Roaming management system

1. A method of provisioning a subscriber profile into a subscriber data store of an IP Multimedia System (IMS)-capable telecommunications network, the subscriber profile being for a subscriber which is a visiting subscriber with respect to the IMS-capable telecommunications network and from a home network that does not have Voice over LTE (VoLTE), the subscriber data store being for use in IP Multimedia System (IMS) call processing, the method comprising:

receiving, by a modified Serving Gateway and Packet Data Network Gateway (SGW/PGW), a request to allocate an IMS Access Point Name (APN), wherein the modified SGW/PGW is:

operable to simulate a 2G/3G Mobile Switching Center and Visited Location Register (MSC/VLR) to the home network;

assigned to roaming subscribers from networks that do not have VoLTE; and

configured to notify a Visitor Location Register Application Server (VLR AS) that the visiting subscriber's user equipment (UE) has attached to the IMS-capable telecommunications network;

in response to receiving the request to allocate the IMS APN, triggering, by the modified SGW/PGW, a provisioning of the subscriber profile into the subscriber data store by transmitting a notification to the VLR AS;

in response receiving the notification, transmitting by the VLR AS, a request to provision the subscriber profile into a Home Subscriber Server (HSS) of the IMS-capable telecommunications network; and

triggering, by the VLR AS, a location update in a home location register (HLR) of the home network of the visiting subscriber.

2. The method of claim 1 , wherein the IMS HSS is configured to store subscriber profiles for subscribers which are home subscribers with respect to the IMS-capable telecommunications network.

3. The method of claim 1 , further comprising:

receiving a SIP REGISTER message at an IMS Application Server (AS); and

in response to receiving the SIP REGISTER message, triggering a location update in the Home Location Register (HLR).

4. The method of claim 3 , comprising:

in response to the location update, receiving subscriber data from the HLR;

deriving supplementary services data for the subscriber from the received subscriber data; and

transmitting the supplementary services data to a Telephony Application Server (TAS) for use during call processing.

5. The method of claim 1 , comprising:

installing a set of supplementary services for the subscriber subsequently, during a registration procedure which involves use of the subscriber profile.

6. The method of claim 5 , comprising provisioning the subscriber profile into the Home Subscriber Server (HSS); and

querying the HSS for at least of a part of the provisioned subscriber profile during the registration procedure.

7. The method of claim 1 , comprising:

receiving the request to allocate an IMS APN from a Mobile Management Entity (MIME); and

allocating the IMS APN; and

sending a confirmation message indicative of the allocated IMS APN to the MME.

8. A method of provisioning a subscriber in an IP Multimedia System (IMS) capable telecommunications network, the subscriber being a visiting subscriber with respect to the IMS-capable telecommunications network, the method comprising:

receiving, by a modified Serving Gateway and Packet Data Network Gateway (SGW/PGW), a request to allocate an IMS Access Point Name (APN), wherein the modified SGW/PGW is:

operable to simulate a 2G/3G Mobile Switching Center and Visited Location Register (MSC/VLR) to the visiting subscriber's home network;

assigned to roaming subscribers from networks that do not have VoLTE, and

configured to notify a Visitor Location Register Application Server (VLR AS) that the visiting subscriber's user equipment (UE) has attached to the IMS-capable telecommunications network;

in response to receiving the request to allocate the IMS APN, triggering, by the modified SGW/PGW, an initial provisioning of a subscriber profile for the subscriber; and

installing a set of supplementary services for the subscriber subsequently, during a registration procedure which involves use of the subscriber profile.

9. The method of claim 8 , further comprising provisioning the subscriber profile into a Home Subscriber Server (HSS); and

querying the HSS for at least of a part of the provisioned subscriber profile during the registration procedure.

10. The method of claim 9 , wherein the subscriber is from a home network that does not have Voice over LTE (VoLTE).

11. The method of claim 9 , further comprising:

in response to receiving the request to allocate the IMS APN, transmitting a notification to an IMS Application Server (AS).

12. The method of claim 11 , further comprising, in response receiving the notification, transmitting a request to provision the subscriber profile into the HSS.

13. The method of claim 8 , further comprising:

receiving a SIP REGISTER message at an IMS Application Server (AS); and

in response to receiving the SIP REGISTER message, triggering a location update in a Home Location Register (HLR) in a home telecommunications network of the visiting subscriber; and

installing the set of supplementary services for the subscriber in response to the location update.

14. The method of claim 13 , further comprising:

in response to the location update, receiving subscriber data from the HLR;

deriving supplementary services data for the subscriber from the received subscriber data; and

transmitting the supplementary services data to a Telephony Application Server (TAS) for use during call processing.

15. A non-transitory computer readable medium containing computer-readable instructions for causing a processor to perform operations for provisioning a subscriber profile into a subscriber data store of an IP Multimedia System (IMS) capable telecommunications network, the subscriber profile being for a subscriber which is a visiting subscriber with respect to the IMS-capable telecommunications network, the subscriber data store being for use in IP Multimedia System (IMS) call processing, the operations comprising:

receiving, by a modified Serving Gateway and Packet Data Network Gateway (SGW/PGW), a request to allocate an IMS Access Point Name (APN)), wherein the modified SGW/PGW is:

operable to simulate a 2G/3G Mobile Switching Center and Visited Location Register (MSC/VLR) to the visiting subscriber's home network; and

configured to notify a Visitor Location Register Application Server (VLR AS) that the visiting subscriber's user equipment (UE) has attached to the IMS-capable telecommunications network; and

in response to receiving the request to allocate the IMS APN, triggering, by the modified SGW/PGW, a provisioning of the subscriber profile into the subscriber data store by transmitting a notification to the VLR AS.

16. The non-transitory computer readable medium of claim 15 , wherein the subscriber is from a home network that does not have Voice over LTE (VoLTE).

17. The non-transitory computer readable medium of claim 16 , wherein the modified SGW/PGW is assigned to roaming subscribers from networks that do not have VoLTE.