WE CLAIM:
1. A mobile communication system comprising:
a base station (72); and
at least one user equipment (71) configured to perform radio communication with the base station;
wherein with the separate use of a plurality of component carriers or with the use of aggregated carriers including the plurality of component carriers aggregated, the base station (72) is configured to perform radio communication with a user equipment (71) corresponding to the component carrier or a user equipment (71) corresponding to the carrier set,
in a case where the base station (72) performs radio communication with the user equipment (71) corresponding to the aggregated carriers with the use of the aggregated carriers, the base station (72) and the user equipment (71) corresponding to the aggregated carriers are configured to transmit each of a plurality of transport blocks created by dividing a transport channel per each of the plurality of component carriers constituting the aggregated carriers, and
the base station (72) and the user equipment (71) corresponding to the aggregated carriers are configured to transmit control information related to radio communication between the base station (72) and the user equipment (71) corresponding to the aggregated carriers so that physical information of the corresponding component carrier is identifiable.
2. The mobile communication system as claimed in Claim 1, wherein the control information is RRC information.
3. The mobile communication system as claimed in Claim 1, wherein the control information is MAC information.

4. The mobile communication system as claimed in Claim 1, wherein the control information is transmitted using a single transport block of the plurality of transport blocks.
5. The mobile communication system as claimed in Claim 1, wherein the control information includes information for identifying physical information of the corresponding component carrier.
6. The mobile communication system as claimed in Claim 1, wherein:
the control information comprises RRC information and MAC information;
the RRC information includes component carrier identification information for identifying the component carrier; and
the MAC information includes information for associating the component carrier identification information with physical information of the component carrier.
7. The mobile communication system as claimed in Claim 1, wherein data is
transmitted using the component carrier selected from a candidate set including aggregated
candidates for the component carriers.
8. The mobile communication system as claimed in Claim 7, wherein the control
information is transmitted using the component carrier included in the candidate set.
9. The mobile communication system as claimed in Claim 7, wherein a
predetermined upper limit is provided to the number of component carriers included in the
candidate set.

10. The mobile communication system as claimed in Claim 7, wherein the contents
of the control information are common to the component carriers included in the candidate
set.
11. The mobile communication system as claimed in Claim 7, wherein a radio
resource for transmitting data related to a part of the component carriers included in the
candidate set is secured.