Apparatus and method for reserving communication medium

An apparatus and a method for reserving communication media are provided to increase the efficiency of channel use by dividing a channel into a plurality of subchannels and making a separate reservation for a communication medium allocated to each of the subchannels. An apparatus for reserving communication media comprises the first PHY(PHYsical) unit(550) and the second PHY unit(560). The first PHY unit(550) transmits a frame through the first communication medium in order to reserve a communication medium for one among many channels. The first PHY unit(550) comprises the first baseband processor(551), the first RF unit(552), and the first antenna(553). The first baseband processor(551) creates the frame. The first RF unit(552) converts the frame into an RF signal. The first antenna(553) transmits the RF signal. Also, the first PHY unit(550) reserves a communication medium which transmits and receives control frames through the first communication medium. The second PHY unit(560) transmits certain data through the second communication medium reserved by the frame transmitted from the first PHY unit(550).