Aspects are provided that allow a base station to provide a user equipment (UE) multiple timing opportunities to transmit an acknowledgment to a pre-grant (APG) after receiving a pre-grant for a downlink transmission. The base station transmits to the UE a pre-grant for a downlink transmission from the base station, the pre-grant triggering a plurality of timing opportunities for the UE to send an APG to the base station. The UE performs, after receiving the pre-grant, a clear channel assessment (CCA) during at least one timing opportunity of the plurality of timing opportunities. The UE transmits one or more APGs to the base station when the CCA is successful, and the UE receives the downlink transmission from the base station in response to the one or more APGs. The UE transmits the one or more APGs to the base station until the downlink transmission is received from the base station.