Radio communication apparatus, radio communication system, and radio communication method

1. A radio communication apparatus to perform communication with another radio communication apparatus by using a plurality of frequency bands, the apparatus comprising:

a receiving unit configured to receive by using a first frequency band a control message including identification information indicating a second frequency band different from the first frequency band during a random access procedure to said another radio communication apparatus; and

a control unit configured to control data communication between said another radio communication apparatus and the radio communication apparatus by using the second frequency band indicated by the identification information included in the control message, wherein:

the receiving unit is configured to receive by using the first frequency band another control message including other identification information indicating a third frequency band different from the first and second frequency bands during a random access procedure to said another radio communication apparatus; and

the control unit is configured to control data communication between said another radio communication apparatus and the radio communication apparatus by using the third frequency band indicated by the other identification information included in said another control message.

2. The radio communication apparatus according to claim 1 , wherein the control message is a message relating to a signal sequence that is used for a preamble message to be transmitted from the radio communication apparatus to said another radio communication apparatus.

3. The radio communication apparatus according to claim 2 , wherein the control unit controls the radio communication apparatus to transmit the preamble message, based on the control message, to said another radio communication apparatus by using the second frequency band.

4. The radio communication apparatus according to claim 1 , wherein the control message is a response message received from said another radio communication apparatus in response to a preamble message transmitted by the radio communication apparatus.

5. The radio communication apparatus according to claim 4 , wherein:

the control message being the response message further includes timing adjustment information on the second frequency band; and

the control unit controls timing of the data communication using the second frequency band based on the timing adjustment information included in the control message.

6. The radio communication apparatus according to claim 1 , wherein, upon reception of the control message while the second frequency band is in a de active state, the control unit changes a state of the second frequency band into an active state.

7. A radio communication apparatus to perform communication with another radio communication apparatus by using a plurality of frequency bands, the apparatus comprising:

a control unit configured to select a second frequency band different from a first frequency band as a frequency band used for data communication by said another radio communication apparatus; and

a transmitting unit configured to transmit a control message including identification information indicating the second frequency band to said another radio communication apparatus by using the first frequency band during a random access procedure, wherein:

the control unit is configured to select a third frequency band different from the first and second frequency bands as a frequency band used for the data communication by said another radio communication apparatus; and

the transmitting unit is configured to transmit another control message including other identification information indicating the third frequency band to said another radio communication apparatus by using the first frequency band during a random access procedure.

8. A radio communication system to perform communication by using a plurality of frequency bands, the system comprising:

a first radio communication apparatus configured to transmit by using a first frequency band a control message including identification information indicating a second frequency band different from the first frequency band during a random access procedure, and transmit by using the first frequency band another control message including other identification information indicating a third frequency band different from the first and second frequency bands; and

a second radio communication apparatus configured to receive the control message from the first radio communication apparatus by using the first frequency band, receive said another control message from the first radio communication apparatus by using the first frequency band, and perform data communication by using the second frequency band indicated by the identification information included in the control message and the third frequency band indicated by the other identification information included in said another control message.

9. A radio communication method for use in a radio communication system including first and second radio communication apparatus to perform communication by using a plurality of frequency bands, the method comprising:

transmitting, by the first radio communication apparatus, a control message including identification information indicating a second frequency band different from a first frequency band to the second radio communication apparatus by using the first frequency band during a random access procedure performed by the second radio communication apparatus;

receiving, by the second radio communication apparatus, the control message from the first radio communication apparatus by using the first frequency band;

performing, by the second radio communication apparatus, data communication by using the second frequency band indicated by the identification information included in the control message;

transmitting, by the first radio communication apparatus, another control message including other identification information indicating a third frequency band different from the first and second frequency bands to the second radio communication apparatus by using the first frequency band during a random access procedure performed by the second radio communication apparatus;

receiving, by the second radio communication apparatus, said another control message from the first radio communication apparatus by using the first frequency band; and

performing, by the second radio communication apparatus, data communication by using the third frequency band indicated by the other identification information included in said another control message.