Wireless communication system, mobile station and base station

A mobile station for wireless communication using a plurality of cells configured to be grouped so as to comprise a plurality of groups of cells, the mobile station comprising:

• wireless communication circuitry configured to
• receive a first control signal transmitted from a base station, the first control signal including a first field and a second field, the first field comprising first information indicating an amount of adjustment for the mobile station to use to adjust a transmission timing of the mobile station with one or more cells, and the second field being configured to store second information identifying the one or more cells among the plurality of groups of cells, and
• receive a second control signal that includes a third field configured to include a unique identifier of one or more of the plurality of cells, according to which the second information set in the second field of the first control signal is applied to the mobile station;
• and
• a controller configured to, when the unique identifier is included in the second control signal, adjust, using the first information, the transmission timing of the mobile station with the group of cells specified by the second information,
• wherein the first control signal is a Timing Advanced Command (TAC), and
• wherein the second control signal is a Radio Resource Control (RRC) message.

A wireless communication system for wireless communication using a plurality of cells configured to be grouped so as to comprise a plurality of groups of cells, the wireless communication system comprising:

• a base station configured to
• transmit a first control signal that includes a first field and a second field, the first field comprising first information indicating an amount of adjustment for the mobile station to use to adjust a transmission timing of the mobile station with one or more cells, and the second field being configured to store second information identifying the one or more cells among the plurality of groups of cells, and
• transmit a second control signal that includes a third field configured to include a unique identifier of one or more of the plurality of cells, according to which the second information set in the second field of the first control signal is applied to the mobile station;
• and
• a mobile station configured to
• receive the first control signal and the second control signal, and
• when the unique identifier is included in the second control signal, adjust, using the first information, the transmission timing of the mobile station with the group of cells specified by the second information,
• wherein the first control signal is a Timing Advanced Command (TAC), and
• wherein the second control signal is a Radio Resource Control (RRC) message.

A wireless communication method comprising:

• receiving, from a base station configured to use wireless communication with a mobile station by using a plurality of cells configured to be grouped so as to comprise a plurality of groups of cells, a first control signal that includes a first field and a second field, the first field comprising first information indicating an amount of adjustment for the mobile station to use to adjust a transmission timing of the mobile station with one or more cells, and the second field being configured to store second information identifying the one or more cells among the plurality of groups of cells;
• receiving, from the base station, a second control signal that includes a third field configured to include a unique identifier of one or more of the plurality of cells, according to which the second information set in the second field of the first control signal is applied to the mobile station;
• and
• when the unique identifier is included in the second control signal, adjusting, in accordance with the first information, the transmission timing of the mobile station with the group of cells specified by the second information,
• wherein the first control signal is a Timing Advanced Command (TAC), and
• wherein the second control signal is a Radio Resource Control (RRC) message.