A wireless device receives, from a base station, one or more messages comprising configuration parameters of a cell. The configuration parameters indicate a plurality of slot format combinations. The configuration parameters indicate a slot format combination repetition indicator. A downlink control information is received. The downlink control information indicates one of the plurality of slot format combinations. A channel occupancy time structure of the cell is determined based on: the one of the plurality of slot format combinations, and the slot format combination repetition indicator. Transport blocks are transmitted, based on the channel occupancy time structure, via uplink resources of the cell.