5G LAN Internal Interface for Local Switching

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Solution Overview

Problem

Current specifications for 5G networks lack detailed procedures for implementing different routing policies, such as N6-based, Local Switch, and Nx-based policies, which are essential for efficient traffic routing between 5G-LAN group members without relying on external data networks.

Innovation Solution

The proposed solution involves the Session Management Function (SMF) configuring Packet Forwarding Control Protocol (PFCP) signaling to enable UPFs to perform local switching and Nx-based forwarding, using new forwarding rules and interfaces like '5G LAN Internal' and '5G LAN Nx' to route traffic directly between UPFs, thereby bypassing external networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If traffic routing between 5G-LAN group members goes through external data networks (N6-based routing), then network compatibility and external network access are ensured, but traffic routing efficiency and latency increase

Engineering Contradiction:
Improvetraffic routing speedVSAvoidrouting policy complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent segments the routing architecture into multiple paths: external N6-based routing for general traffic requiring external network access, and internal UPF-based routing for 5G-LAN group traffic. This segmentation allows traffic to be routed through the most appropriate path based on destination, improving speed for local traffic while maintaining compatibility for external traffic.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The UPF (User Plane Function) acts as an intermediary between 5G-LAN group members, enabling direct local switching of traffic within the 5G core network. This intermediary capability allows traffic to bypass external data networks and be routed directly between UPFs serving LAN group members, improving routing efficiency and reducing latency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If local switching is implemented within UPF for 5G-LAN traffic, then traffic routing efficiency improves and external network involvement is eliminated, but device complexity and configuration requirements increase

Engineering Contradiction:
Improvetraffic transmission timeVSAvoidUPF configuration complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The SMF (Session Management Function) performs preliminary configuration of the UPF by installing Packet Detection Rules (PDRs) and Forwarding Action Rules (FARs) before traffic flows. This preliminary action enables the UPF to perform local switching automatically based on pre-configured rules, reducing transmission time while managing complexity through automated configuration management.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces new parameters and indicators in PFCP (Packet Forwarding Control Protocol) signaling, such as the '5G-LAN Internal' destination interface indicator and Network Instance parameters. These parameter changes enable the UPF to distinguish 5G-LAN traffic and apply appropriate local switching rules, improving transmission efficiency while maintaining standardized configuration procedures.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If multiple routing policies (N6-based, Local Switch, Nx-based) are supported, then network flexibility and service adaptability improve, but specification complexity and implementation difficulty increase

Engineering Contradiction:
Improverouting policy adaptabilityVSAvoidspecification complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic routing policy selection where the SMF determines the appropriate routing approach (N6-based, Local Switch, or Nx-based) based on real-time traffic characteristics, 5G-LAN group membership, and network conditions. This dynamic adaptation allows the system to support multiple routing policies without requiring complex static configuration, improving versatility while managing specification complexity through automated decision-making.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The UPF is designed with multi-functionality to support all three routing policies (N6-based, Local Switch, and Nx-based) within a single network element. This universal capability allows the same infrastructure to handle diverse routing requirements, improving adaptability while reducing the need for separate specialized devices for each routing mode.

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

4Speed

If UPFs are deployed close to UEs for low latency applications, then Round Trip Time decreases and response speed improves, but network control complexity and signaling overhead increase

Engineering Contradiction:
ImproveRound Trip TimeVSAvoidnetwork control complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The SMF performs preliminary configuration of distributed UPFs by pre-installing PDRs and FARs that enable local switching. This preliminary action allows deployed UPFs to autonomously perform low-latency local switching without requiring complex real-time control signaling, reducing RTT while managing control complexity through advance configuration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where UPFs report traffic patterns and switching performance to the SMF, which uses this information to optimize routing policies and configuration. This feedback loop enables the system to adapt to changing conditions and maintain optimal performance across distributed UPFs, managing control complexity through intelligent monitoring and adjustment.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3895385B1Methods and apparatuses for supporting a local area network (LAN)
Publication Date: 2024.06.26 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3895385B1 patent drawingFigure 1
  • EP3895385B1 patent drawingFigure 2A~2B
  • EP3895385B1 patent drawingFigure 3A

AI summary

The disclosure relates to systems and methods enabling an SMF (208) to control new forwarding behavior in the UPF (206) to support locally switched and Nx-based forwarding.