A mobile station apparatus comprising a wireless unit and a radio resource control unit, the mobile station apparatus communicating with a base station apparatus by carrier aggregation using a plurality of cells including at least a first cell and a second cell, each of the plurality of cells having a different frequency, wherein the mobile station apparatus is characterized in that: the wireless unit is configured to and/or programmed to: receive, from the base station apparatus, a measurement configuration, wherein the measurement configuration includes measurement objects and reporting configurations, one of the measurement objects and one of the reporting configurations are linked by a measurement identifier, each of the measurement objects indicates a measurement frequency, and one or more of the reporting configurations each include a criterion related to event triggered reporting of measurements, the event triggered reporting is a reporting triggered based on evaluation of the criterion relating to an event, the event is related to a measurement reference cell of the plurality of cells, the one or more of the reporting configurations each include an event identifier for selecting the criterion relating to the event; and the radio resource control unit is configured to and/or programmed to: determine (i) the first cell as a measurement reference cell among the plurality of the cells based on a first measurement object linked to a first reporting configuration corresponding to a first event such that a frequency of the first cell is a measurement frequency designated by the first measurement object and (ii) the second cell as a measurement reference cell among the plurality of the cells based on a second measurement object linked to a second reporting configuration corresponding to a second event such that a frequency of the second cell is a measurement frequency designated by the second measurement object, and perform a measurement of the first cell and a measurement of the second cell, wherein (i) a measurement result of the first cell is a measurement result (Ms) of a serving cell in the first event and (ii) a measurement result of the second cell is a measurement result (Ms) of a serving cell in the second event. receive, from the base station apparatus, a measurement configuration, wherein the measurement configuration includes measurement objects and reporting configurations, one of the measurement objects and one of the reporting configurations are linked by a measurement identifier, each of the measurement objects indicates a measurement frequency, and one or more of the reporting configurations each include a criterion related to event triggered reporting of measurements, the event triggered reporting is a reporting triggered based on evaluation of the criterion relating to an event, the event is related to a measurement reference cell of the plurality of cells, the one or more of the reporting configurations each include an event identifier for selecting the criterion relating to the event; and the measurement configuration includes measurement objects and reporting configurations, one of the measurement objects and one of the reporting configurations are linked by a measurement identifier, each of the measurement objects indicates a measurement frequency, and one or more of the reporting configurations each include a criterion related to event triggered reporting of measurements, the event triggered reporting is a reporting triggered based on evaluation of the criterion relating to an event, the event is related to a measurement reference cell of the plurality of cells, the one or more of the reporting configurations each include an event identifier for selecting the criterion relating to the event; and the radio resource control unit is configured to and/or programmed to: determine (i) the first cell as a measurement reference cell among the plurality of the cells based on a first measurement object linked to a first reporting configuration corresponding to a first event such that a frequency of the first cell is a measurement frequency designated by the first measurement object and (ii) the second cell as a measurement reference cell among the plurality of the cells based on a second measurement object linked to a second reporting configuration corresponding to a second event such that a frequency of the second cell is a measurement frequency designated by the second measurement object, and perform a measurement of the first cell and a measurement of the second cell, determine (i) the first cell as a measurement reference cell among the plurality of the cells based on a first measurement object linked to a first reporting configuration corresponding to a first event such that a frequency of the first cell is a measurement frequency designated by the first measurement object and (ii) the second cell as a measurement reference cell among the plurality of the cells based on a second measurement object linked to a second reporting configuration corresponding to a second event such that a frequency of the second cell is a measurement frequency designated by the second measurement object, and perform a measurement of the first cell and a measurement of the second cell, wherein (i) a measurement result of the first cell is a measurement result (Ms) of a serving cell in the first event and (ii) a measurement result of the second cell is a measurement result (Ms) of a serving cell in the second event.