| 摘要 |
PROBLEM TO BE SOLVED: To provide a mobile station device, a base station device, a communication system, an uplink transmission control method, and an integrated circuit that efficiently control uplink transmission timing per group of respective uplink transmission timing of the mobile station device in the case that the mobile station device supports transmission at multiple uplink transmission timing.SOLUTION: A mobile station device connecting to a base station device by aggregating a plurality of cells groups cells by different frequencies on the basis of an instruction from the base station device, and configures a timing reference cell, a group identifier, and a transmission timing timer per group. If the mobile station device receives a timing reference cell change instruction message, it reconfigures one or several of the timing reference cells, group identifiers, and transmission timing timers of respective groups to which timing reference cells before and after change belong on the basis of a current configuration content and cell information specifying the timing reference cell after change. |
