A user device (UE) for scheduling an uplink transmission assignment with a base station that communicates with the user device via a shared carrier, receives, from the base station, a configuration that indicates (i) a first channel access procedure for the user device to perform prior to transmitting an uplink transmission and (ii) at least one occasion at which the user device is to transmit the uplink transmission (1602); receives, from the base station via the shared carrier, a signal indicating at least a portion of a transmission time period during which the shared carrier is available to the base station (1604); and performs the first channel access procedure or a second channel access procedure before transmitting the uplink transmission based at least in part on whether the occasion is within the transmission time period (1606).