A mobile station device in a communication system performing a non-contention based random access procedure, the mobile station device comprising: a radio unit configured to receive, from a base station device, a dedicated preamble ID; and a message processor configured to generate a preamble by using the dedicated preamble ID, and control the radio unit to transmit, to the base station device, the preamble, the mobile station device being characterized in that the radio unit is configured to: receive, from the base station device, random access resource information, transmit, to the base station device, the preamble by using a Random Access CHannel resource specified by the random access resource information, monitor whether a random access response to the preamble is received from the base station device within a predetermined period after the preamble is transmitted, wherein the predetermined period is determined by information informed by the base station device, and retransmit, to the base station device, the random access preamble by using the Random Access CHannel resource specified by the random access resource information in a case that the random access response fails to be received within the predetermined period. a radio unit configured to receive, from a base station device, a dedicated preamble ID; and a message processor configured to generate a preamble by using the dedicated preamble ID, and control the radio unit to transmit, to the base station device, the preamble, generate a preamble by using the dedicated preamble ID, and control the radio unit to transmit, to the base station device, the preamble, the mobile station device being characterized in that the radio unit is configured to: receive, from the base station device, random access resource information, transmit, to the base station device, the preamble by using a Random Access CHannel resource specified by the random access resource information, monitor whether a random access response to the preamble is received from the base station device within a predetermined period after the preamble is transmitted, wherein the predetermined period is determined by information informed by the base station device, and retransmit, to the base station device, the random access preamble by using the Random Access CHannel resource specified by the random access resource information in a case that the random access response fails to be received within the predetermined period. receive, from the base station device, random access resource information, transmit, to the base station device, the preamble by using a Random Access CHannel resource specified by the random access resource information, monitor whether a random access response to the preamble is received from the base station device within a predetermined period after the preamble is transmitted, wherein the predetermined period is determined by information informed by the base station device, and wherein the predetermined period is determined by information informed by the base station device, and retransmit, to the base station device, the random access preamble by using the Random Access CHannel resource specified by the random access resource information in a case that the random access response fails to be received within the predetermined period.