A data transmission apparatus in a communication system includes a verification unit configured to verify a basic frequency band capable of being used for transmitting and receiving data to and from a plurality of terminals, and a multi-bandwidth mode in the basic frequency band; a generation unit configured to generate data packets in the multi-bandwidth mode; and a transmission unit configured to transmit the data packets in the multi-bandwidth mode, wherein the multi-bandwidth mode includes a ½× bandwidth of the basic frequency band, a basic bandwidth, a 2× bandwidth of the basic frequency band, a 4× bandwidth of the basic frequency band and an 8× bandwidth of the basic frequency band.