Abstract: There are provided measures for enabling/realizing service continuity in a centralized service network system. Such measures exemplarily comprise detecting a deregistration request for deregistering a terminal with respect to a first switching entity from a registration in which the first switching entity is registered for the terminal as a contact point for centralized services, starting a waiting timer for waiting for a registration request for registering the terminal with respect to a second switching entity upon detection of said deregistration request, and re-registering the terminal in the registration such that the second switching entity is registered for the terminal as a contact point for centralized services upon detection of the registration request for registering the terminal with respect to the second switching entity before expiry of the waiting timer.

Abstract: There are provided measures for enabling/realizing service continuity in a centralized service network system. Such measures exemplarily comprise detecting a deregistration request for deregistering a terminal with respect to a first switching entity from a registration in which the first switching entity is registered for the terminal as a contact point for centralized services, starting a waiting timer for waiting for a registration request for registering the terminal with respect to a second switching entity upon detection of said deregistration request, and re-registering the terminal in the registration such that the second switching entity is registered for the terminal as a contact point for centralized services upon detection of the registration request for registering the terminal with respect to the second switching entity before expiry of the waiting timer.

Abstract: The invention relates to an apparatus, method and a computer program product for establishing a request for a session by an application server, determining by an emergency related local service function that the session includes an emergency session, wherein the emergency related local service function is co-located at the application server, and, transmitting the request for the session to an emergency call state control function of the internet protocol multimedia subsystem based on the determination.

Abstract: The invention relates to an apparatus, method and a computer program product for establishing a request for a session by an application server, determining by an emergency related local service function that the session includes an emergency session, wherein the emergency related local service function is co-located at the application server, and, transmitting the request for the session to an emergency call state control function of the internet protocol multimedia subsystem based on the determination.

Abstract: A method of allocating one of a plurality of call state control functions to a subscriber, the method comprising: sending registration requests to the plurality of call state control functions; storing information regarding the availability of the call state control functions in response to unsuccessful registration requests; and determining a call state control function for the subscriber in dependence on said stored information.