IMS Control Entity for Reverse SRVCC Media Handover
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Solution Overview
Problem
Current methods for implementing reverse Single Radio Voice Call Continuity (rSRVCC) lack a clear solution for initiating the media connection establishment process between a terminal and the far end during handover from the Circuit Switch (CS) domain to the Packet Switch (PS) domain.
Innovation Solution
A method and system where the Mobile Switch Center (MSC) sends a transfer request to the Control Function Entity (ICFE) of the IP Multimedia Core Network Subsystem, which initiates a media connection establishment flow between the terminal and the far end, ensuring seamless call continuity by updating media resources and handling handover requests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the handover process from CS domain to PS domain is implemented, then call continuity is improved, but the media connection establishment process becomes unclear and complex
Solution Approach 1:
The patent introduces an IMS control function entity as an intermediary between the CS domain and PS domain. This entity receives handover requests from the MSC, determines the handover type, and initiates media connection establishment processes, thereby clarifying the previously undefined media connection establishment process while ensuring call continuity during domain transitions
2Adaptability or versatility
If reverse SRVCC is implemented to support multiple access modes, then service versatility is improved, but the control mechanism becomes insufficient
Solution Approach 1:
The patent enhances the IMS control function entity to perform multiple functions: it not only handles media connection establishment but also determines handover types (intra-PLMN or inter-PLMN), interacts with both MSC and terminal equipment, and manages different handover scenarios. This multi-functional design provides comprehensive control mechanisms while supporting various access modes including CS domain, PS domain, and non-3GPP access
Data Source
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AI summary
A method and system for implementing reverse Single Radio Voice Call Continuity (rSRVCC) are provided in the present invention. The method includes: after receiving a handover request from a Circuit Switch (CS) domain, a current Mobile Switch Center (MSC) sending a transfer request regarding a terminal subscriber or a session in which the terminal subscriber participates to an IP Multimedia Core Network Subsystem (IMS) Control Function Entity (ICFE); and after receiving the transfer request, the ICFE initiating a media connection establishment flow between the terminal and a far end. The technical solution of the present invention ensures rSRVCC when a terminal hands over from a CS domain to a PS domain.