Channel allocating method, wireless communication system, and channel structure of wireless sections

A radio communication system, wherein:

• a user terminal transmits a reservation packet to a base station;
• according to the reservation packet, the base station assigns an uplink data channel to the user terminal, and assigns a first shared control channel to the user terminal in association with the uplink data channel, and
• the mobile station transmits a control signal to the base station using the uplink shared control channel associated with the data channel.

A channel structure in a radio section comprising:

• an uplink common control channel that is commonly used for all users belonging to a base station and that transmits a reservation packet from a user terminal;
• and
• a first uplink shared control channel that is assigned to a user terminal in association with an uplink data channel assigned to the user terminal from the base station according to the reservation packet.