A communications system for exchange of information between communications apparatuses by a multicarrier transmission mode using a plurality of subcarriers, that includes a transmission data generator configured to generate frequency band information indicating which frequency band is to be used for transmission of data between said communication apparatuses; a transmitter configured to transmit the frequency band information, using a specific frequency band, set from among a plurality of frequency band assigned to the communications system, to transmit data using at least one frequency band set from among said plurality of frequency bands; a receiver configured to receive the frequency band information by using the specific frequency band, wherein one or more of said frequency band is assigned not consecutive with said specific frequency band along a frequency axis, and at least one not used subcarrier is inserted between the specific frequency and the frequency band or between said frequency bands.