A wireless device receives radio resource control (RRC) message(s) comprising configuration parameters for cells comprising licensed assisted access (LAA) cells. Uplink grants for the LAA cells are received. An uplink grant in the uplink grants indicates a channel access priority class. The uplink grants are grouped into grouped grants. A first grouped grant in the grouped grants comprises a first plurality of uplink grants each indicating a same first channel access priority class. Radio resources are allocated, indicated by the first grouped grant, to one or more first logical channels. A plurality of transport blocks corresponding to the first plurality of grants are generated and transmitted.