A first transmission of sounding reference signals is on a first cell of a first cell group in parallel with transmission of at least one of a first random access preamble in a second cell group, and a first uplink packet on a second cell. The wireless device drops a second transmission of sounding reference signals in a symbol of the first cell if at least one of the following conditions is satisfied: a second random access preamble is transmitted overlapping the symbol in the first cell group, and a second uplink packet is transmitted overlapping the symbol in the first cell.