Systems and methods for routing SMS messages in a visited network using a proxy

1 . A method, comprising:

during a registration process on a visited public land mobile network (VPLMN) of a user equipment (UE), receiving at the VPLMN a home location register (HLR) profile comprising profile information of the UE from the HLR of a home public land mobile network (HPLMN), wherein the VPLMN is a first type of network and the registration process includes:

receiving, at a visitor subscriber server (VSS) of the VPLMN, a map update location from associated with the UE, and

building a VSS profile for the UE if the VSS profile is not present or updating the VSS profile if the VSS profile was stored on the VSS;

receiving, at the VSS, a short messaging service (SMS) message from the HPLMN intended for a user equipment (UE) when the UE is registered with the VPLMN, wherein the VSS is configured to act as a proxy for a mobile switching center (MSC) of a second type of network;

determining, by the VSS, if the UE supports SMS over internet protocol (IP) or SMS over service gateways (SGS);

if the VSS determines that the UE supports SMS over IP, delivering the SMS message to an IP multimedia subsystem (IMS) of the VPLMN; or

if the VSS determines that the UE does not support SMS over IP, delivering the SMS message to the UE using SMS over SGS, wherein the delivering comprises delivering the SMS message from the VSS to a mobile call operator (MCO), which delivers the SMS message to a mobility management entity (MME) to which the UE is attached, which in turn delivers the message to the UE.

2 . The method of claim 1 , wherein determining, by the VSS, if the UE supports SMS over internet protocol (IP) or SMS over service gateways (SGS) is based at least in part on the profile information, and the profile information comprises information to indicate that the UE supports SMS over IMS.

3 . The method of claim 1 , wherein the registration process further comprises:

receiving, at the MME, an attach request from the UE;

transmitting an SGS location update to the MCO, wherein the MCO is configured to provide services for a mobile switching server of the second type of network; and

transmitting the map update location from the MCO to the VSS.

4 . The method of claim 1 , wherein the map update location comprises an international mobile subscriber identity (IMSI) of the UE.

5 . The method of claim 1 , further comprising transmitting an updated map update location message to the HLR of the HPLMN, wherein the updated map update location message comprises a visitor location register (VLR) address of the VSS, and wherein the VLR address of the VSS is used by a short message service center (SMSC) of the HPLMN to direct the SMS message.

6 . The method of claim 1 , wherein the HLR profile comprises a public number of the UE.

7 . A non-transitory computer-readable media storing computer-executable instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

during a registration process on a visited public land mobile network (VPLMN) of a user equipment (UE), receiving at the VPLMN a home location register (HLR) profile comprising profile information of the UE from the HLR of a home public land mobile network (HPLMN) wherein the VPLMN is a first type of network and the registration process includes:

receiving, at a visitor subscriber server (VSS) of the VPLMN, a map update location from associated with the UE, and

building a VSS profile for the UE if the VSS profile is not present or updating the VSS profile if the VSS profile was stored on the VSS;

receiving, at the VSS, a short messaging service (SMS) message from the HPLMN intended for a user equipment (UE) when the UE is registered with the VPLMN, wherein the VSS is configured to act as a proxy for a mobile switching center (MSC) of a second type of network;

determining, by the VSS, if the UE supports SMS over internet protocol (IP) or SMS over service gateways (SGS);

if the VSS determines that the UE supports SMS over IP, delivering the SMS message to an IP multimedia subsystem (IMS) of the VPLMN; or

if the VSS determines that the UE does not support SMS over IP, delivering the SMS message to the UE using SMS over SGS, wherein the delivering comprises delivering the SMS message from the VSS to a mobile call operator (MCO), which delivers the SMS message to a mobility management entity (MME) to which the UE is attached, which in turn delivers the message to the UE.

8 . The non-transitory computer-readable media of claim 7 , wherein the determining, by the VSS, if the UE supports SMS over internet protocol (IP) or SMS over service gateways (SGS) is based at least in part on the profile information, and the profile information comprises information to indicate that the UE supports SMS over IMS.

9 . The non-transitory computer-readable media of claim 7 , wherein the registration process further comprises:

receiving, at the MME, an attach request from the UE;

transmitting an SGS location update to the MCO, wherein the MCO is configured to provide services for a mobile switching server of the second type of network; and

transmitting the map update location from the MCO to the VSS.

10 . The non-transitory computer-readable media of claim 7 , wherein the map update location comprises an international mobile subscriber identity (IMSI) of the UE.

11 . The non-transitory computer-readable media of claim 7 , further comprising computer-executable instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising transmitting an updated map update location message to the HLR, wherein the updated map update location message comprises a visitor location register (VLR) address of the VSS, and wherein the VLR address of the VSS is used by a short message service center (SMSC) of the HPLMN to direct the SMS message.

12 . The non-transitory computer-readable media of claim 7 , wherein the HLR profile comprises a public number of the UE.

13 . A mobile telecommunications network, comprising:

a visitor subscriber server (VSS) acting as a proxy for a mobile switching center (MSC) used in a 2G/3G network, wherein the VSS is configured to:

update or build a profile of a user equipment (UE) that is roaming on the mobile telecommunications network, wherein the mobile telecommunications network is acting as a visited public land mobile network (VPLMN) for the UE, wherein the updating or building is based at least in part on a map location update received from a mobile call operator (MCO) for the UE;

transmit a visitor location register address of the VSS to a short message service center (SMSC) of a home public land mobile network (HPLMN) of the UE, wherein the SMSC is configured to receive an SMS message for the UE;

using a home location register (HLR) profile provided by an HLR of the HPLMN to determine if the SMS message is to be delivered to the UE using SMS over internet protocol (IP) or SMS over service gateways (SGS) and to provide registration verification services;

maintain a database comprising information about subscribers roaming within the mobile telecommunications network; and

deliver the SMS message to an IP multimedia subsystem (IMS) if the UE supports SMS over IP or to a mobile call operator (MCO) if the UE does not support SMS over IP;

the MCO configured to:

receive the SMS message from the VSS if SMS over SGS is used by the VSS to deliver the SMS message; and

deliver the SMS message to a mobility management entity (MME) to which the UE is attached.

14 . The mobile telecommunications network of claim 13 , further comprising a mobility management entity (MME), wherein the UE is registered by:

receiving, at the MME, an attach request from the UE;

transmitting an SGS location update to the MCO;

transmitting the map update location from the MCO to the VSS; and

receiving the map update location from the MCO.

15 . The mobile telecommunications network of claim 13 , wherein the map update location comprises an international mobile subscriber identity (IMSI) of the UE.

16 . The mobile telecommunications network of claim 13 , wherein the VSS is further configured to transmit an updated map update location message to the HLR of the HPLMN, wherein the updated map update location message comprises a visitor location register (VLR) address of the VSS to be used by the SMSC of the HPLMN to direct the SMS message.

17 . The mobile telecommunications network of claim 13 , wherein the HLR profile comprises a public number of the UE.