Terminal Device Network Search for 5G Service Availability

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Solution Overview

Problem

In 5G communications systems, terminal devices cannot actively initiate services when located in non-allowed areas, despite displaying a signal, leading to poor user experience due to the non-access stratum not processing service requests in these areas.

Innovation Solution

A network search method that allows terminal devices to detect and switch to allowed areas by using the service area restriction information, triggering the RRC layer to search for cells within allowed areas and temporarily prohibiting non-allowed areas, enabling communication through alternative radio access technologies when 5G access is restricted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the terminal device displays a 5G signal icon to indicate network availability, then the user perceives that services should be accessible, but the non-access stratum blocks service requests in non-allowed areas, leading to user confusion and poor experience

Engineering Contradiction:
ImproveService availability informationVSAvoidService initiation capability
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The terminal device proactively searches for alternative allowed areas or radio access technologies before the user attempts to initiate a service. When the NAS layer determines the current area is non-allowed, it triggers the RRC layer to search for alternative cells or networks in advance, so that when service initiation is requested, the device can quickly switch to an allowed area rather than blocking the service

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The RRC layer acts as an intermediary between the NAS layer and the physical communication layer. When the NAS layer identifies a non-allowed area, it communicates this restriction to the RRC layer, which then mediates by searching for alternative allowed cells or radio access technologies, bridging the gap between the service request and the physical network availability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the terminal device restricts service initiation in non-allowed areas to comply with network policies, then network security and policy enforcement are improved, but user experience deteriorates due to blocked services despite signal coverage

Engineering Contradiction:
ImproveNetwork policy enforcementVSAvoidService accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The terminal device dynamically adjusts its service initiation capability based on real-time area restrictions. Instead of statically blocking all services in non-allowed areas, the device continuously monitors for alternative allowed areas through RRC layer searches and dynamically switches between allowed and non-allowed areas, maintaining both policy compliance and service accessibility

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The terminal device changes the parameter of service availability by switching between different radio access technologies or cellular networks. When 5G access is restricted in the current area, the device changes parameters by searching for and connecting to alternative 5G cells in allowed areas or switching to other radio access technologies, thereby maintaining service continuity while respecting area restrictions

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the terminal device continuously searches for alternative allowed areas to ensure service availability, then service continuity is improved, but energy consumption increases due to frequent network searches

Engineering Contradiction:
ImproveService initiation success rateVSAvoidEnergy consumption for network searching
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The terminal device performs periodic network searches instead of continuous searching. The RRC layer conducts cell searches at predetermined intervals or triggered by specific events (such as when service initiation is attempted), reducing energy consumption while maintaining the ability to find alternative allowed areas when needed

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The terminal device performs preliminary checks to determine whether a service request should be blocked before attempting network searches. The NAS layer first evaluates whether the current area is non-allowed, and only triggers RRC layer searches when necessary, avoiding unnecessary energy consumption from continuous searching while ensuring service availability when alternatives exist

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3902328B1Network searching method, and terminal device
Publication Date: 2024.07.31 HUAWEI TECH CO LTD
  • EP3902328B1 patent drawingFigure 1
  • EP3902328B1 patent drawingFigure 2
  • EP3902328B1 patent drawingFigure 3

AI summary

This application provides a network search method and a terminal device. The method includes: receiving, by a terminal device, a user operation, where the user operation requests communication with a network device by using a 5G access technology; and when a cell with which the terminal device currently registers is a non-allowed area, searching for a second cell, where the second cell is an allowed area, so that the terminal device communicates with the network device in the second cell by using the 5G access technology. Therefore, when actively initiating a service, the terminal device in the non-allowed area may actively search for a cell that is an allowed area, to communicate with the network device by using the 5G access technology. This can avoid a case in which the terminal device in the non-allowed area cannot communicate with the network device by using the 5G access technology, thereby improving user experience.