IMS Core Network VoLTE Setup Fallback to CSFB
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The current VoLTE service in LTE networks does not fully support various supplementary services and experiences low call completion rates due to issues like unsupported supplementary services, lack of VoLTE service activation in roaming areas, and voice bearer setup failures, leading to poor user experience.
Innovation Solution
The IMS core network device receives a request for setting up a VoLTE service and triggers a circuit switched fallback (CSFB) service when VoLTE cannot be established, determining unavailability through checks for supplementary services, VoLTE service activation, and voice bearer setup failures, ensuring the CSFB service is triggered only after the UE has registered with the circuit switched domain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the network reattempts to set up VoLTE service when setup fails, then more call attempts are made, but the call completion rate decreases and user experience deteriorates
Solution Approach 1:
The network performs preliminary checks before attempting VoLTE service setup, including verifying supplementary service availability, VoLTE activation status in the current network, and bearer setup feasibility. By conducting these preparations in advance and identifying unsuitable networks beforehand, the system avoids futile reattempts and directly falls back to CSFB when VoLTE cannot be established, thereby improving call completion rate and service reliability
Solution Approach 2:
The system implements feedback mechanisms where the network device monitors VoLTE setup status and supplementary service availability. When VoLTE setup fails or supplementary services are unavailable, the network provides feedback to trigger CSFB service instead of continuous reattempts. This feedback loop enables dynamic adaptation between VoLTE and CSFB based on real-time network conditions, optimizing call completion and user experience
2Adaptability or versatility
If VoLTE service is not fully activated in a network, then network deployment is simplified, but users experiencing poor call quality when roaming to areas without VoLTE activation
Solution Approach 1:
The network device is designed to handle multiple service modes universally - it can successfully establish both VoLTE services when available and CSFB services when VoLTE is unavailable. By making the service selection mechanism universal and adaptable to different network states, the system ensures continuous service availability regardless of whether the current network supports VoLTE, thereby improving both service availability and call quality reliability for roaming users
3Reliability
If the network checks supplementary service availability before VoLTE setup, then service reliability improves, but the setup process complexity increases
Solution Approach 1:
The network device performs preliminary checks for supplementary service availability, VoLTE activation status, and bearer setup feasibility before initiating the actual VoLTE service setup process. By conducting these validation actions in advance and organizing them in a structured sequence, the system improves service reliability through comprehensive pre-verification while managing complexity through systematic preparation rather than adding unnecessary checks during the setup process
Data Source
AI summary
The present disclosure relates to example service processing methods and devices. In one example method, a request message for setting up a Voice over Long Term Evolution (VoLTE) service for a user equipment (UE) in a packet switched (PS) domain is received by an Internet Protocol multimedia subsystem (IMS) core network device. The IMS core network device triggers a circuit switched fallback (CSFB) service of the UE after determining that the VoLTE service cannot be set up in the PS domain.