A wireless device receives a radio resource control message from a base station. The radio resource control message comprises one or more configuration parameters for a random access channel. A downlink control information is received that comprises a field indicating a slot format indication, for a slot, among a plurality of SFIs. The plurality of SFIs indicate uplink, flexible, and random access symbols. The wireless device determines radio resources of one or more random access channel occasions of the slot based on the one or more configuration parameters and at least one random access symbol indicated by the slot format indication for the slot. A preamble is transmitted via the radio resources of the one or more random access channel occasions.