System and method for allocating resources for device-to-device communications

1. A method for device-to-device (D2D) communication, the method comprising:

determining, by a device, an availability of a D2D buffer status report (BSR) resource and that the device also has a cellular signal to transmit in a subframe corresponding to a D2D-scheduling request (D2D-SR) resource; and

in response to determining that the D2D BSR resource is unavailable,

generating, by the device, a D2D-SR message in accordance with D2D-SR configuration information, the D2D-SR message requesting allocation of an uplink resource for transmission of a D2D BSR message,

prioritizing, by the device, in accordance with a prioritizing rule, the cellular signal and the D2D-SR message in the subframe corresponding to the D2D-SR resource, and

transmitting, by the device, the D2D-SR message in accordance with the prioritizing.

2. The method of claim 1 , further comprising receiving, by the device, the D2D-SR configuration information.

3. The method of claim 1 , wherein the D2D-SR configuration information specifies that the D2D-SR message is transmitted over a D2D-SR resource and not a cellular SR resource.

4. The method of claim 1 , further comprising identifying a format 3 physical uplink control channel (PUCCH) resource as the D2D-SR resource, and wherein transmitting the D2D-SR message comprises transmitting the D2D-SR message in the format 3 PUCCH resource.

5. The method of claim 4 , wherein the format 3 PUCCH resource is specified by a mathematical formula that is a function of at least one of a D2D-radio network temporary identifier (RNTI), a user equipment identifier (UEID), or a subframe number.

6. The method of claim 1 , further comprising identifying a PUCCH format resource as the D2D-SR resource, and wherein transmitting the D2D-SR message comprises transmitting the D2D-SR message in the PUCCH format resource.

7. The method of claim 1 , further comprising identifying a subset of subframes containing possible D2D-SR resources, and wherein transmitting the D2D-SR message further comprises determining, by the device, that the D2D-SR resource is available when the D2D-SR resource is within the subset of subframes.

8. The method of claim 7 , wherein the subset of subframes is identified with a formula expressible as

(10× n f +└n s /2 ┘−N OFFSET,SR )mod SR PERIODICITY =0,

where n f is a system frame number, n s is a slot number within a radio frame, N OFFSET,SR is a scheduling request (SR) subframe offset, and SR PERIODICITY is a SR periodicity in number of subframes.

9. A device for device-to-device (D2D) communication, comprising:

a processor configured to:

determine an availability of a D2D buffer status report (BSR) resource and that the device also has a cellular signal to transmit in a subframe corresponding to a D2D-scheduling request (D2D-SR) resource; and

in response to determining that the D2D BSR resource is unavailable:

generate a D2D-SR message in accordance with D2D-SR configuration information, wherein the D2D-SR message requests allocation of an uplink resource for transmission of a D2D BSR message, and

prioritize, in accordance with a prioritizing rule, the cellular signal and the D2D-SR message in the subframe corresponding to the D2D-SR resource; and

a transmitter operatively coupled to the processor and configured to transmit the D2D-SR message in accordance with the prioritizing.

10. The device of claim 9 , further comprising a receiver operatively coupled to the processor and configured to receive the D2D-SR configuration information.

11. The device of claim 9 , wherein the D2D-SR configuration information specifies that the D2D-SR message is transmitted over a D2D-SR resource and not a cellular SR resource.

12. The device of claim 9 , further comprising the processor configured to identify a format 3 physical uplink control channel (PUCCH) resource as the D2D-SR resource, wherein the transmitter configured to transmit the D2D-SR message comprises the transmitter configured to transmit the D2D-SR message in the format 3 PUCCH resource.

13. The device of claim 12 , wherein the format 3 PUCCH resource is specified by a mathematical formula that is a function of at least one of a D2D-radio network temporary identifier (RNTI), a user equipment identifier (UEID), or a subframe number.

14. The device of claim 9 , further comprising the processor configured to identify a PUCCH format resource as the D2D-SR resource, wherein the transmitter configured to transmit the D2D-SR message comprises the transmitter configured to transmit the D2D-SR message in the PUCCH format resource.

15. The device of claim 9 , further comprising the processor configured to:

identify a subset of subframes containing possible D2D-SR resources; and

determine that the D2D-SR resource is available when the D2D-SR resource is within the subset of subframes.

16. The device of claim 15 , wherein the subset of subframes is identified with a formula expressible as

(10× n f +└n s /2┘− N OFFSET,SR )mod SR PERIODICITY =0,

where n f is a system frame number, n s is a slot number within a radio frame, N OFFSET,SR is a scheduling request (SR) subframe offset, and SR PERIODICITY is a SR periodicity in number of subframes.

17. A device for device-to-device (D2D) communication, comprising:

a non-transitory memory storage comprising instructions; and

a processor in communication with the non-transitory memory storage, wherein the processor executes the instructions to cause the device to:

determine an availability of a D2D buffer status report (BSR) resource and that the device also has a cellular signal to transmit in a subframe corresponding to a D2D-scheduling request (D2D-SR) resource;

in response to determining that the D2D BSR resource is unavailable:

generate a D2D-SR message in accordance with D2D-SR configuration information, wherein the D2D-SR message requests allocation of an uplink resource for transmission of a D2D BSR message, and

prioritize, in accordance with a prioritizing rule, the cellular signal and the D2D-SR message in the subframe corresponding to the D2D-SR resource; and

transmit the D2D-SR message in accordance with the prioritizing.

18. The device of claim 17 , wherein the processor executes the instructions to cause the device to receive the D2D-SR configuration information.

19. The device of claim 17 , wherein the D2D-SR configuration information specifies that the D2D-SR message is transmitted over a D2D-SR resource and not a cellular SR resource.

20. The device of claim 17 , wherein the processor executes the instructions to cause the device to:

identify a format 3 physical uplink control channel (PUCCH) resource as the D2D-SR resource; and

transmit the D2D-SR message in the format 3 PUCCH resource.

21. The device of claim 20 , wherein the format 3 PUCCH resource is specified by a mathematical formula that is a function of at least one of a D2D-radio network temporary identifier (RNTI), a user equipment identifier (UEID), or a subframe number.

22. The device of claim 17 , wherein the processor executes the instructions to cause the device to:

identify a PUCCH format resource as the D2D-SR resource; and

transmit the D2D-SR message in the PUCCH format resource.

23. The device of claim 17 , wherein the processor executes the instructions to cause the device to:

identify a subset of subframes containing possible D2D-SR resources; and

determine that the D2D-SR resource is available when the D2D-SR resource is within the subset of subframes.

24. The device of claim 23 , wherein the subset of subframes is identified with a formula expressible as

(10× n f +└n s /2┘ −N OFFSET,SR )mod SR PERIODICITY =0,

where n f is a system frame number, n s is a slot number within a radio frame, N OFFSET,SR is a scheduling request (SR) subframe offset, and SR PERIODICITY is a SR periodicity in number of subframes.