TERMINAL DEVICE, BASE-STATION DEVICE, COMMUNICATION SYSTEM, METHOD FOR CONTROLLING TRANSMISSION OF TERMINAL DEVICE, METHOD FOR CONTROLLING TRANSMISSION OF BASE-STATION DEVICE, INTEGRATED CIRCUIT INSTALLED IN TERMINAL DEVICE, AND INTEGRATED CIRCUIT INSTALLED IN BASE-STATION DEVICE

摘要

Provided is a terminal apparatus (1) that is connected to a base-station apparatus (2) by aggregating a plurality of cells. The terminal apparatus groups cells of different frequencies on the basis of a configuration of a transmission timing group which is notified from the base-station apparatus (2), configures a timing reference cell that is used as a reference of an uplink transmission timing of the cells in the group, a group identifier that identifies the group, and a transmission timing timer that indicates available time of the uplink transmission timing of the cells in the group for each group, and releases the configuration of the transmission timing group corresponding to the group in a case where the timing reference cell does not exist in the group due to a modification in a cell on the basis of a modification instruction message which is transmitted from the base-station apparatus (2) and which gives an instruction of changing the cells in the group.