1. A wireless transmit/receive unit (WTRU) comprising:
a processor; and a transceiver; the processor and the transceiver configured to receive configuration information for reporting a power headroom (PH) associated with each of a plurality of cells, wherein a first cell of the plurality of cells uses first time intervals each having a first length and a second cell of the plurality of cells uses second time intervals each having a second length, and wherein the first length is at least two times the second length; the transceiver configured to transmit, in one of the first time intervals, a first uplink transmission using a first carrier frequency, wherein the first carrier frequency is associated with the first cell; and the processor and the transceiver configured to transmit, in an earliest in time one of the second time intervals that is fully overlapped by the one of the first time intervals, based on the received configuration information, a report including information indicating a first PH corresponding to the one of the first time intervals and a second PH corresponding to the earliest in time one of the second time intervals that is fully overlapped by the one of the first time intervals.
2. The WTRU of claim 1, wherein the report is transmitted in a second uplink transmission using a second carrier frequency, and wherein the second carrier frequency is associated with the second cell.
3. The WTRU of claim 2, wherein the first length is 1 millisecond (ms) and the second length is 0.5 ms.
4. The WTRU of claim 1, wherein the first cell is associated with a first base station that uses a first radio access technology (RAT) and the second cell is associated with a second base station that uses a second RAT.
5. The WTRU of claim 1, wherein the report including information indicating the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest in time one of the second time intervals is included in the first uplink transmission associated with the first cell.
6. The WTRU of claim 1, wherein the report including information indicating the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest in time one of the second time intervals is a type 1 PH report.
7. The WTRU of claim 2, wherein the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest in time one of the second time intervals are determined respectively based on a computed transmit power for the first uplink transmission and a computed transmit power for the second uplink transmission, and wherein the first uplink transmission and the second uplink transmission are transmitted on a physical uplink shared channel (PUSCH).
8. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
receiving configuration information for reporting a power headroom (PH) associated with each of a plurality of cells, wherein a first cell of the plurality of cells uses first time intervals each having a first length and a second cell of the plurality of cells uses second time intervals each having a second length, and wherein the first length is at least two times the second length; transmitting, in one of the first time intervals, a first uplink transmission using a first carrier frequency, wherein the first carrier frequency is associated with the first cell; and transmitting, in an earliest one in time of the second time intervals that is fully overlapped by the one of the first time intervals, based on the received configuration information, a report including information indicating a first PH corresponding to the one of the first time intervals and a second PH corresponding to the earliest in time one of the second time intervals that is fully overlapped by the one of the first time intervals.
9. The method of claim 8, wherein the report is transmitted in a second uplink transmission using a second carrier frequency, and wherein the second carrier frequency is associated with a second cell.
10. The method of claim 9, wherein the first length is 1 millisecond (ms) and the second length is 0.5 ms.
11. The method of claim 8, wherein the first cell is associated with a first base station that uses a first radio access technology (RAT) and the second cell is associated with a second base station that uses a second RAT.
12. The method of claim 8, wherein the report including information indicating the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest in time one of the second time intervals is included in the first uplink transmission associated with the first cell.
13. The method of claim 8, wherein the report including information indicating the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest one in one of the second time intervals is a type 1 PH report.
14. The method of claim 9, wherein the first PH corresponding to the one of the first time intervals and the second PH corresponding to the earliest one in time of the second time intervals are determined respectively based on a computed transmit power for the first uplink transmission and a computed transmit power for the second uplink transmission, and wherein the first uplink transmission and the second uplink transmission are transmitted on a physical uplink shared channel (PUSCH).