IP Multimedia Subsystem (IMS) service continuity; Inter-UE transfer enhancements; Stage 2
This technical report intends to develop enhancements to Rel-9 IMS Service Continuity in TS 23.237 [2], specifically in the functional area of Inter-UE Transfer. The main objective is to provide enhancements to mobility of media flows of a session between different UEs (Inter-UE Transfer) with respect to the following aspects:
- Extension of Inter-UE Transfer and Collaborative Session capabilities specified in Rel-09 to multiple UEs belonging to different IMS subscriptions under the same operator.
- Establishment of a Collaborative Session at session setup.
- Support for control of media components of a Collaborative Session by more than one UE simultaneously.
- Transfer of control of a Collaborative Session.
- Controller initiated media modification on a Controllee UE (e.g. video resolution).
- Discovery of ongoing IMS multimedia sessions on different UEs.
- Inter-UE Transfer initiated by the target UE when:
- the target UE belongs to the Collaborative Session but it is not a Controller UE;
- the target UE does not belong to the Collaborative Session and wants to join;
- Inter-UE Transfer is performed without establishing a Collaborative Session.
- Replication of an ongoing multimedia session from one UE on another UE.
- Inter-UE Transfer between UEs connected to the IMS via an IP-CAN and ICS entities that provide interworking with UEs in the CS Domain.
- Execution of MMTEL services for Collaborative Sessions.
This document contains the results of an assessment of alternative architectures to support Inter-UE Transfer enhancements.