Configuration of layer-1 destination address for device-to-device communications

1. An apparatus comprising:

a controller configured to receive a discovery request from first User Equipment (UE) that includes an application identifier (ID) assigned to an application within the first UE that provides a proximity service, to identify an application code to announce the first UE during a discovery procedure for the proximity service, and to provide the application code to the first UE;

the controller configured to receive an address request from the first UE to initiate a device-to-device (D2D) communication with at least one second UE identified during the discovery procedure, and to determine whether a D2D context exists for the application ID and the application code;

when a D2D context does not exist for the application ID and the application code, the controller is configured to derive a Layer-1 destination address for the D2D communication based on at least one of the application ID and the application code, and to provide the Layer-1 destination address to the first UE for pre-configuration of the Layer-1 destination address at the first UE before the D2D communication.

2. The apparatus of claim 1 wherein:

when the D2D context exists for the application ID and the application code, the controller is configured to determine that the Layer-1 destination address has previously been derived for the D2D context, to determine whether a validity timer for the Layer-1 destination address has expired, and to use the Layer-1 destination address previously derived if the validity timer has not expired.

3. The apparatus of claim 1 wherein:

the controller is configured to derive the Layer-1 destination address based on a communication mode requested for the D2D communication.

4. The apparatus of claim 3 wherein:

the communication mode comprises unicast, groupcast, or broadcast; and

the Layer-1 destination address is mapped to one communication mode.

5. The apparatus of claim 1 wherein:

the controller is configured to derive the Layer-1 destination address based on a UE identity (ID) for the at least one second UE.

6. The apparatus of claim 1 wherein:

the controller is configured to define a validity timer for the Layer-1 destination address, and to provide the validity timer for the Layer-1 destination address to the first UE; and

the validity timer for the Layer-1 destination address is less than or equal to a validity timer for the application code.

7. The apparatus of claim 1 wherein:

the controller is configured to push the Layer-1 destination address to the at least one second UE for pre-configuration of the Layer-1 destination address at the at least one second UE before the D2D communication.

8. The apparatus of claim 1 wherein:

the controller is configured to receive another address request from the at least one second UE, and to provide the Layer-1 destination address to the at least one second UE for pre-configuration of the Layer-1 destination address at the at least one second UE before the D2D communication in response to the other address request.

9. A method comprising:

receiving a discovery request in a controller in a network from first User Equipment (UE), wherein the discovery request includes an application identifier (ID) assigned to an application within the first UE that provides a proximity service;

identifying an application code to announce the first UE during a discovery procedure for the proximity service;

providing the application code from the controller to the first UE;

receiving an address request from the first UE to initiate a device-to-device (D2D) communication with at least one second UE identified during the discovery procedure;

determining whether a D2D context exists for the application ID and the application code;

when a D2D context does not exist for the application ID and the application code, deriving a Layer-1 destination address for the D2D communication based on at least one of the application ID and the application code, and providing the Layer-1 destination address to the first UE for pre-configuration of the Layer-1 destination address at the first UE before the D2D communication.

10. The method of claim 9 further comprising:

when the D2D context exists for the application ID and the application code, determining that the Layer-1 destination address has previously been derived for the D2D context, determining whether a validity timer for the Layer-1 destination address has expired, and using the Layer-1 destination address previously derived if the validity timer has not expired.

11. The method of claim 9 wherein deriving the Layer-1 destination address comprises:

deriving the Layer-1 destination address based on a communication mode requested for the D2D communication.

12. The method of claim 11 wherein:

the communication mode comprises unicast, groupcast, or broadcast; and

the Layer-1 destination address is mapped to one communication mode.

13. The method of claim 9 wherein deriving the Layer-1 destination address comprises:

deriving the Layer-1 destination address based on a UE identity (ID) for the at least one second UE.

14. The method of claim 9 further comprising:

defining a validity timer for the Layer-1 destination address; and

providing the validity timer for the Layer-1 destination address to the first UE;

wherein the validity timer for the Layer-1 destination address is less than or equal to a validity timer for the application code.

15. The method of claim 9 further comprising:

pushing the Layer-1 destination address to the at least one second UE for pre-configuration of the Layer-1 destination address at the at least one second UE before the D2D communication.

16. The method of claim 9 further comprising:

receiving another address request from the at least one second UE; and

providing the Layer-1 destination address to the at least one second UE for pre-configuration of the Layer-1 destination address at the at least one second UE before the D2D communication in response to the other address request.

17. An apparatus comprising:

first User Equipment (UE) that includes an application that provides a proximity service;

the first UE is configured to transmit a discovery request to a controller in a mobile network that includes an application identifier (ID) assigned to the application, to receive a discovery response from the controller indicating an application code to use to announce the first UE for the proximity service, and to discover at least one second UE for a device-to-device (D2D) communication;

the first UE configured to transmit an address request to the controller for the D2D communication with the at least one second UE, to receive an address response from the controller indicating a Layer-1 destination address for the D2D communication derived by the controller based on at least one of the application ID and the application code, and to initiate the D2D communication using radio resources based on the Layer-1 destination address derived by the controller.

18. The apparatus of claim 17 wherein:

the first UE is configured to insert the application code in the address request.

19. The apparatus of claim 17 wherein:

the first UE is configured to insert a communication mode for the D2D communication in the address request.

20. The apparatus of claim 17 wherein:

the address response from the controller further includes a validity timer for the Layer-1 destination address.