5G Terminal AMF Registration for Network Slice Selection

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Solution Overview

Problem

In 5G communications networks, terminals often face challenges in determining the correct network slice selection assistance information (S-NSSAI) when roaming to a visited public land mobile network (VPLMN) without a pre-configured network slice selection policy, leading to incomplete PDU session establishment and communication failures.

Innovation Solution

A registration method and session establishment method where terminals send specific messages to the Access and Mobility Management Function (AMF) entity to request and obtain the network slice selection policy, ensuring accurate determination of S-NSSAI in the VPLMN or home PLMN, facilitating successful PDU session establishment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the terminal uses pre-configured NSSP for network slice selection, then the terminal can quickly determine S-NSSAI in the home network, but the terminal cannot determine S-NSSAI when roaming in a VPLMN without pre-configured NSSP

Engineering Contradiction:

ImprovePDU session establishment speedVSAvoidNetwork slice selection capability in VPLMN

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The terminal performs preliminary actions by sending a registration request message including a first parameter indicating whether NSSP is configured before actually needing to establish a PDU session. This advance notification allows the AMF entity to prepare and provide the necessary NSSP information in the registration accept message, ensuring the terminal has the required network slice selection capability before roaming operations begin.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The AMF entity acts as an intermediary between the terminal and the network slice selection policy information. When the terminal indicates it needs NSSP during registration, the AMF entity retrieves and provides the appropriate NSSP from network resources, mediating the information flow to ensure the terminal receives accurate network slice selection policies for the current VPLMN or HPLMN.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the terminal requests NSSP information during registration, then the terminal can accurately determine S-NSSAI in VPLMN, but additional signaling messages are required

Engineering Contradiction:

ImproveS-NSSAI determination accuracyVSAvoidRegistration signaling complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the NSSP request and response into the existing registration procedure. The first parameter indicating NSSP configuration status is embedded within the registration request message, and the NSSP information is delivered through the registration accept message. This combining approach avoids creating separate dedicated signaling procedures, thereby limiting the increase in signaling complexity while still achieving reliable S-NSSAI determination.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If the AMF entity provides NSSP in the registration accept message, then the terminal can complete PDU session establishment in VPLMN, but the AMF entity needs to manage additional information

Engineering Contradiction:

ImprovePDU session establishment success rateVSAvoidAMF entity information management complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The AMF entity implements self-service by automatically managing the NSSP information lifecycle. When the terminal indicates it needs NSSP during registration, the AMF entity autonomously retrieves, stores, and provides the appropriate NSSP information without requiring manual configuration or complex external coordination. This self-managing approach simplifies the overall system architecture while ensuring reliable PDU session establishment.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11523465B2Registration method, session establishment method, terminal, and AMF entity

Publication Date: 2022.12.06 HUAWEI TECH CO LTD

AI summary

A registration method, a session establishment method, a terminal, and an access and mobility management function (AMF) entity, where the method includes: sending, by a terminal, a first message to the AMF entity, where the first message includes first information, first network slice selection information, and second network slice selection information, the first information includes information for requesting to establish a protocol data unit (PDU) session, the first network slice selection information is used by the AMF entity to select a first session management function (SMF) entity, and the second network slice selection information is used by the AMF entity to select a second SMF entity; and receiving, by the terminal, a second message from the AMF entity, where the second message includes second information, and the second information includes PDU session establishment accept information.