Communication control device, communication control method, and terminal device

1. A communication control device comprising:

processing circuitry configured to:

acquire information about a terminal device that uses one component carrier of a macro cell as a primary component carrier,

set one or more component carriers of a small cell partially or fully overlapping with the macro cell as an additional component carrier to be used additionally by the terminal device,

set one component carrier among the one or more component carriers as a special component carrier on which the terminal device is able to transmit uplink control information on an uplink control channel, and

set a component carrier not set as the special component carrier from among the one or more component carriers of the small cell as a secondary component carrier associated with the special component carrier,

wherein uplink control information related to the associated secondary component carrier is information transmitted on the uplink control channel of the special component carrier,

wherein the special component carrier is a component carrier on which a connection establishment procedure is not conducted by the terminal device,

wherein when a radio link failure occurs on the special component carrier, the processing circuitry newly sets, as the special component carrier, one component carrier currently set as the secondary component carrier, via a prescribed procedure, and

wherein the prescribed procedure is a connection reconfiguration procedure or a connection re-establishment procedure for changing the special component carrier.

2. The communication control device according to claim 1 , wherein the uplink control information includes an acknowledgement (ACK) and a negative acknowledgement (NACK) regarding reception of a downlink signal.

3. The communication control device according to claim 1 , wherein the uplink control information includes an uplink scheduling request.

4. The communication control device according to claim 1 , wherein the uplink control information includes periodically reported channel state information.

5. The communication control device according to claim 1 , wherein the uplink control channel is a physical uplink control channel (PUCCH).

6. The communication control device according to claim 1 , wherein the special component carrier is a component carrier selected for each terminal device.

7. The communication control device according to claim 1 , wherein when newly setting a component carrier of the small cell as the additional component carrier, when the processing circuitry sets the relevant component carrier as the special component carrier, the processing circuitry notifies the terminal device of the addition of the component carrier as the special component carrier.

8. The communication control device according to claim 1 , wherein

the secondary component carrier is a component carrier on which the terminal device is unable to transmit the uplink control information on the uplink control channel.

9. The communication control device according to claim 8 , wherein when newly setting a component carrier of the small cell as the additional component carrier, when the processing circuitry sets the relevant component carrier as the secondary component carrier, the processing circuitry notifies the terminal device of the addition of the component carrier as the secondary component carrier.

10. The communication control device according to claim 8 , wherein the processing circuitry changes the special component carrier by newly setting, as the special component carrier, one component carrier currently set as the secondary component carrier.

11. The communication control device according to claim 10 , wherein after the special component carrier is changed, another component carrier currently set as the secondary component carrier is associated with the one component carrier newly set as the special component carrier.

12. The communication control device according to claim 10 , wherein when changing the special component carrier, the processing circuitry notifies the terminal device that the special component carrier is changed to the one component carrier newly set as the special component carrier.

13. The communication control device according to claim 12 , wherein the processing circuitry notifies the terminal device that the special component carrier is changed to the one component carrier newly set as the special component carrier in a message during a connection reconfiguration procedure.

14. The communication control device according to claim 1 , wherein when the prescribed procedure does not complete within a prescribed period, the processing circuitry stops usage of the special component carrier and the secondary component carrier associated with the special component carrier by the terminal device.

15. The communication control device according to claim 1 , wherein when a backhaul between a base station of the macro cell and a base station of the small cell does not satisfy a prescribed quality standard, the processing circuitry sets the one component carrier among the one or more component carriers as the special component carrier, whereas when the backhaul satisfies the prescribed quality standard, the processing circuitry sets each of the one or more component carriers as a secondary component carrier associated with the primary component carrier.

16. A communication control method comprising:

acquiring information about a terminal device that uses one component carrier of a macro cell as a primary component carrier;

setting, by a processor, one or more component carriers of a small cell partially or fully overlapping with the macro cell as an additional component carrier to be used additionally by the terminal device;

setting, by the processor, one component carrier among the one or more component carriers as a special component carrier on which the terminal device is able to transmit uplink control information on an uplink control channel; and

setting, by the processor, a component carrier not set as the special component carrier from among the one or more component carriers of the small cell as a secondary component carrier associated with the special component carrier,

wherein uplink control information related to the associated secondary component carrier is information transmitted on the uplink control channel of the special component carrier,

wherein the special component carrier is a component carrier on which a connection establishment procedure is not conducted by the terminal device,

wherein when a radio link failure occurs on the special component carrier, the processor newly sets, as the special component carrier, one component carrier currently set as the secondary component carrier, via a prescribed procedure, and

wherein the prescribed procedure is a connection reconfiguration procedure or a connection re-establishment procedure for changing the special component carrier.

17. A terminal device comprising:

processing circuitry configured to:

set, when the terminal device uses one component carrier of a macro cell as a primary component carrier, one or more component carriers of a small cell partially or fully overlapping with the macro cell as an additional component carrier to be used additionally by the terminal device, wherein one component carrier among the one or more component carriers is set as a special component carrier on which the terminal device is able to transmit uplink control information on an uplink control channel, wherein a component carrier not set as the special component carrier from among the one or more component carriers of the small cell is set as a secondary component carrier associated with the special component carrier, and

control wireless communication on the one component carrier so that the uplink control information is transmitted on the uplink control channel of the one component carrier, wherein uplink control information related to the associated secondary component carrier is information transmitted on the uplink control channel of the special component carrier,

wherein the special component carrier is a component carrier on which a connection establishment procedure is not conducted by the terminal device,

wherein when a radio link failure occurs on the special component carrier, one component carrier currently set as the secondary component carrier is newly set as the special component carrier via a prescribed procedure, and

wherein the prescribed procedure is a connection reconfiguration procedure or a connection re-establishment procedure for changing the special component carrier.