A wireless device receives at least one message comprising configuration parameters of a plurality of cells grouped into a plurality of physical uplink control channel (PUCCH) groups. The wireless device transmits, in a subframe and in a first PUCCH group, at least one SRS employing a sounding procedure for the first PUCCH group. The sounding procedure may depend, at least in part, on transmissions of a physical uplink shared channel (PUSCH) or a PUCCH in the first PUCCH group and may be independent of transmissions of PUCCH and PUSCH in a second PUCCH group.