Communication system, mobile station device, and communication method

A base station device comprising:

• transmission circuitry configured to and/or programmed to transmit, to a mobile station device, first information via radio resource control (RRC) signaling on a physical downlink shared channel (PDSCH) using a first downlink carrier, and second information on a physical downlink control channel (PDCCH);
• and
• processing circuitry configured and/or programmed to, in a case that the first information is transmitted, communicate with the mobile station device by aggregate use of the first downlink carrier and a second downlink carrier, wherein
• the first information indicates a quantity of physical resource blocks (PRBs) of the second downlink carrier, and
• the second information indicates allocation of one or more physical resource blocks (PRBs) within the physical resource blocks (PRBs) of the second downlink carrier.

A communication method for a mobile station device, the communication method comprising:

• receiving, from a base station device, first information via radio resource control (RRC) signaling on a physical downlink shared channel (PDSCH) using a first downlink carrier, and second information on a physical downlink control channel (PDCCH);
• and
• communicating with the base station device by aggregate use of the first downlink carrier and a second downlink carrier in a case that the first information is received, wherein
• the first information indicates a quantity of physical resource blocks (PRBs) of the second downlink carrier, and
• the second information indicates allocation of one or more physical resource blocks (PRBs) within the physical resource blocks (PRBs) of the second downlink carrier.

A communication method for a base station device, the communication method comprising:

• transmitting, to a mobile station device, first information via radio resource control (RRC) signaling on a physical downlink shared channel (PDSCH) using a first downlink carrier, and second information on a physical downlink control channel (PDCCH);
• and
• communicating with the mobile station device by aggregate use of the first downlink carrier and a second downlink carrier in a case that the first information is transmitted, wherein
• the first information indicates a quantity of physical resource blocks (PRBs) of the second downlink carrier, and
• the second information indicates allocation of one or more physical resource blocks (PRBs) within the physical resource blocks (PRBs) of the second downlink carrier.