A wireless device receives one or more messages. The one or more messages comprise configuration parameters of a cell. The configuration parameters indicate: a plurality of slot format combinations of the cell; a plurality of reference signals (RS) of the cell; and a channel occupancy time (COT) radio network temporary identifier (RNTI). The wireless device receives a downlink control information (DCI) scrambled by the COT-RNTI indicating a slot format combination of the plurality of slot format combinations, for an RS of the plurality of RSs. A channel occupancy time (COT) structure is determined for the RS based on the slot format combination. A transport block is transmitted, via uplink resources of the cell, based on the COT structure.