International internet protocol multimedia subsystem (IMS) call network authorization

A method of authorizing an IP multimedia system (IMS) call in a foreign country for a wireless communication device that has a wireless communication subscription service with a United States (US) wireless communication service provider, comprising:

• updating an allow list in a first home subscriber server (HSS) database of a plurality of HSS databases maintained by the US wireless communication service provider, wherein the allow list identifies countries in which the US wireless communication service provider allows subscribers to receive international IMS roaming service including a first country that is outside of the US;
• automatically replicating the update of the allow list in the first HSS database to other HSS databases of the plurality of HSS databases maintained by the US wireless communication service provider;
• receiving a request for authorization to originate a first IMS call by an HSS located in the US, wherein the request is received from a first wireless communication device located outside of the US and the request identifies a first country where the first wireless communication device is located;
• determining by the HSS that international IMS roaming service is allowed by the wireless communication service provider in the first country by looking up the first country in an allow list in one of the other HSS databases;
• determining by the HSS that a first wireless communication subscription service associated with the first wireless communication device allows international IMS roaming service;
• and
• sending an authorization to originate the first IMS call by the HSS to the first wireless communication device, whereby the first wireless communication device is enabled to originate the first IMS call in the first country.

A method of authorizing an IP multimedia system (IMS) call in a foreign country for a wireless communication device that has a wireless communication subscription service with a United States (US) wireless communication service provider, comprising:

• updating an allow list in a first home subscriber server (HSS) database maintained by the US wireless communication service provider, wherein the allow list identifies countries in which the US wireless communication service provider allows subscribers to receive international IMS roaming service including a first country that is outside of the US;
• automatically replicating the update of the allow list in the first HSS database to a plurality of other HSS databases maintained by the US wireless communication service provider;
• receiving a request for authorization to originate a first IMS call by an HSS located in the US, wherein the request is received from a first wireless communication device and the request identifies the first country;
• determining by the HSS that international IMS roaming service is allowed by the wireless communication service provider in the first country by looking up the first country in an allow list in a second HSS database, wherein the second HSS database is one of the other HSS databases maintained by the US wireless communication service provider;
• and
• sending an authorization to originate the first IMS call by the HSS to the first wireless communication device, whereby the first wireless communication device is enabled to originate the first IMS call in the first country.