Radio station and communication system

A radio station comprising:

• a receiver configured to receive a first signal from another radio station according to a transmission opportunity for the first signal that requests a radio resource, and
• a transmitter configured to transmit information on the radio resource from the another radio station, the radio resource being allocated to data in the bundled channel and is not allocated to data in a channel not included in the bundled channel, wherein
• the transmission opportunity is generated according to an amount of data in a bundled channel and the first information related to the bundled channel, or
• the transmission opportunity is generated when a timer corresponding to the bundled channel expires.

A radio system comprising:

• a first radio station configured to:
• control to generate a transmission opportunity for a first signal that requests a radio resource,
• transmit the first signal according to the transmission opportunity, and
• receive information on the radio resource, the radio resource being allocated to data in the bundled channel and is not allocated to data in a channel not included in the bundled channel;
• and
• a second radio station configured to:
• receive the first signal, and
• transmit the information on the radio resource, wherein
• the first radio station is further configured to:
• control to generate, according to an amount of data in a bundled channel and the first information related to the bundled channel, the transmission opportunity, or
• control to generate, when a timer corresponding to the bundled channel expires, the transmission opportunity.