Provided is a method and apparatus for wirelessly transmitting large data in a more efficient and stable manner. In particular, provided is a data slot allocation method used to transmit uncompressed audio/video (AV) data. The data slot allocation method includes transmitting a first superframe during a first beacon period; receiving a data slot request frame from at least one wireless device, which belongs to a network, during a data slot reservation period included in the first superframe; transmitting a response frame to the at least one wireless device during the data slot reservation period in response to the data slot request frame; and transmitting a second superframe including one or more data slots allocated to the at least one wireless device during a second beacon period.