Provided is a data transmission apparatus including a queue management unit to manage at least one queue in which information associated with at least one buffer descriptor (BD) is stored, a scheduler to estimate information to be transmitted among information associated with at least one media access control (MAC) protocol data unit (MPDU) using at least one transmission bitmap (Tx bitmap), a data transmitter to read the estimated information from information associated with a BD indicated in the at least one Tx bitmap, and transmit the read information to a physical layer, and a physical layer management unit to generate information associated with a presentation protocol data unit (PPDU) based on the transmitted information, and transmit the generated information over the air, wherein the at least one BD includes information associated with the at least one MPDU.