Dynamic Call Setup Selection Based on Channel Quality
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Solution Overview
Problem
In communication systems that support multiple air interface protocols, the existing enhanced circuit switched fallback (eCSFB) method for transitioning between LTE and CDMA networks can fail or be inefficient due to poor communication quality, leading to failed call setups when attempting to provide necessary information for call setup procedures.
Innovation Solution
A network node assesses the communication quality of the channel used to serve a wireless device and selects an appropriate call setup procedure from multiple alternatives, such as releasing the device from the LTE network, providing a carrier, or both a carrier and traffic channel, based on the communication quality thresholds to ensure successful and efficient eCSFB call setup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the network provides detailed call setup information (carrier and traffic channel) to the WCD over LTE, then the call setup efficiency is improved, but the reliability deteriorates when channel quality is poor
Solution Approach 1:
The network dynamically changes the call setup procedure parameters based on channel quality indicators (CQI). When CQI is high, the network provides detailed information (carrier and traffic channel). When CQI is low, the network provides only partial information (carrier only) to ensure reliable transmission. This adaptive parameter adjustment resolves the contradiction between efficiency and reliability.
Solution Approach 2:
The system transitions from a static call setup procedure to a dynamic one that adapts to changing channel conditions. The network monitors CQI in real-time and adjusts the information provision strategy accordingly, making the call setup process flexible and responsive to environmental changes, thereby balancing efficiency and reliability.
2Reliability
If the network uses a simplified call setup procedure with less information provision, then the reliability is improved under poor channel conditions, but the call setup efficiency deteriorates
Solution Approach 1:
The network adjusts the information provision parameters based on CQI thresholds. When CQI exceeds a first threshold, full information is provided for efficient setup. When CQI is between thresholds, partial information is provided for reliable setup. This dynamic parameter adjustment resolves the contradiction between reliability and efficiency.
Solution Approach 2:
The call setup procedure becomes dynamic, adapting its information provision level to current channel conditions. This allows the system to optimize for reliability when needed while maintaining efficiency when possible, resolving the trade-off between these two objectives.
3Productivity
If the network always uses the most detailed call setup procedure, then the call setup efficiency is maximized, but the adaptability to different channel conditions deteriorates
Solution Approach 1:
The system implements multiple call setup procedures with different information provision levels, allowing it to adapt to various channel conditions. The network selects the appropriate procedure based on CQI, making the system versatile and responsive to environmental variations while maintaining efficiency when conditions permit.
Solution Approach 2:
The network changes the call setup procedure parameters (information provision level) based on CQI measurements. This allows the system to adapt its behavior to match channel conditions, resolving the contradiction between maximizing efficiency and maintaining adaptability.
4Adaptability or versatility
If the network provides multiple call setup procedure options, then the adaptability to different channel conditions is improved, but the device complexity increases
Solution Approach 1:
The network automatically selects and executes the appropriate call setup procedure based on CQI measurements, without requiring complex decision-making at the WCD side. This shifts the complexity to the network side which has better measurement capabilities, allowing the WCD to remain relatively simple while the system maintains high adaptability.
Solution Approach 2:
The system uses CQI feedback from the WCD to the network to automatically determine the appropriate call setup procedure. This feedback mechanism enables the network to adapt to channel conditions without increasing WCD complexity, as the decision logic resides in the network side that receives the CQI measurements.
Data Source
AI summary
A method and system for dynamically selecting call setup procedure based on channel quality. While a wireless communication device (WCD) is being served by a first radio access network (RAN), a network node receives an indication of a communication quality of the at least one channel used by the first RAN to serve the given WCD. Then, the network node selects a call setup procedure for establishing a call to be served by a second RAN based on the received indication of the communication quality of the at least one channel, where the selected call setup procedure comprises the given WCD transitioning to be served with the call by the second RAN. Next, the network node signals to invoke setup of the call using the selected call setup procedure.