Resource allocation control for long term evolution device-to-device discovery

1. A method of wireless communication of a user equipment (UE), comprising:

determining whether system information is received for device-to-device (D2D) communication;

setting at least one flag based on the system information when the system information is received, wherein a first layer of the UE receives the system information and sets the at least one flag to indicate, to a second layer that is higher than the first layer, whether a request for an allocation of D2D resources is required;

determining the D2D resources based on the at least one flag, wherein the second layer that is higher than the first layer checks the at least one flag to determine whether an action is required by the second layer to enable the first layer to determine the D2D resources; and

sending, by the second layer, a message including a message integrity checksum based on a transmission opportunity time.

2. The method of claim 1 , wherein the system information is determined to have been received for D2D communication, the method further comprising:

determining whether a set of common D2D resources is indicated in the system information; and

determining a radio resource control (RRC) state of the UE,

wherein the at least one flag is set based on whether the set of the common D2D resources is indicated in the system information, and based on the determined RRC state.

3. The method of claim 2 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is unrequired.

4. The method of claim 2 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate that the request for an allocation of the D2D resources is required.

5. The method of claim 2 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

6. The method of claim 2 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

7. The method of claim 1 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is indicated in the system information, the method further comprising:

performing D2D communication using the set of common D2D resources;

stopping the D2D communication through the set of common D2D resources; and

transitioning from an RRC idle state to an RRC connected state;

wherein the at least one flag is set upon transitioning from the RRC idle state to the RRC connected state, and

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

8. The method of claim 1 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is not indicated in the system information, the method further comprising:

performing D2D communication using an allocated set of D2D resources; and

receiving a revocation of the use of the allocated set of D2D resources,

wherein the setting the at least one flag comprises setting a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

9. The method of claim 1 , wherein the first layer is a radio resource control (RRC) layer, and the second layer is a proximity-based service (ProSe) protocol layer.

10. An apparatus for wireless communication, the apparatus being a UE, comprising:

means for determining whether system information is received for device-to-device (D2D) communication;

means for setting at least one flag based on the system information when the system information is received, wherein the apparatus is a user equipment (UE) and a first layer of the UE receives the system information and sets the at least one flag to indicate, to a second layer that is higher than the first layer, whether a request for an allocation of D2D resources is required;

means for determining the D2D resources based on the at least one flag, wherein the second layer that is higher than the first layer checks the at least one flag to determine whether an action is required by the second layer to enable the first layer to determine the D2D resources; and

means for sending, by the second layer, a message including a message integrity checksum based on a transmission opportunity time.

11. The apparatus of claim 10 , wherein the system information is determined to have been received for D2D communication, the apparatus further comprising:

means for determining whether a set of common D2D resources is indicated in the system information; and

means for determining a radio resource control (RRC) state of the UE,

wherein the at least one flag is set based on whether the set of the common D2D resources is indicated in the system information, and based on the determined RRC state.

12. The apparatus of claim 11 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is unrequired.

13. The apparatus of claim 11 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate that the request for an allocation of the D2D resources is required.

14. The apparatus of claim 11 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

15. The apparatus of claim 11 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

16. The apparatus of claim 10 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is indicated in the system information, the apparatus further comprising:

means for performing D2D communication using the set of common D2D resources;

means for stopping the D2D communication through the set of common D2D resources; and

means for transitioning from an RRC idle state to an RRC connected state;

wherein the at least one flag is set upon transitioning from the RRC idle state to the RRC connected state, and

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

17. The apparatus of claim 10 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is not indicated in the system information, the apparatus further comprising:

means for performing D2D communication using an allocated set of D2D resources; and

means for receiving a revocation of the use of the allocated set of D2D resources,

wherein the means for setting the at least one flag is configured to set a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

18. The apparatus of claim 10 , wherein the first layer is a radio resource control (RRC) layer, and the second layer is a proximity-based service (ProSe) protocol layer.

19. An apparatus for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

determine whether system information is received for device-to-device (D2D) communication;

set at least one flag based on the system information when the system information is received;

determine D2D resources based on the at least one flag, wherein the apparatus is a user equipment (UE), wherein a first layer of the UE receives the system information and sets the at least one flag to indicate, to a second layer that is higher than the first layer, whether a request for an allocation of the D2D resources is required, and the second layer that is higher than the first layer checks the at least one flag to determine whether an action is required by the second layer to enable the first layer to determine the D2D resources; and

control the second layer to send a message including a message integrity checksum based on a transmission opportunity time.

20. The apparatus of claim 19 , wherein the system information is determined to have been received for D2D communication, wherein the at least one processor is further configured to:

determine whether a set of common D2D resources is indicated in the system information; and

determine a radio resource control (RRC) state of the UE,

wherein the at least one flag is set based on whether the set of the common D2D resources is indicated in the system information, and based on the determined RRC state.

21. The apparatus of claim 20 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the at least one processor is configured to set the at least one flag by setting a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is unrequired.

22. The apparatus of claim 20 , wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the at least one processor is further configured to set a first flag of the at least one flag to indicate that the request for an allocation of the D2D resources is required.

23. The apparatus of claim 20 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC idle state, and

wherein the at least one processor is further configured to set a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

24. The apparatus of claim 20 , wherein the set of common D2D resources is determined to be not indicated in the system information, and the RRC state is determined to be an RRC connected state, and

wherein the at least one processor is configured to set a first flag of the at least one flag to indicate to the second layer that the request for an allocation of the D2D resources is required.

25. The apparatus of claim 19 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is indicated in the system information, wherein the at least one processor is further configured to:

perform D2D communication using the set of common D2D resources;

stop the D2D communication through the set of common D2D resources; and

transition from an RRC idle state to an RRC connected state;

wherein the at least one flag is set upon transitioning from the RRC idle state to the RRC connected state, and

wherein the at least one processor is configured to set a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

26. The apparatus of claim 19 , wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is not indicated in the system information, wherein the at least one processor is further configured to:

perform D2D communication using an allocated set of D2D resources; and

receive a revocation of the use of the allocated set of D2D resources,

wherein the at least one processor is configured to set a first flag of the at least one flag to indicate that the request for the allocation of the D2D resources is required.

27. A non-transitory computer-readable medium of a user equipment (UE) comprising code that when executed on at least one processor causes the at least one processor to:

determine whether system information is received for device-to-device (D2D) communication;

set at least one flag based on the system information when the system information is received, wherein a first layer of the UE receives the system information and sets the at least one flag to indicate, to a second layer that is higher than the first layer, whether a request for an allocation of D2D resources is required;

determine D2D resources based on the at least one flag, wherein the second layer that is higher than the first layer checks the at least one flag to determine whether an action is required by the second layer to enable the first layer to determine the D2D resources; and

control the second layer to send a message including a message integrity checksum based on a transmission opportunity time.