VoWiFi Call Handling with AP Switch Control

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Solution Overview

Problem

Frequent switches between WiFi access points (APs) negatively impact voice communication quality and call stability in VoWiFi networks, leading to potential call drops and poor voice communication quality.

Innovation Solution

Implementing strategies to manage and control switches between multiple WiFi APs during communication and idle states, including forbidding AP switches during active calls and switching to cellular networks when WiFi connectivity is lost, while optimizing AP selection based on network connection states and security protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the mobile terminal frequently switches between WiFi access points to maintain network coverage, then the network coverage availability is improved, but the voice communication quality and call stability deteriorate

Engineering Contradiction:
Improvenetwork coverage availabilityVSAvoidvoice communication quality
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The system performs preliminary actions by detecting the communication state before switching occurs. When a voice call is detected, the system proactively configures the WiFi switch to remain at the current access point and disables automatic switching, preventing call drops before they can occur. This preliminary detection and configuration ensures voice communication stability is maintained.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the WiFi switching behavior based on the detected communication state. During voice calls, the switch is configured to remain static at the current access point. During non-voice periods, the switch returns to normal dynamic operation, allowing it to roam between access points for optimal coverage. This dynamic adaptation resolves the contradiction between coverage availability and call stability.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the mobile terminal switches between multiple WiFi access points to maintain connectivity, then the network connectivity is improved, but the call stability deteriorates due to uncertain APs causing call drops

Engineering Contradiction:
Improvenetwork connectivityVSAvoidcall stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system applies preliminary anti-action by detecting voice call states in advance and preemptively configuring the WiFi switch to remain at the current access point, thereby preventing call drops that would otherwise occur during AP switching. This counter-measure is activated before the harmful switching action can occur during critical voice communication periods.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system continuously monitors the communication state through feedback mechanisms, detecting whether voice calls are in progress. Based on this feedback, it dynamically adjusts the WiFi switching behavior - disabling switches during calls and enabling them during non-voice periods. This closed-loop feedback ensures call stability while maintaining network adaptability.

Inventive Principle:
Principle #23Feedback

3Reliability

If the mobile terminal remains at the current WiFi access point during voice calls, then the voice communication quality is improved, but the network coverage adaptability deteriorates

Engineering Contradiction:
Improvevoice communication qualityVSAvoidnetwork coverage adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts the WiFi switching behavior based on communication state feedback. During voice calls, switching is disabled to ensure quality. During non-voice periods, switching is re-enabled to maintain coverage adaptability. This dynamic state-dependent behavior resolves the contradiction by applying different strategies at different times.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs periodic state checking and strategy switching - continuously monitoring communication state and alternating between two operational modes: call-protection mode (no switching) during voice calls and normal-roaming mode (switching enabled) during non-voice periods. This periodic alternation maintains both voice quality and coverage adaptability at appropriate times.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3585099B1Vowifi call processing method of mobile terminal and mobile terminal
Publication Date: 2023.08.23 TCL COMM (NINGBO) CO LTD
  • EP3585099B1 patent drawingFigure 1~2

AI summary

An VoWiFi call processing method of a mobile terminal includes: pre-performing, using a mobile terminal, an VoWiFi registration, controlling and managing, in a VoWiFi call state and idle state, switches among a plurality of WiFi APs; when the mobile terminal is in the call state in a VoWiFi network, forbidding the mobile terminal to initiate an inter-WiFi AP switch, and when the mobile terminal is unable to connect to the WiFi network, controlling the mobile terminal to switch to a cellular network to call; and when the mobile terminal is in the idle state in the VoWiFi network, controlling the mobile terminal to initiate an AP switch and checking an AP connection state, when an AP can establish a normal connection to a network, staying at the AP, and when the AP cannot establish a connection to the network, returning to an original AP and continuing to search.