Patent ID: 7436809

Claim:
A communicating system having a base station and a plurality of mobile stations that radio-communicate through an uplink channel and a downlink channel with frames each of which is composed of a plurality of time divided slots, each of the frames of the uplink channel and the downlink channel being transmitted in accordance with OFDM transmitting system, an OFDM sub carrier used in the OFDM transmitting system being divided, each of the frames of the uplink channel and the downlink channel being allocated to the divided portions of the OFDM sub carrier to form a plurality of sub channels that are independent from each other, a plurality of frames of the uplink channel and downlink channel being radio-communicated between one base station and the plurality of mobile stations through the sub channels, a frame control message slot (FCMS) being allocated to each frame of the sub channel of the downlink channel, slot allocation information of the uplink channel, slot allocation information of the downlink channel, response information against data transmitted through the uplink channel, response information against connection setup—connection release request transmitted from one of the mobile stations, and response information against registration—deregistration request transmitted from one of the mobile stations being transmitted from the base station to one of the mobile stations with the frame control message slot, an activation slot (ACTS) being allocated to each frame of the sub channel of the uplink channel, the connection setup—connection release request and the registration—deregistration request transmitted from one of the mobile stations being transmitted from one of the mobile stations to the base station with the activation slot (ACTS), one of the mobile stations receiving all the divided portions of the OFDM sub carrier transmitted in accordance with the OFDM transmission system from the base station through the downlink channel, the frame message control slot allocated to all the received sub channels being received, the allocated information of the frames of the uplink and downlink channels being received, an available one of the sub channels being determinable based on the allocated information, a registration request being performed for the activation slot of the available sub channel, a communication being performed with the frames of the uplink and the downlink channels allocated to the sub channel that has been registered.