SRVCC Capability Provisioning for Seamless Voice Handovers
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Solution Overview
Problem
Current mobile communication systems face challenges in maintaining service continuity and quality of service (QoS) when user equipment (UE) moves across different networks, particularly in transferring sessions from packet-switched (PS) domains to legacy circuit-switched (CS) domains, leading to potential voice or video call disruptions due to the inability to determine supported Single Radio Voice Call Continuity (SRVCC) capabilities during initial NAS registration or inter-system changes.
Innovation Solution
A method and system that involve a server-implemented approach to receive and provide registration state information indicating SRVCC capabilities, allowing network nodes to determine and indicate SRVCC support during SIP registration, enabling seamless handovers between different core networks and access networks, including 4G and 5G systems, by using Session Initiation Protocol (SIP) and NAS registration procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If handover techniques are used to transfer calls between networks, then service continuity is preserved, but voice interruption delays occur during the handover process
Solution Approach 1:
The patent applies preliminary action by determining SRVCC capabilities during initial NAS registration or inter-system change events, before handover is actually needed. This advance determination stores capability information that can be quickly retrieved during handover operations, eliminating the need for real-time capability assessment and reducing voice interruption delays while maintaining service continuity
2Productivity
If SRVCC capability determination is performed during initial NAS registration, then handover efficiency is improved, but network complexity increases
Solution Approach 1:
The patent merges the SRVCC capability determination process with existing NAS registration or inter-system change procedures. By combining these functions into already-established signaling flows, the patent improves handover efficiency without adding separate complex determination mechanisms, thus minimizing network complexity while enhancing productivity
3Adaptability or versatility
If separate instances of UE SRVCC capabilities are stored for different accesses, then adaptability is improved, but information management complexity increases
Solution Approach 1:
The patent segments UE SRVCC capability information into separate instances for different accesses (e.g., 5G New Radio access and 4G E-UTRAN access). This segmentation allows the network to selectively apply appropriate SRVCC capabilities based on the current access type, improving adaptability while maintaining organized, manageable information structures through clear separation of access-specific capability data
Data Source
AI summary
A server-implemented method is disclosed. The method includes: receiving a request from an IP Multimedia Subsystem (IMS) network node of an IMS network; and in response to receiving the request, providing NAS registration state information associated with a user equipment (UE) to the IMS network node, the NAS registration state information indicating at least one of fourth-generation (4G) single radio voice call continuity (SRVCC) capability of the UE or fifth-generation (5G) SRVCC capability of the UE that is applicable when using an access network supported by a core network, wherein the server is configured to store separate instances of UE SRVCC capabilities, the separate instances including indications of at least one of 4G UE SRVCC capability or 5G UE SRVCC capability that is applicable when using the access network supported by the core network, and wherein the UE is registered with the IMS network using a session initiation protocol (SIP) via the access network.