RPC-Based PFCP Message Service for 5G SMF Connection Sharing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The complexity of managing multiple N4 connections between Session Management Function (SMF) instances and User Plane Functions (UPFs) in a 5G network, resulting from the concept of NF Sets where multiple SMF instances share user context data, leads to overcomplicated connection management.

Innovation Solution

Implementing a Remote Procedure Call (RPC)-based protocol, such as gRPC, to provide a Packet Forwarding Control Protocol (PFCP) message service that facilitates PFCP connection sharing among SMF instances, using a shared termination function to minimize connections between SMFs and UPFs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple SMF instances within an SMF Set establish separate N4 connections to each UPF instance, then each SMF instance can independently manage PDU sessions, but the number of N4 connections multiplies and connection management becomes overcomplicated

Engineering Contradiction:

ImproveSMF instance independenceVSAvoidconnection management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a termination function as an intermediary component that centralizes N4 connection management. This termination function acts as a mediator between multiple SMF instances and UPF instances, allowing SMF instances to share common N4 connections through the termination function rather than establishing separate direct connections to each UPF, thereby reducing overall connection complexity while maintaining SMF independence

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If a shared termination function is introduced to minimize N4 connections, then connection management complexity is reduced, but the system requires an additional intermediary component

Engineering Contradiction:

Improveconnection management complexityVSAvoidSMF instance independence

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The termination function is designed with multi-functionality to handle various PFCP message types (session establishment, modification, deletion, etc.) and serve multiple SMF instances simultaneously. This universal design allows a single termination function instance to perform the work of multiple dedicated termination points, reducing connection complexity while maintaining full SMF instance independence through standardized interface protocols

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20230014876A1Packet forwarding control protocol (PFCP) message service using a remote procedure call (RPC) based protocol suitable for PFCP connection sharing

Publication Date: 2023.01.19 CISCO TECHNOLOGY INC

AI summary

A computing device may be configured to provide a shared N4 termination function for a plurality of Session Management Function (SMF) instances of an SMF Set and interface with one or more User Plane Function (UPF) instances. To achieve this, the computing device may operate a server configured with a Remote Procedure Call (RPC)-based protocol (e.g. gRPC Remote Procedure Call or “gRPC”) for a Packet Forwarding Control Protocol (PFCP) message service for serving a plurality of client stubs respectively situated at the plurality of SMF instances. The server may perform processing associated with each client stub by receiving an RPC-based protocol message which indicates a request, unpacking the RPC-based protocol message for obtaining PFCP message request data, and operating or interfacing with a PFCP message handling client for sending a PFCP message having the PFCP message request data to an indicated one of the UPF instances.