A wireless device receives message(s) configuring transmissions of sounding reference signals on a secondary cell in a secondary cell group. The wireless device transmits one or more of the sounding reference signals on the secondary cell after applying a timing advance command to the secondary cell group. The wireless device is configured to not transmit any of the sounding reference signals on the secondary cell during a period between receiving the message(s) and applying the timing advance command to the secondary cell group.