Communications system having proximity service discovery

1. A proximity services server, comprising:

a memory; and

processing circuitry configured to execute instructions stored in the memory for a watcher application, a location services client, and a list server, wherein the watcher application is configured to:

obtain location information regarding a location of a first mobile communication device from the location services client in response to the first mobile communication device being indicated in a list of information for a second mobile communication device, wherein the first mobile communication device is indicated in the list of information for the second mobile communication device in response to a publication from the first mobile communication device,

obtain user profile information corresponding to the first mobile communication device from a presence server via an IP Multimedia Subsystem (IMS) server,

obtain the list of information for the second mobile communication device from the list server, and

send a message to the second mobile communication device based on the location information and the user profile information.

2. The proximity services server of claim 1 , wherein the location services client is configured to obtain the location information from a Gateway Mobile Location Centre (GMLC).

3. The proximity services server of claim 1 , wherein the watcher application is configured to obtain the user profile information by communicating with a serving call session control function (S-CSCF) of the IMS server, wherein the S-CSCF is configured to communicate with the presence server.

4. The proximity services server of claim 1 , wherein the list server is configured to obtain the list of information from the second mobile communication device.

5. The proximity services server of claim 1 , wherein the list of information comprises user interest information for the second mobile communication device.

6. The proximity services server of claim 1 , wherein the watcher application is further configured to:

receive registration information from the first mobile communication device; and

send a subscription request for the user profile information to the IMS server, wherein the IMS server is configured to send the subscription request to the presence server, and wherein the presence server is configured to process the subscription request.

7. The proximity services server of claim 6 , wherein the registration information includes information regarding a request for notifications regarding a specified user interest.

8. The proximity services server of claim 6 , wherein the watcher application is further configured to

receive a notification regarding a change in the user profile information.

9. The proximity services server of claim 1 , wherein the watcher application is further configured to:

receive a request for a proximity notification of the second mobile communication device;

send a subscription request to a second presence server corresponding to the second mobile communication device;

send a request for location information corresponding to the second mobile communication device to the second presence server; and

receive from the second presence server, the location information.

10. The proximity services server of claim 1 , wherein the watcher application is further configured to:

determine whether the first mobile communication device is in proximity to the second mobile communication device; and

in response to determining that the first mobile communication device is in proximity to the second mobile communication device:

send a first notification message to the first mobile communication device notifying the first mobile communication device that the second mobile communication device is in its proximity; and

send a second notification message to the second mobile communication device notifying the second mobile communication device that the first mobile communication device is in its proximity.

11. A method, comprising:

receiving, at a proximity services server, registration information from a mobile communication device;

sending, from the proximity services server, a subscription request for user profile information to an IP Multimedia Subsystem (IMS) server, wherein the IMS server is configured to send the subscription request to a presence server, and wherein the presence server is configured to process the subscription request;

receiving, at the proximity services server, an acknowledgement of receipt of the subscription request;

storing, at the proximity services server, interest information for the mobile communication device after receiving the acknowledgement of receipt of the subscription request; and

publishing the interest information to other mobile communication devices through the IMS server.

12. The method of claim 11 , wherein the registration information includes information regarding a request for notifications regarding a specified user interest.

13. The method of claim 11 , further comprising:

receiving, at the proximity services server, a notification regarding a change in the user profile information.

14. The method of claim 13 , wherein the presence server sends the notification.

15. The method of claim 13 , wherein the notification is sent in response to the subscription request.

16. A method, comprising:

receiving, at a proximity services server and from a first mobile communication device, a request for a proximity notification of a second mobile communication device;

sending, from the proximity services server, a subscription request to an IP Multimedia Subsystem (IMS) server corresponding to the first mobile communication device;

sending, from the IMS server corresponding to the first mobile communication device, the subscription request to an IMS server corresponding to the second mobile communication device;

sending, from the IMS server corresponding to the second mobile communication device, the subscription request to a presence server corresponding to the second mobile communication device;

sending, from the proximity services server, a request for location information corresponding to the second mobile communication device to the presence server; and

receiving, from the presence server, the location information.

17. The method of claim 16 , further comprising:

receiving, at the proximity services server, an acknowledgement of the subscription request from the presence server.

18. The method of claim 16 , further comprising:

receiving, at the proximity services server, user profile information corresponding to the second mobile communication device from the presence server.

19. The method of claim 16 , further comprising:

determining, at the proximity services server, whether the first mobile communication device is in proximity to the second mobile communication device; and

in response to determining that the first mobile communication device is in proximity to the second mobile communication device:

sending, from the proximity services server, a first notification message to the first mobile communication device notifying the first mobile communication device that the second mobile communication device is in its proximity; and

sending, from the proximity services server, a second notification message to the second mobile communication device notifying the second mobile communication device that the first mobile communication device is in its proximity.

20. The method of claim 19 , wherein determining whether the first mobile communication device is in proximity to the second mobile communication device comprises;

receiving first location information regarding the first mobile communication device from a first Gateway Mobile Location Centre (GMLC);

receiving second location information regarding the second mobile communication device from a second GMLC; and

comparing, at the proximity services server, the first location information and the second location information to determine whether the first mobile communication device is in proximity to the second mobile communication device.