19.5 Study on centralized ims services uid_380034

Resources: S2,S1

References

Document	Title/Contents
WID(s)
SP-070494	SID on Centralised IMS Service Control
Impacted Specifications
-	-
New Dedicated Specifications/Reports
TR 22.892	Study on IMS Centralized Services (ICS) requirements
TR 23.892	IP Multimedia Subsystem (IMS) centralized services

Supporting Individual Members: Alcatel-Lucent, Nortel, , Telcordia, Ericsson, AT&T, Nokia, , Cingular, Telecom Italia, Siemens, Motorola, Huawei, Samsung, NEC, Newstep, Marvell Semiconductor, Airbiquity, LG Electronics, Rogers Communications, T-Mobile, TeliaSonera.

Communication networks are evolving towards packet based infrastructures, and a need exists to specify service requirements and an architecture that support the provision of IMS based services across a variety of access networks (e.g. wireless and wireline, enterprise and consumer, etc.).

Development of the architecture for Voice Call Continuity (VCC) has identified that supporting domain transfer of active mid-call services by implementing these services in both the CS domain and IMS is not a viable solution in the Rel-7 timeframe. Therefore an architecture is necessary allowing implementation of such services in IMS while also allowing control when the serving access network is in the CS domain. In addition to the VCC scenario, the increased deployment of VoIP capable access technologies encourages further service development on IMS also increasing the importance of being able to access these services via CS domain access, independently of the support of VCC.

The first objective is the delivery of consistent services to the user mainly via IMS centralized services regardless of the attached access type (e.g. CS domain access or Internet Protocol ‑ Connectivity Access Network (IP‑CAN)).

SA1 TR 22.892 describes service experience and proposes service requirements.

SA2 TR 23.892 focuses on how to access IMS-based multimedia telephony services while still allowing innovative services. It includes investigation into call/session establishment via CS domain access and IP-CAN and for calls/sessions transferred across CS domain access and IP-CAN, including the interactions with domain selection. Furthermore it provides consideration for the handling of the multiple media that are enabled by the multimedia telephony communication service. The proposed solution applies to terminals with VCC capabilities and to non-VCC capable terminals. Impact on legacy terminals with the same subscription (e.g. SIM swapping) was studied.

The standardization of an IMS Centralized Services architecture is to be started later based on the results of this study. This can be achieved without completely resolving evolution considerations. A high-level conceptual overview of ICS is provided in the following figure, extracted from TR 22.892.