5G I-UPF Routing Rules for Lower Packet Forwarding Delay

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Solution Overview

Problem

The existing route configuration method in 5G networks results in high forwarding delays and inefficiencies when an intermediate UPF (I-UPF) is inserted into the user plane path of a terminal, as it requires packets to be forwarded through multiple unnecessary nodes, especially when communicating with different anchor UPFs.

Innovation Solution

A route configuration method that involves a session management network element determining and generating routing rules for intermediate UPFs to directly communicate with appropriate anchor UPFs, reducing the number of forwarding nodes by establishing direct paths between them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an I-UPF is inserted into the user plane path to ensure service continuity when a terminal moves out of a UPF service scope, then service continuity is maintained, but packet forwarding delay increases due to additional forwarding nodes

Engineering Contradiction:
Improveservice continuityVSAvoidpacket forwarding delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the routing logic by introducing routing rules that differentiate between local packets (destined for terminals in the same service area) and remote packets (destined for terminals in other service areas). The I-UPF uses segmentation to directly forward local packets without unnecessary hops to the A-UPF, while maintaining the A-UPF as an anchor for remote packets, thus resolving the contradiction between service continuity and forwarding delay.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces routing rules as an intermediary mechanism that enables the I-UPF to intelligently determine the optimal forwarding path. These routing rules act as a mediator between the I-UPF and the A-UPF, allowing packets to be forwarded directly to the destination A-UPF when appropriate, rather than always routing through the A-UPF associated with the I-UPF, thereby reducing delay while maintaining service continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If routing rules on the I-UPF forward all uplink packets to the A-UPF corresponding to the PDU session, then the A-UPF can process packets, but forwarding efficiency decreases due to unnecessary intermediate forwarding

Engineering Contradiction:
Improvepacket delivery reliabilityVSAvoidpacket forwarding efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic routing rules on the I-UPF that adaptively select the forwarding destination based on packet characteristics and destination information. Instead of a static routing approach where all packets go through the A-UPF, the routing rules dynamically determine whether to forward packets directly to the destination A-UPF or through the associated A-UPF, optimizing forwarding efficiency while ensuring reliable delivery.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by configuring specific routing rules on the I-UPF that treat different packets differently based on their destination. Packets destined for terminals in the I-UPF's service area receive local optimized routing (direct forwarding), while packets destined for other areas use the standard A-UPF routing path, thereby improving overall forwarding efficiency without compromising delivery reliability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If the I-UPF establishes a tunnel with only the A-UPF corresponding to the PDU session, then the tunnel configuration is simple, but the routing rule cannot efficiently forward packets to terminals served by other A-UPFs

Engineering Contradiction:
Improvetunnel configuration complexityVSAvoidpacket forwarding efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent enhances the universality of the I-UPF by enabling it to serve multiple functions: acting as an anchor for local terminals, forwarding packets for mobile terminals, and efficiently routing packets to other A-UPFs. The routing rules provide multi-functionality by supporting both direct forwarding to destination A-UPFs and indirect forwarding through the associated A-UPF, allowing the I-UPF to handle diverse packet types efficiently without increasing tunnel configuration complexity.

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

Data Source

PatentEP4075868B1Routing configuration method and device
Publication Date: 2025.08.27 HUAWEI TECH CO LTD
  • EP4075868B1 patent drawingFigure 1~2
  • EP4075868B1 patent drawingFigure 3~4
  • EP4075868B1 patent drawingFigure 5~6

AI summary

This application provides a route configuration method and an apparatus, and relates to the field of communications technologies. The method includes: After a first terminal moves out of a service scope of a UPF that currently provides a service, a first SMF inserts a first I-UPF into a user plane path of the first terminal, and configures, for the first I-UPF, a first routing rule corresponding to a second terminal. The first routing rule is used to send a packet whose destination address information is address information of the second terminal to a second A-UPF. The second A-UPF is different from a first A-UPF, the second A-UPF provides an anchor service for the second terminal, and the first A-UPF provides an anchor service for the first terminal. Therefore, a packet whose destination address information is the address information of the second terminal can be directly forwarded by the first I-UPF to the first A-UPF, instead of being forwarded by the first I-UPF to the second A-UPF through the first A-UPF. This shortens a packet forwarding delay.