1. A method for wireless communications by a user equipment (UE), comprising:receiving on a first component carrier (CC) a first physical downlink control channel (PDCCH) order for a first physical random access channel (PRACH) transmission;
determining a transmit power for the first PRACH transmission, based on a retransmission index of the first PRACH transmission;
transmitting the first PRACH on a second CC at the determined transmit power, comprising interrupting communication on the first CC to switch from the first CC to the second CC; and
after transmitting the first PRACH, receiving a second PDCCH order on the first CC before (i) interrupting communication again on the first CC to switch from the first CC to the second CC and (ii) transmitting a second PRACH on the second CC, wherein the second PDCCH order comprises information for triggering the second PRACH.