling required for session modifications.
Solution Approach 2:
The patent merges multiple individual session modification operations into a single Node PDR configuration operation. Instead of triggering separate Sx Session Modification procedures for each session that needs a PDR, the system combines these operations by creating one Node PDR that applies to all relevant sessions, reducing both the signaling complexity and the total time required for PDR deployment.
4Reliability
If identical PDRs are transmitted repeatedly to the User Plane for multiple sessions, then each session receives its required rules, but the signaling efficiency decreases
Solution Approach 1:
The Node PDR mechanism provides universal PDR delivery capability that serves multiple sessions with a single configuration transmission. The Control Plane can instruct the User Plane to apply a Node PDR to multiple sessions simultaneously, ensuring each session receives the required packet detection rules while eliminating redundant transmissions and improving signaling efficiency.
Solution Approach 2:
The system uses reference-based copying where a single PDR configuration is transmitted once to the User Plane, and multiple sessions are configured to reference this shared PDR instance. This approach ensures complete PDR delivery to all sessions that need it while dramatically reducing the number of signaling messages required compared to transmitting identical PDRs separately for each session.
Data Source
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AI summary
The embodiments herein relate to Sx protocol extension to support node PDR. In one embodiment, there proposes a method (500) in a first network node (301) configured as control plane function (CPF). The first network node (301) is coupled to a second network node (302) configured as user plane function (UPF) via an Sx interface. The method (500) comprising transmitting (S501) a message associated with a Packet Detection Rule (PDR) to the second network node (302) via the Sx interface, wherein the PDR is applicable to more than one Sx session. With embodiments herein, the CPF-UPF signaling throughput can be minimized significantly, and the memory footprint per Sx session can be decreased.