MAC-Rewriting Packet Distribution for Fast UPF Session Migration

Solution Overview

Problem

Mobile operators face lengthy failover times and service disruptions due to N:M redundancy models in user plane functions (UPFs), and session management function (SMF) lacks the ability to manage UPF health and perform optimal load balancing, leading to suboptimal cost benefits and operational simplicity.

Innovation Solution

A distribution method and unit that rapidly switch network entities by rewriting Media Access Control (MAC) addresses to select available network entities, enabling load distribution and balancing, and ensuring seamless PDU session migration to idle UPFs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If N:M redundancy model is deployed for UPFs, then cost benefits and operational simplicity are improved, but failover time increases and service disruption occurs

Engineering Contradiction:

Improveoperational simplicityVSAvoidfailover time

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The system performs preliminary actions by pre-establishing backup UPF connections and maintaining ready-to-failover session states. The SMF proactively monitors UPF health and pre-configures failover paths, so when a failure occurs, the switch to backup UPF is immediate rather than requiring lengthy discovery and setup procedures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements continuous feedback mechanisms where the SMF monitors UPF health status in real-time and receives notifications about UPF failures. This feedback loop enables the SMF to detect failures immediately and trigger automated failover procedures, reducing the time from failure detection to service restoration.

Inventive Principle:

Principle #23Feedback

2Quantity of substance

If N:M redundancy model is deployed for UPFs, then cost benefits are improved, but service disruption occurs

Engineering Contradiction:

Improvecost benefitsVSAvoidservice availability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The system performs preliminary actions by pre-establishing backup UPF connections and maintaining ready-to-failover session states. The SMF proactively monitors UPF health and pre-configures failover paths, so when a failure occurs, the switch to backup UPF is immediate rather than requiring lengthy discovery and setup procedures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements dynamic failover capabilities where the SMF can rapidly switch between active and standby UPFs based on real-time health monitoring. This dynamic response allows the system to maintain service availability by adapting to failures immediately, while the N:M model maintains cost efficiency by not requiring full 1:1 redundancy for all scenarios.

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If SMF uses existing criteria for UPF selection, then UPF selection is simple, but load balancing is inadequate and PDU session migration cannot occur

Engineering Contradiction:

ImproveUPF selection simplicityVSAvoidload balancing efficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The system implements continuous feedback mechanisms where the SMF monitors UPF health status in real-time and receives notifications about UPF failures. This feedback loop enables the SMF to detect failures immediately and trigger automated failover procedures, reducing the time from failure detection to service restoration.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system implements dynamic failover capabilities where the SMF can rapidly switch between active and standby UPFs based on real-time health monitoring. This dynamic response allows the system to maintain service availability by adapting to failures immediately, while the N:M model maintains cost efficiency by not requiring full 1:1 redundancy for all scenarios.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12543112B2Distribution method and distribution unit thereof

Publication Date: 2026.02.03 WISTRON CORP

AI summary

A distribution method and a distribution unit thereof are provided. The distribution unit for the distribution method is coupled to a network entity cluster. In the distribution method, a first packet is received, and a first network entity is selected from a plurality of network entities of the network entity cluster. A target MAC address of the first packet is rewritten to a MAC address of the first network entity, and the first packet to the first network entity is transmitted. With the distribution method, PDU session migration from a busy or failed network entity to an idle one can be within few seconds to avoid service disruption.