Enhanced IMS services restriction and selection control for mobile devices roaming in foreign networks

A non-transitory computer-readable medium storing instructions that, when executed by a processor in an Internet Protocol Multimedia Subsystem (IMS) network, cause the IMS network to execute a method to register a mobile device for IMS services while the mobile device is roaming in a visited telecommunications network, the method comprising:

• receiving from a mobile device a request for multiple IMS services, the mobile device being located in a visited telecommunications network, the request including a network identifier corresponding to the visited telecommunications network and an access identifier corresponding to the radio access technology associated with the mobile device;
• querying a policy table to determine whether each requested IMS service is allowed, wherein the querying comprises analyzing the policy table to identify each of the multiple requested IMS services that are whitelisted for the associated visited telecommunications network and radio access type,
• wherein querying the policy table comprises transmitting a query to an external system and receiving a response from the external system, the external system being located outside of the IMS network, the query including the network identifier corresponding to the visited telecommunications network and the access identifier corresponding to the radio access technology associated with the mobile device, the response including a list of one or more requested IMS services that are whitelisted for the associated visited telecommunications network and radio access type;
• in response to determining that one or more requested IMS services are whitelisted for the associated visited telecommunications network and radio access type, registering the mobile device with each of the whitelisted IMS services.