An apparatus may use inactive uplink portions of a downlink CC to transmit SRS to an eNB. At times there may be a collision between the SRS transmission and uplink transmissions or downlink transmissions on another CC. The apparatus receives a carrier aggregation configuration for a first downlink CC and a second CC, determines to transmit an uplink transmission on the second CC or to receive a downlink transmission on the second CC, determines that the SRS would at least partially collide with the uplink transmission or the downlink transmission, and determines to adjust at least one of the uplink transmission, the SRS transmission, or reception of the downlink transmission based on the determination of the collision and an interruption time to transmit the SRS in the uplink portion of the first CC.