Mobile station apparatus, base station apparatus, wireless communication system, control method, and integrated circuit

A mobile station apparatus that is assigned a plurality of cells by a base station apparatus and that performs communication with the base station apparatus via the plurality of cells,

• the plurality of cells being grouped into a first group and a second group, the first group being constituted by one or more cells having a first uplink transmission timing and the first group including a primary cell, the second group being constituted by one or more secondary cells having a second uplink transmission timing that is different from the first uplink transmission timing, and
• the uplink transmission timings being each managed by using a corresponding transmission timing timer for each of the groups, the mobile station apparatus is configured:
• to delete, in a case where a transmission timing timer for the first group has expired, all data that is stored in a transmission HARQ buffer in association with the plurality of cells, and
• to delete, in a case where a transmission timing timer for the second group has expired, data that is stored in the transmission HARQ buffer in association with the cells constituting the second group.

A base station apparatus that assigns a plurality of cells to a mobile station apparatus and that performs communication with the mobile station apparatus via the cells,

• the plurality of cells being grouped into a first group and a second group, the first group being constituted by one or more cells having a first uplink transmission timing and the first group including a primary cell, the second group being constituted by one or more secondary cells having a second uplink transmission timing that is different from the first uplink transmission timing, and
• the uplink transmission timings being each managed by using a corresponding transmission timing timer for each of the groups, the base station apparatus is configured:
• to stop, in a case where a transmission timing timer for the first group has expired, physical-uplink-shared-channel allocation processing for the plurality of cells, and
• to stop, in a case where a transmission timing timer for the second group has expired, physical-uplink-shared-channel allocation processing for the cells constituting the second group.

A control method for controlling a mobile station apparatus that is assigned a plurality of cells by a base station apparatus and that performs communication with the base station apparatus via the cells,

• the plurality of cells being grouped into a first group and a second group, the first group being constituted by one or more cells having a first uplink transmission timing and the first group including a primary cell, the second group being constituted by one or more secondary cells having a second uplink transmission timing that is different from the first uplink transmission timing, and
• the uplink transmission timings being each managed by using a corresponding transmission timing timer for each of the groups, the control method comprising:
• deleting, in a case where a transmission timing timer for the first group has expired, all data that is stored in a transmission HARQ buffer in association with the plurality of cells;
• and
• deleting, in a case where a transmission timing timer for the second group has expired, data that is stored in the transmission HARQ buffer in association with the cells constituting the second group.