Methods, systems and computer program products for integrating roaming control in a signaling message routing node

1. A method for providing roaming control, comprising:

at a signaling message routing node separate from a home subscriber server (HSS), wherein the signaling message routing node comprises an IP multimedia subsystem (IMS) serving call session control function (S-CSCF):

(a) receiving a signaling message at the signaling message routing node in a network of a home service provider of a mobile subscriber, the signaling message being generated in response to the mobile subscriber registering in a foreign carrier's network;

(b) determining whether the mobile subscriber is allowed, by the home service provider, to roam in the foreign carrier's network;

(c) in response to determining that the mobile subscriber is not allowed to roam in the foreign carrier's network, generating and sending a response to the signaling message indicating that the mobile subscriber is not allowed to roam in the foreign carrier's network, wherein generating and sending a response to the signaling message is performed instead of sending the signaling message to the HSS, wherein steps (a)-(c) are performed at the signaling message routing node separate from the HSS; and

(d) in response to determining that the mobile subscriber is allowed to roam in the foreign carrier's network, sending the signaling message to the HSS.

2. The method of claim 1 wherein receiving a signaling message includes receiving one of a MAP update_location message, a MAP_update_GPRS_location message, an ANSI-41 REGNOT message, session initiation protocol (SIP) register message, and a SIP invite message.

3. The method of claim 1 comprising determining whether the signaling message is destined for a home location function in the network of the home service provider as a condition to performing steps (b) and (c).

4. The method of claim 1 wherein determining whether the mobile subscriber is allowed to roam in the foreign carrier's network includes accessing a PLMN roaming partner table located in the signaling message routing node to determine whether the foreign carrier is an allowed roaming partner of a home service provider of the mobile subscriber.

5. The method of claim 4 wherein accessing a PLMN roaming partner table includes performing a lookup in the table using an SCCP calling party address in the signaling message.

6. The method of claim 1 comprising, in response to determining that the mobile subscriber is allowed to roam in the foreign carrier's network, forwarding the signaling message to the mobile subscriber's home location function.

7. A system for providing roaming control in a signaling message routing node, the system comprising:

a signaling message routing node separate from a home subscriber server (HSS), wherein the signaling message routing node comprises a serving call session control function (S-CSCF), the signaling message routing node including:

(a) a communication module for sending and receiving signaling messages in a network, the communication module being adapted to receive a signaling message at the signaling message routing node in a network of a home service provider of a mobile subscriber, the signaling message being generated in response to a mobile subscriber registering in a foreign carrier's network; and

(b) a roaming control module for receiving the signaling message from the interface module, and for:

(i) determining whether the mobile subscriber is allowed, by the home service provider, to roam in the foreign carrier's network;

(ii) in response to determining that the mobile subscriber is not allowed to roam in the foreign carrier's network, generating and sending a response to the signaling message indicating that the mobile subscriber is not allowed to roam in the foreign carrier's network, wherein generating and sending a response to the signaling message is performed instead of sending the signaling message to the HSS; and

(iii) in response to determining that the mobile subscriber is allowed to roam in the foreign carrier's network, sending the signaling message to the HSS.

8. The system of claim 7 wherein the signaling message comprises one of a MAP update_location message, a MAP_update_GPRS_location message, an ANSI-41 REGNOT message, session initiation protocol (SIP) register message, and a SIP invite message.

9. The system of claim 7 wherein the roaming control module is adapted to determine whether the signaling message is destined for a home location function in the network of the home service provider.

10. The system of claim 7 wherein the roaming control module is adapted to access a PLMN roaming partner table to determine whether the mobile subscriber is allowed to roam in the foreign carrier's network.

11. The system of claim 10 wherein the roaming control module is adapted to access the PLMN roaming partner control table using an SCCP calling party in the signaling message.

12. The signaling message routing node of claim 7 wherein the roaming control module is adapted to, in response to determining that mobile subscriber is allowed to roam in the foreign carrier's network, forward the signaling message to the mobile subscriber's home location function.