Session Splitting for IMS Handover Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current solutions for service continuity in communication networks, particularly during transitions from WLAN to UTRAN coverage, often result in discontinuation of either voice or other media during IMS PS-to-PS handovers, highlighting the need for effective handling of IMS PS-to-PS handovers, Voice Call Continuity, and media splitting.
Innovation Solution
The method involves sending parallel transfer requests for the packet switched and circuit switched parts of a communication session, with indications for session splitting, and an application server is informed to wait for responses to these requests to ensure seamless transfer of both voice and media parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a UE transfers an ongoing SIP dialog from WLAN to UTRAN GPRS during IMS PS-to-PS handover, then service continuity is improved, but voice and other media may be discontinued during the transfer
Solution Approach 1:
The communication session is segmented into a circuit switched part (voice) and a packet switched part (other media). This allows independent handling and transfer of each part through appropriate networks, enabling seamless handover where voice can continue via CS domain while other media transfers via IMS packet switched domain, thus maintaining service continuity without interruption
Solution Approach 2:
An application server acts as an intermediary to coordinate the split transfer of voice and other media. The server receives transfer requests for both parts, manages the splitting indication, and ensures proper routing and continuity of the communication session during the handover process from WLAN to UTRAN
2Reliability
If the communication session is split into circuit switched and packet switched parts, then voice call continuity is improved, but device complexity increases
Solution Approach 1:
The application server serves as a mediator that handles the complexity of session splitting and coordination. It receives indications and transfer requests for both CS and PS parts, manages the splitting logic, and coordinates the handover process, thereby offloading complexity from the UE and network elements while ensuring voice call continuity
Solution Approach 2:
The application server performs multiple functions including receiving transfer requests, managing session splitting, coordinating handover procedures, and maintaining communication session continuity. This multi-functional approach consolidates complex operations into a single entity, reducing overall system complexity while improving voice call continuity
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
Disclosed is a method including having an ongoing communication session via a packet switched network, transferring said communication session from the packet switched network to a second network providing both packet and circuit switched access, and informing an application server maintaining said ongoing communication session that the communication session is to be split into a packet switched part and a circuit switched part. Also disclosed is a method in an application server, including receiving, from a first communication device, an indication that a communication session between the first communication device and a second communication device is to be split into a packet switched part and a circuit switched part, waiting for to receive transfer requests of both the packet switched partand the circuit switched part, and informing the second communication device of the split.