IP Multimedia Subsystem (IMS) aspects of architecture for Home Node B (HNB); Stage 2
This Technical Report describes an IMS capable HNB SubSystem (the HNB and the HNB Gateway) as an optional capability of HNB that allows e.g. an operator to offload CS traffic to the IMS. The HNB and HNB Gateway are described in TR 23.830 [5], and the capabilities of these network elements are assumed by this TR.
To achieve this and to satisfy the related requirements and use cases captured in TS 22.220 [2], the objective is to investigate the following:
• an architecture to enable IMS capable HNB Subsystem to use the IMS for CS terminals using a corresponding equivalent IMS services (voice service in IMS Multimedia Telephony);
• the impacts of the IMS capable HNB Subsystem to idle mode mobility for all supported UE types (e.g. IMS registration/de-registration);
• service continuity at least in the direction from IMS capable HNB Subsystem to macro network;
• support for pre-Rel‑9 CS and IMS UEs when using IMS capable HNB Subsystem.
The TR will analyze solutions for the related architectural issues and capture the conclusions.