Signaling to request increased transmission power limit in an emergency

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

transmitting a message to a base station, wherein the message includes an emergency status of the UE that indicates whether the UE is in an emergency situation, at least one device-to-device (D2D) group, and a requested transmit power to be used for transmitting data from the UE to the at least one D2D group when the UE is in the emergency situation;

receiving a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for D2D communications, wherein the transmit power control information indicates whether the UE can transmit at an allowed transmit power, and wherein the allowed transmit power comprises one of the requested transmit power or a transmit power that is lower than the requested transmit power or lower than a maximum transmission power of the UE; and

transmitting the data to the at least one D2D group based on the transmit power control information received in the DCI message.

2. The method of claim 1 , wherein the allowed transmit power further comprises one of the maximum transmission power of the UE, or an allowed transmission power range.

3. The method of claim 1 , wherein the message indicates an intention to perform D2D communications.

4. The method of claim 3 , wherein the message indicates the at least one D2D group with which the UE intends to communicate based on the status of the UE.

5. The method of claim 1 , further comprising:

receiving a configuration message based on the status, wherein the configuration message indicates the allowed transmit power for the at least one D2D group associated with the UE, wherein the data is transmitted based on the transmit power control information and the allowed transmit power.

6. The method of claim 5 , wherein the allowed transmit power is different from the requested transmit power.

7. The method of claim 1 , further comprising:

receiving information from the base station, wherein the information indicates a maximum transmission power for at least one of a frequency band, a type of UE, or a service subscription, the maximum transmission power being equal to the allowed transmit power.

8. The method of claim 7 , wherein the information is received in a system information block or in a dedicated message.

9. The method of claim 1 , wherein the data is transmitted to the at least one D2D group at the allowed transmission power.

10. The method of claim 1 , wherein the message further includes at least one of a base station identifier, a D2D group identifier, a status start time, or a status stop time.

11. The method of claim 1 , wherein the DCI message further indicates the at least one D2D group to which the data is to be transmitted by the UE at the allowed transmit power.

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

transmitting a message to a base station, wherein the message includes a status of the UE, a buffer status report and a device-to-device (D2D) group index, wherein the D2D group index is associated with a D2D group identifier and a value of the D2D group index corresponds to a position of the D2D group identifier included in a direct communication indication message transmitted by the UE, and wherein the D2D group identifier is associated with a D2D group with which the UE intends to communicate based on the status of the UE;

receiving, by the UE, a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for D2D communications, and wherein the transmit power control information indicates whether the UE can transmit at an allowed transmit power; and

transmitting data based on the transmit power control information received in the DCI message.

13. An apparatus for wireless communication, comprising:

means for transmitting a message to a base station, wherein the message includes an emergency status of the apparatus the indicates whether the apparatus is in an emergency situation, at least one device-to-device (D2D) group, and a requested transmit power to be used for transmitting data from the apparatus to the at least one D2D group when the apparatus is in the emergency situation;

means for receiving a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for D2D communications, wherein the transmit power control information indicates whether the apparatus can transmit at an allowed transmit power, and wherein the allowed transmit power comprises one of the requested transmit power or a transmit power that is lower than the requested transmit power or lower than a maximum transmission power of the apparatus; and

means for transmitting the data to the at least one D2D group based on the transmit power control information received in the DCI message.

14. An apparatus for wireless communication, comprising:

a memory; and

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

transmit a message to a base station, wherein the message includes an emergency status of the apparatus that indicates whether the apparatus is in an emergency situation, at least one device-to-device (D2D) group, and a requested transmit power to be used for transmitting data from the apparatus to the at least one D2D group when the apparatus is in the emergency situation;

receive a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for D2D communications, wherein the transmit power control information indicates whether the apparatus can transmit at an allowed transmit power, and wherein the allowed transmit power comprises one of the requested transmit power or a transmit power that is lower than the requested transmit power or lower than a maximum transmission power of the apparatus; and

transmit the data to the at least one D2D group based on the transmit power control information received in the DCI message.

15. The apparatus of claim 14 , wherein the allowed transmit power further comprises one of the maximum transmission power of the apparatus, a designated transmission power, or an allowed transmission power range.

16. The apparatus of claim 14 , wherein the message indicates an intention to perform D2D communications.

17. The apparatus of claim 16 , wherein the message indicates the at least one D2D group with which the apparatus intends to communicate based on the status of the apparatus.

18. The apparatus of claim 14 , wherein the at least one processor is further configured to:

receive a configuration message based on the status, wherein the configuration message indicates the allowed transmit power for the at least one D2D group associated with the apparatus, wherein the data is transmitted based on the transmit power control information and the allowed transmit power.

19. The apparatus of claim 18 , wherein the allowed transmit power is different from the requested transmit power.

20. The apparatus of claim 14 , wherein the at least one processor is further configured to:

receive information from the base station, wherein the information indicates a maximum transmission power for at least one of a frequency band, a type of apparatus, or a service subscription, the maximum transmission power being equal to the allowed transmit power.

21. The apparatus of claim 20 , wherein the information is received in a system information block or in a dedicated message.

22. The apparatus of claim 14 , wherein the data is transmitted to the at least one D2D group at the allowed transmission power.

23. The apparatus of claim 14 , wherein the message further includes at least one of a base station identifier, a D2D group identifier, a status start time, or a status stop time.

24. The apparatus of claim 14 , wherein the DCI message further indicates the at least one D2D group to which the data is to be transmitted by the apparatus at the allowed transmit power.

25. An apparatus for wireless communication, comprising:

a memory; and

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

transmit a message to a base station, wherein the message includes a status of the apparatus, a buffer status report and a D2D group index, wherein the D2D group index is associated with a D2D group identifier and a value of the D2D group index corresponds to a position of the D2D group identifier included in a direct communication indication message transmitted by the apparatus, and wherein the D2D group identifier is associated with a D2D group with which the apparatus intends to communicate based on the status of the apparatus;

receive, by the apparatus, a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for device-to-device (D2D) communications, and wherein the transmit power control information indicates whether the apparatus can transmit at an allowed transmit power; and

transmit data based on the transmit power control information received in the DCI message.

26. A non-transitory computer-readable medium of a user equipment (UE) storing computer executable code for wireless communication, comprising code for:

transmitting a message to a base station, wherein the message includes an emergency status of the UE that indicates whether the UE is in an emergency situation, at least one device-to-device (D2D) group, and a requested transmit power to be used for transmitting data from the UE to at least one D2D group when the UE is in the emergency situation;

receiving a downlink control information (DCI) message from the base station based on the status, wherein the DCI message includes transmit power control information for device-to-device (D2D) communications, wherein the transmit power control information indicates whether the UE can transmit at an allowed transmit power, and wherein the allowed transmit power comprises one of the requested transmit power or a transmit power that is lower than the requested transmit power or lower than a maximum transmission power of the UE; and

transmitting the data to the at least one D2D group based on the transmit power control information received in the DCI message.