A wireless device receives configuration parameters of one or more configured grants of an unlicensed cell. The wireless device receives a downlink control information indicating an uplink grant for a first TB corresponding to a first HARQ process. The wireless device stores, based on a first LBT procedure indicating a busy channel, the first TB in a first HARQ buffer associated with the first HARQ process. The first LBT is for a scheduled transmission of the first TB. The wireless device flushes, based on a second LBT procedure indicating a busy channel, a second HARQ buffer associated with a second HARQ process. The second LBT procedure is for a scheduled transmission of a second TB via a first configured grant of the one or more configured grants.