The present disclosure relates to a transmission device and reception device for data in a wireless AV system. The transmission device comprises: a processor for encoding media data thereby generating a compressed bitstream; and a communication unit for: fragmenting the compressed bitstream and mapping the compressed bitstream to an MSDU; generating, for transmission of the MSDU, an MPDU frame sequentially comprising an MAC header, a frame body, and an FCS for the MAC header; generating, for the transmission of the MPDU frame, a PPDU sequentially comprising a preamble, at least one PSDU, and a TRN field; and transmitting the PPDU frame through a radio channel. A radio resource for transmission of actually necessary data can be secured by minimizing unnecessary overhead information (i.e., control-related information in the MAC header) from among data transmitted over radio.