Provided is a wireless communication system in which high-speed communication is implemented. A receiving device includes an RA managing unit that transmits Msg1 through a PRACH over an SCELL and a D-SR managing unit that transmits a D-SR through a PUCCH over a PCELL before or after the PRACH. A transmitting device includes an RA managing unit that receives Msg1 and a D-SR managing unit that receives the D-SR. The RA managing unit associates a scheduling request with a preamble, and identifies a receiving device.