Dual Call Setup for Voice Continuity in Wireless Networks
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Solution Overview
Problem
Current Voice Call Continuity (VCC) and Single Radio VCC (SRVCC) technologies face issues with call service provision during network transitions, leading to connection delays, data loss, and vocoder compatibility problems, necessitating additional interfaces and transcoding in wireless communication systems.
Innovation Solution
A method and apparatus for providing call continuity between Voice over Internet Protocol (VoIP) and Circuit Switched (CS) calls using dual call setups in wireless communication systems, allowing seamless network switching without additional interfaces and minimizing voice interruptions by concurrently operating different vocoders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If VCC or SRVCC technology is used to provide call continuity between new network and established network, then call continuity is improved, but additional interfaces and transcoding are required increasing system complexity
Solution Approach 1:
The patent extracts the call control function from the core network to the access network. The access network controller directly manages call setup, modification, and release between different networks, eliminating the need for complex core network interfaces and transcoding functions while maintaining call continuity.
Solution Approach 2:
The access network controller acts as an intermediary that directly manages calls between different networks. By placing the controller at the access network level, it mediates call operations without requiring additional core network interfaces or transcoding functions.
2Reliability
If handover is carried out in the IMS stage rather than air interface, then network control is improved, but voice data loss occurs degrading voice quality
Solution Approach 1:
The patent performs call setup in advance on both networks before switching. The terminal establishes calls on both the new network and established network beforehand, so when switching occurs, the voice path can be immediately redirected without data loss or interruption.
Solution Approach 2:
The patent maintains continuous call establishment and voice path setup across network transitions. By keeping the call active and voice path established on both networks simultaneously, the useful action of voice transmission continues without interruption during the switch.
3Adaptability or versatility
If different vocoders are used in PS network and CS network, then network independence is improved, but transcoding is required increasing core network load
Solution Approach 1:
The patent extracts the vocoder selection and voice processing function from the core network to the terminal and access network. Each network can use its native vocoder independently, and the terminal handles the voice processing without requiring core network transcoding, thus eliminating the additional load.
Solution Approach 2:
The terminal and access network self-manage voice processing and vocoder selection. Each network independently uses its own vocoder without requiring core network intervention for transcoding, making the system self-sufficient and reducing core network load.
Data Source
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AI summary
An apparatus and a method for providing call continuity in a wireless communication system are provided. The apparatus includes a first communication unit for setting a call with a counterpart terminal in a first network, a second communication unit for setting a call with the counterpart terminal in a second network while the call is set in the first network, and a control unit for terminating the call of the first network after the call setup is completed in the second network.