Base station device, mobile station device, wireless communication system, program, random access response transmitting method, and random access response receiving method

A base station device that performs wireless communication with a mobile station device, comprising:

• a random access identification information storage that stores random access identification information and mobile station device identification information correlated with the random access identification information, the random access identification information being allocated by the base station device to the mobile station device, and the mobile station device identification information identifying the mobile station device;
• a random access receiver that receives random access identification information transmitted by the mobile station device having performed random access;
• a scheduler that, if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, determines whether to transmit random access response information that is a response to the random access corresponding to the random access identification information received by using the mobile station device identification information, or by using identification information having not been allocated to a specific mobile station device, the identification information being allocated for transmitting the response to the random access;
• and
• a transmitter that allocates and transmits the random access response information based on the determination by the scheduler,
• wherein if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, the scheduler determines, based on an amount of downlink traffic, whether to transmit the random access response information by using the mobile station device identification information or by using the identification information.

A base station device that performs wireless communication with a mobile station device, comprising:

• a random access identification information storage that stores random access identification information and mobile station device identification information correlated with the random access identification information, the random access identification information being allocated by the base station device to the mobile station device, and the mobile station device identification information identifying the mobile station device;
• a random access receiver that receives random access identification information transmitted by the mobile station device having performed random access;
• a scheduler that, if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, determines whether to transmit random access response information that is a response to the random access corresponding to the random access identification information received by using the mobile station device identification information, or by using identification information having not been allocated to a specific mobile station device, the identification information being allocated for transmitting the response to the random access;
• and
• a transmitter that allocates and transmits the random access response information based on the determination by the scheduler,
• wherein if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, the scheduler determines, based on the number of pieces of random access response information to be simultaneously transmitted, whether to transmit the random access response information by using the mobile station device identification information or by using the identification information.

A wireless communication system comprising a mobile station device and a base station device that performs wireless communication with the mobile station device, wherein

• if the mobile station device has transmitted, by performing random access, random access identification information allocated to the mobile station device, the random access identification information being for identifying the random access performed by the mobile station device, the mobile station device monitors identification information and mobile station device identification information, the identification information having not been allocated to a specific mobile station device, the identification information being allocated for transmitting a response to the random access performed by the mobile station device, and the mobile station device identification information being allocated to the mobile station device, and
• the base station device comprises:
• a random access identification information storage that stores random access identification information and mobile station device identification information correlated with the random access identification information, the random access identification information being allocated by the base station device to the mobile station device, and the mobile station device identification information identifying the mobile station device;
• a random access receiver that receives random access identification information transmitted by the mobile station device having performed random access;
• a scheduler that, if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, determines whether to transmit random access response information that is a response to the random access corresponding to the random access identification information received by using the mobile station device identification information, or by using identification information having not been allocated to a specific mobile station device, the identification information being allocated for transmitting the response to the random access;
• and
• a transmitter that allocates and transmits the random access response information based on the determination by the scheduler.