A wireless device receives at least one message comprising configuration parameters of a plurality of cells comprising one or more licensed cells and one or more licensed assisted access (LAA) cells. The wireless device transmitting, in a subframe on an LAA cell of the one or more LAA cells, at least one sounding reference signal (SRS) employing a sounding procedure for the one or more LAA cells. The sounding procedure is independent of transmissions of a physical uplink shared channel (PUSCH) in the one or more licensed cells.