Video Telephony Call Setup via 3G Network Prioritization
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Solution Overview
Problem
In video telephony over LTE networks, call setup failures and service quality degradation occur when user equipment (UE) is switched to networks that do not support the required data rate for video telephony, such as 2G networks, leading to inadequate data transmission resources.
Innovation Solution
A method and apparatus that prioritize switching the UE to a 3G network for video telephony by transmitting specific call setup request messages, measurement reports, and CSFB execution commands to ensure access to a 3G cell with sufficient data resources, thereby preventing call setup failures and quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the UE is switched to a 2G network for video telephony, then the call setup process is simplified, but the data transmission resources become insufficient leading to service quality degradation
Solution Approach 1:
The patent changes the network selection parameter from default 2G to prioritized 3G when video telephony is detected. The MME modifies the CSFB target network type based on the service type indicator in the service request message, ensuring the UE connects to a network with sufficient data transmission resources for video services.
2Reliability
If the UE is switched to a 3G network for video telephony, then the data transmission resources are sufficient, but the switching process becomes more complex
Solution Approach 1:
The patent performs preliminary detection of video telephony service type before the network switching occurs. The MME identifies the video service requirement from the service request message and pre-determines the appropriate target network (3G) before executing the CSFB switching, thereby streamlining the overall process despite the higher network selection requirement.
Solution Approach 2:
The MME acts as an intermediary between the UE and the target network during CSFB. It receives the service request with video telephony indication, determines the appropriate 3G target network, and guides the UE switching process, thereby managing the complexity of 3G network selection and switching.
3Reliability
If the UE remains on LTE network for video telephony, then the data rate requirements are met, but CSFB switching is still triggered causing call setup failures
Solution Approach 1:
The patent applies preliminary anti-action by detecting the video telephony service type before CSFB switching is executed. The MME prevents the default switching to 2G network by identifying the video service requirement in advance and redirecting the switching process to an appropriate 3G network, thereby avoiding call setup failures that would occur with inadequate 2G resources.
Data Source
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AI summary
A communication method and apparatus is provided for enhancing video telephony service quality by protecting against call setup failure or service quality degradation caused due to switching of the User Equipment (UE) to a network which does not fulfill the data rate required for video telephony in the video call setup process. The communication method of a terminal in a mobile communication system according to the present disclosure includes transmitting a video telephony call setup request message, receiving a switching command for Circuit Switched Fall Back (CSFB), and setting, if the switching command includes a target cell type set to the 2nd Generation (2G) cell and if a 3rd Generation (3G) cell to which the terminal can access exists, up the video telephony call by switching a connection to the 3G cell.