Base station apparatus, mobile station apparatus, mobile communication system, communication method, control program, and integrated circuit

A processing method performed in a mobile station apparatus that is configured and/or programmed to communicate with a base station apparatus by using a plurality of cells grouped into a plurality of transmission timing cell groups, the processing method comprising:

• obtaining a parameter;
• performing transmission of a preamble;
• setting a counter incremented based on transmission of the preamble;
• determining to indicate a random access problem corresponding to one transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the one transmission timing cell group,
• the one transmission timing cell group being one of the plurality of transmission timing cell groups, and
• determining not to indicate a random access problem corresponding to another transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the another transmission timing cell group,
• the another transmission timing cell group being one of the plurality of transmission timing cell groups.

A processing apparatus mounted in a mobile station apparatus that is configured and/or programmed to communicate with a base station apparatus by using a plurality of cells grouped into a plurality of transmission timing cell groups, the processing apparatus comprising:

• an obtaining circuitry configured and/or programmed to obtain a parameter;
• a transmission circuitry configured and/or programmed to perform transmission of a preamble;
• and
• a control circuitry configured and/or programmed to set a counter incremented based on transmission of the preamble, wherein
• the control circuitry is further configured and/or programmed to:
• indicate a random access problem corresponding to one transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the one transmission timing cell group,
• the one transmission timing cell group being one of the plurality of transmission timing cell groups;
• and
• not indicate a random access problem corresponding to another transmission timing cell group in a case where the counter reaches the parameter +1 and the transmission of the preamble is performed on the another transmission timing cell group,
• the another transmission timing cell group being one of the plurality of transmission timing cell groups.