Multi-Access PDU Session Traffic Distribution via ATSSS

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Solution Overview

Problem

Existing 5G network technologies are unable to support the access traffic steering, switching, and splitting (ATSSS) function, as they only establish single access PDU sessions for one access network, limiting the ability to transmit user traffic through multiple access networks.

Innovation Solution

A method for modifying packet data unit (PDU) sessions to enable multi-access PDU sessions by receiving and transmitting ATSSS preference messages between user equipment (UE), access and mobility management function (AMF), session management function (SMF), and access networks, allowing for traffic distribution across multiple access networks through the establishment of an N4 rule and subsequent message transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single access PDU session is established for one access network, then the session management is simple and reliable, but the user traffic cannot be transmitted through multiple access networks, limiting service capability

Engineering Contradiction:

Improvemulti-access traffic transmission capabilityVSAvoidsession management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the session management into two independent parts: MA PDU session management (handled by AMF) and ATSSS rule management (handled by SMF). This segmentation allows multi-access session establishment while keeping each management function relatively simple and independent.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces the SMF as an intermediary between the AMF and UPF to manage ATSSS rules. The SMF receives ATSSS preferences from the UE via the AMF, determines appropriate ATSSS rules, and configures the UPF accordingly, thereby enabling complex multi-access traffic management without increasing the complexity of the AMF or UPF.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If ATSSS rules are configured to distribute traffic across multiple access networks, then service capability is enhanced, but the signaling overhead and message transmission complexity increase

Engineering Contradiction:

ImproveATSSS function supportVSAvoidsignaling overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent uses the existing N1 and N2 signaling interfaces for their dual purposes: the N1 interface carries both user data and ATSSS preference information, while the N2 interface carries both session management messages and ATSSS rule configuration messages. This multi-functionality reduces the need for additional dedicated signaling interfaces.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the ATSSS preference indication with the existing PDU session modification request message, and combines the ATSSS rule configuration with the existing N2 session management messages. This merging approach allows ATSSS functionality to be added without creating separate signaling procedures.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If the UE initiates PDU session modification to change ATSSS rules, then user control over traffic distribution is improved, but the session modification procedure becomes more complex

Engineering Contradiction:

Improveuser control capabilityVSAvoidsession modification procedure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent allows the UE to indicate ATSSS preferences in advance during the PDU session modification procedure. The UE can specify its desired traffic distribution preferences before the network processes the modification, enabling the network to pre-determine appropriate ATSSS rules based on user intent and network conditions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the network determines ATSSS rules based on UE preferences and network conditions, then configures these rules and informs the UE. The UE can subsequently modify its preferences based on the configured rules and network performance, creating a closed-loop control system that balances user control with network management.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11178717B2Traffic distribution method through multi-access network in a network and network entity performing the same

Publication Date: 2021.11.16 ELECTRONICS & TELECOMM RES INST

AI summary

A traffic distribution method through a multi-access network in a network and a network entity performing the same are disclosed. An access and mobility management function (AMF) may receive a PDU session modification request message including an ATSSS (access traffic steering, switching, and splitting) preference, which is a preference for an ATSSS rule, from an user equipment (UE) when a multi-access PDU session (MA PDU session) is established and the UE desires to change the ATSSS rule corresponding to the established MA PDU session. The AMF may transmit a first message including the ATSSS preference to a session management function (SMF).