A wireless communication device (AP1, S1, S2) in a wireless communication system which transmits a wireless frame to be transmitted within a predetermined time period (L), the wireless communication device (AP1, S1, S2) comprising: a transmission unit configured to transmit the wireless frame; a carrier sense unit configured to check whether or not any carrier is being transmitted from other wireless communication devices; and a control unit for controlling transmission of the wireless frame; characterized by a transmission time calculating unit configured to calculate a necessary transmission time (N1, N2) which is an estimated time period taken from start of the transmission of the wireless frame to completion of the transmission; a time-out time calculating unit configured to calculate a time-out time (T1, T2) from the predetermined time period (L) and the necessary transmission time (N1, N2); and a frame transmission determining unit configured to compare a carrier detection time (C1, C2) with the time-out time (T1, T2) to determine whether to transmit or discard the wireless frame, and notify the control unit of a result of the determination, the carrier detection time (C1, C2) being a time period during which a carrier notified from the carrier sense unit is detected; wherein the control unit is configured to, based on the result of the determination notified from the frame transmission determining unit , notify the transmission unit that the wireless frame is to be transmitted when the frame transmission determining unit determines to transmit the wireless frame, and discard the wireless frame when the frame transmission determining unit determines to discard the wireless frame. a transmission unit configured to transmit the wireless frame; a carrier sense unit configured to check whether or not any carrier is being transmitted from other wireless communication devices; and a control unit for controlling transmission of the wireless frame; characterized by a transmission time calculating unit configured to calculate a necessary transmission time (N1, N2) which is an estimated time period taken from start of the transmission of the wireless frame to completion of the transmission; a time-out time calculating unit configured to calculate a time-out time (T1, T2) from the predetermined time period (L) and the necessary transmission time (N1, N2); and a frame transmission determining unit configured to compare a carrier detection time (C1, C2) with the time-out time (T1, T2) to determine whether to transmit or discard the wireless frame, and notify the control unit of a result of the determination, the carrier detection time (C1, C2) being a time period during which a carrier notified from the carrier sense unit is detected; wherein the control unit is configured to, based on the result of the determination notified from the frame transmission determining unit , notify the transmission unit that the wireless frame is to be transmitted when the frame transmission determining unit determines to transmit the wireless frame, and discard the wireless frame when the frame transmission determining unit determines to discard the wireless frame. <EOS>