Patent ID: 8824402

Claim:
An apparatus for transmitting data in a communication system, comprising: a transmitting unit configured to transmit a null data packet announcement (NDPA) frame and a null data packet (NDP) frame to a terminal so as to acquire channel information of the terminal for transmitting and receiving data through beamforming according to multi-input multi-output (MIMO); a receiving unit configured to receive a beamforming frame from the terminal as a response of the null data packet announcement frame and the null data packet frame; and a checking unit configured to check indication information on whether the null data packet frame included in the a control information field of the beamforming frame is normally received, wherein the transmitting unit retransmits the data packet announcement frame and the null data packet frame to the terminal or transmit a beamforming-poll frame to the terminal according to the indication information on whether the null data packet frame is normally received.