23.1983GPPOpen Service Access (OSA)Stage 2TS
The OSA APIs may be used by the Home Environment, by Value Added Service Providers (VASPs) and Home Environment Value Added Service Providers (HE-VASPs).
OSA is optimized to support HE-VASPs as the user subscription information is owned and managed by the Home Environment, i.e. the Home Environment knows which users are subscribed to the service implemented by the OSA application, and if the service is activated or not.
Specific methods are specified in OSA Service Capability Features, permitting:
- An OSA application to request user related event notifications pertaining to any subscribed user for which the service implemented by the application is activated.
- The OSA SCS to report user related event notifications in which it explicitly identifies the user to which the event applies.
- An OSA application to request a function to be applied to all current subscribed users for which the service implemented by the application is activated.
The OSA SCS can report user related events to the OSA application, without the application having explicitly subscribed to the event (events to be reported have been agreed between the Home Environment and the HE-VASP by other means, e.g. in their service level agreement).
This functionality is supported by all relevant Service Capability Features, like call and session control SCFs, user status, and user location.