Mobile Station, Radio Base Station and Communication Control Method

1. A mobile station that communicates with a radio base station using equal to or greater than two carriers, wherein the equal to or greater than two carriers include a first carrier and a second carrier, the mobile station comprising: a first communicating unit configured to perform communication with the first carrier and the second carrier using a bandwidth; and a second carrier measuring unit configured to perform measurement of the second carrier, wherein, in a case where a measurement gap for measuring the second carrier is set in the first carrier, the first communicating unit is configured to perform, without changing the bandwidth, communication with the first carrier and the second carrier without considering the measurement gap when the second carrier is activated, and not to perform communication with the first carrier, by changing the bandwidth, in the measurement gap when the second carrier is not activated, and wherein the second carrier measuring unit is configured to perform measurement of received power of the second carrier in the measurement gap when the second carrier is not activated.

2. The mobile station as claimed in claim 1 , wherein, the second carrier measuring unit is configured to perform measurement of the second carrier without using the measurement gap when the second carrier is activated, and to perform measurement of the second carrier using the measurement gap when the second carrier is not activated.

3. The mobile station as claimed in claim 1 , wherein the measurement gap is a time section provided to measure a carrier of a different frequency or a carrier of a different radio communication system.

4. The mobile station as claimed in claim 1 , wherein the first carrier and the second carrier belong to the same frequency band.

5. A communication control method in a mobile station that communicates with a radio base station using equal to or greater than two carriers, wherein the equal to or greater than two carriers include a first carrier and a second carrier, the communication control method comprising: a first step of performing communication with the first carrier and the second carrier using a bandwidth; and a second step of performing measurement of the second carrier, wherein, in the first step, in a case where a measurement gap for measuring the second carrier is set in the first carrier, when the second carrier is activated, the mobile station performs, without changing the bandwidth, communication with the first carrier and the second carrier without considering the measurement gap, and when the second carrier is not activated, the mobile station does not perform communication with the first carrier, by changing the bandwidth, in the measurement gap, and wherein the performing measurement performs measurement of received power of the second carrier in the measurement gap when the second carrier is not activated.