A terminal is disclosed that includes a processor that includes, in capability information, a separation class indicating a frequency separation between a lower edge of a component carrier with a lowest frequency for supported intra-band non-contiguous carrier aggregation and an upper edge of a component carrier with a highest frequency for the supported intra-band non-contiguous carrier aggregation. The terminal further includes a transmitter that transmits the capability information to a base station, where the separation class is indicated by an index to identify a class of the frequency separation. In other aspects, a transmission method and a radio communication system are also disclosed.