IMS Network Switching During Ringing-State Call Setup

Solution Overview

Problem

Mobile terminals lose connections during the ringing state when switching communication networks, leading to reduced call connection rates and user inconvenience.

Innovation Solution

A method and device that detect whether a mobile terminal is in a ringing state and, if so, check if it transitions to a connecting state within a predetermined time period before performing an IMS registration to switch to a second communication network, ensuring the connection is established before the switch occurs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If network switching is performed during the ringing state, then network adaptability is improved, but call connection reliability deteriorates

Engineering Contradiction:

Improvenetwork switching capabilityVSAvoidcall connection reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary detection of the terminal state before executing network switching. By detecting whether the terminal is in ringing state or connected state beforehand, the system prevents switching during critical call establishment phases, thus maintaining call connection reliability while still allowing network switching when safe

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism that continuously monitors terminal state and call establishment progress. Based on real-time feedback about whether the call is successfully establishing, the system dynamically adjusts whether to permit network switching, resolving the contradiction between network adaptability and call reliability

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If network switching is performed during the ringing state, then network flexibility is improved, but call connection rate deteriorates

Engineering Contradiction:

Improvenetwork flexibilityVSAvoidcall connection rate

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The system performs preliminary detection of the terminal state before executing network switching. By detecting whether the terminal is in ringing state or connected state beforehand, the system prevents switching during critical call establishment phases, thus maintaining call connection reliability while still allowing network switching when safe

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements a feedback mechanism that continuously monitors terminal state and call establishment progress. Based on real-time feedback about whether the call is successfully establishing, the system dynamically adjusts whether to permit network switching, resolving the contradiction between network adaptability and call reliability

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12483938B2Call network switching method and device, and memory

Publication Date: 2025.11.25 HUIZHOU TCL MOBILE COMM CO LTD

AI summary

Embodiments of the present disclosure are directed to a switching method and a switching device. When a mobile terminal needs to be switched from a first communication network to a second communication network, detecting whether the mobile terminal is in a ringing state. When the mobile terminal is in the ringing state, detecting whether the mobile terminal is switched from the ringing state into a connecting state within a predetermined time period. When the mobile terminal is switched from the ringing state into the connecting state within the predetermined time period, performing an IMS registration through the second communication network to connect the mobile terminal to the second communication network.