Ethernet Forwarding-Derived PDRs for Dynamic Downlink Mapping
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Solution Overview
Problem
Existing 3GPP systems lack dynamic and efficient mechanisms for determining Protocol Data Unit (PDU) Sessions in the downlink direction of Ethernet traffic, as existing static filtering entries are only applicable to uplink traffic and do not account for externally provided forwarding rules.
Innovation Solution
The Session Management Function (SMF) obtains Ethernet packet forwarding rules from a central controller and converts them into Packet Detection Rules (PDRs), which are then installed in the User Plane Function (UPF) using the N4 interface to dynamically manage downlink traffic forwarding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If static filtering entries are used in the UPF, then uplink traffic forwarding is determined, but downlink traffic forwarding cannot be dynamically managed
Solution Approach 1:
The patent introduces dynamic Packet Detection Rules (PDRs) that can be updated and modified in real-time through the N4 interface between the SMF and UPF. This allows the downlink forwarding behavior to adapt dynamically to changing network conditions and requirements, transforming the static filtering mechanism into a dynamic one that can respond to external forwarding rules from centralized controllers.
Solution Approach 2:
The patent separates the control plane (SMF) from the user plane (UPF) functionality. The SMF is responsible for receiving external forwarding rules from centralized controllers and converting them into PDRs, while the UPF executes these rules for actual packet forwarding. This segmentation allows complex rule management to be handled by the control plane while keeping the user plane simple and efficient.
2Adaptability or versatility
If the UPF acts as an Ethernet bridge with dynamic forwarding rules, then downlink PDU Session determination becomes flexible, but the existing framework compatibility is challenged
Solution Approach 1:
The patent makes the PDR mechanism universal by designing it to handle multiple functions: it can represent traditional static filtering entries for basic forwarding, while also accommodating dynamic external forwarding rules from centralized controllers. The same PDR structure and N4 interface mechanism support both traditional 3GPP forwarding and new Ethernet bridge scenarios, ensuring framework compatibility while enabling flexibility.
Solution Approach 2:
The SMF acts as an intermediary between the centralized controller and the UPF. It receives external forwarding rules from the centralized controller, processes and converts them into the appropriate PDR format, and then installs them in the UPF through the standardized N4 interface. This intermediary role ensures that external rules are properly translated into the UPF's native rule format, maintaining framework compatibility.
3Productivity
If externally provided forwarding rules are integrated into the UPF, then Ethernet packet routing becomes more efficient, but rule conversion and management overhead increases
Solution Approach 1:
The SMF performs preliminary processing of external forwarding rules before installing them in the UPF. It converts the rules into the appropriate PDR format, associates them with the correct PDU sessions, and prepares them for installation. This preliminary action ensures that when rules are installed in the UPF, they are ready for immediate execution, minimizing runtime processing delays and maximizing forwarding efficiency.
Data Source
AI summary
Systems and methods are disclosed herein that relate to obtaining and using Packet Detection Rules (PDRs) in a cellular communications system operating as virtual Ethernet bridge based on Ethernet forwarding information. In one embodiment, a method performed by a User Plane Function (UPF) for enabling a cellular communications system to operate as a virtual Ethernet bridge comprises obtaining a PDR for a Protocol Data Unit (PDU) session in a downlink direction in the cellular communications system. The PDU session is associated with an egress Ethernet port of the virtual Ethernet bridge for the downlink direction, the PDR maps Ethernet packets received at the UPF on an ingress Ethernet port(s) of the virtual Ethernet bridge to the PDU session associated with the egress Ethernet port of the virtual Ethernet bridge, and the PDR is derived from an Ethernet packet forwarding rule of the virtual Ethernet bridge.