PCF Policy Delivery via AMF Connection State Trigger

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Solution Overview

Problem

In 5G network architecture, signaling overheads are unnecessary when a terminal apparatus is in idle mode, as it does not immediately update policy rules delivered by the Policy Control Function (PCF). However, current methods do not efficiently manage this, leading to increased signaling overheads during policy rule updates.

Innovation Solution

The PCF network element disposes a connection management state trigger in the Access and Mobility Management Function (AMF) to notify the PCF when the terminal apparatus switches to connected mode. This allows the PCF to deliver policy rules only when the terminal apparatus is in connected mode, reducing signaling overheads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the PCF delivers policy rules to the terminal apparatus when it is in idle mode, then the policy rule can be updated timely, but signaling overheads increase unnecessarily

Engineering Contradiction:
Improvepolicy rule update timelinessVSAvoidsignaling overheads
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the policy rule delivery mechanism adaptive to the terminal's connection state. The PCF dynamically adjusts its behavior based on whether the terminal is in connected or idle mode, using the AMF to monitor and report connection state changes. This resolves the contradiction by delivering policy rules only when necessary (connected mode) while avoiding unnecessary signaling during idle mode, thus maintaining reliability when needed and reducing overhead when not needed.

Inventive Principle:
Principle #15Dynamics

2Loss of energy

If the PCF waits for connected mode to deliver policy rules, then signaling overheads are reduced, but policy rule updates are delayed

Engineering Contradiction:
Improvesignaling overheadsVSAvoidpolicy rule update delay
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the AMF monitor and track the terminal's connection state in advance. The AMF is pre-configured with the terminal's identity and is ready to immediately notify the PCF when the terminal transitions to connected mode. This ensures that while policy rules are delivered only in connected mode (reducing overhead), the update delay is minimized because the network is already prepared to deliver the rules as soon as the terminal becomes available.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the AMF continuously monitors terminal connection state, then policy rules can be delivered timely when terminal becomes connected, but network complexity increases

Engineering Contradiction:
Improvepolicy rule delivery efficiencyVSAvoidnetwork element complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies universality by leveraging the AMF's existing multi-functional role in the 5G architecture. The AMF already performs access authentication, mobility management, and connection management functions. By adding the capability to monitor connection state for policy rule delivery triggers, the patent extends an existing universal network element to handle multiple functions, thereby improving policy rule delivery efficiency without significantly increasing overall network complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3806537B1Policy transmission method, PCF network element and computer storage medium
Publication Date: 2025.04.16 HUAWEI TECH CO LTD
  • EP3806537B1 patent drawingFigure 1~2
  • EP3806537B1 patent drawingFigure 3~4
  • EP3806537B1 patent drawingFigure 5

AI summary

This application provides a policy transmission method, a PCF network element, and a computer storage medium. The method includes: obtaining, by a policy control PCF network element, a connection management state of a terminal apparatus, where the connection management state includes a connected mode or an idle mode; and sending, by the PCF, policy rule information to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode. In technical solutions provided in this application, signaling overheads can be reduced in a communication process in which the PCF delivers the policy rule to the terminal apparatus.