Mobile station apparatus, base station apparatus, wireless communication system, and wireless communication method

A wireless communication system in which a mobile station apparatus switches a base station apparatus to communicate with by handover, wherein

• a base station apparatus of a handover source decides execution of handover in accordance with a measurement report received from a mobile station apparatus in communication, and transmits a handover command message including scheduled uplink transmission information of a base station apparatus of a handover destination and information on random access to a base station of a handover destination to said mobile station apparatus, and wherein
• the mobile station apparatus having received said handover command message performs uplink transmission to said base station apparatus of a handover destination based on said scheduled uplink transmission information included in said handover command message, and executes a random access procedure to said base station apparatus of a handover destination if a response from said base station apparatus of a handover destination is not received with respect to said uplink transmission even though a number of times of transmission of said uplink transmission has reached a number of times of transmission specified by said uplink transmission information, wherein said random access procedure is a procedure in which the mobile station apparatus transmits a random access preamble to the base station apparatus and the mobile station apparatus receives a response to the random access preamble, and determines that handover has failed if the random access procedure is not completed,
• the mobile station apparatus having received said handover command message including uplink shared channel transmission information of a base station apparatus of a handover destination from said base station apparatus of a handover source, transmits data to an uplink shared channel of said base station apparatus of a handover destination based on said physical uplink shared channel transmission information, and executes the random access procedure to said base station apparatus of a handover destination if a response is not received from said base station apparatus of a handover destination even though a number of times of transmission of data to said uplink shared channel has reached a number of times of retransmission of a hybrid ARQ specified by said uplink shared channel transmission information, and determines that handover has failed if the random access procedure is not completed.

A wireless communication method in which a mobile station apparatus switches a base station apparatus to communicate with by handover, wherein

• a base station apparatus of a handover source decides execution of handover in accordance with a measurement report received from a mobile station apparatus in communication, and transmits a handover command message including scheduled uplink transmission information of a base station apparatus of a handover destination and information on random access to a base station apparatus of a handover destination to said mobile station apparatus in communication, and wherein
• the mobile station apparatus having received said handover command message performs uplink transmission to said base station apparatus of a handover destination based on said scheduled uplink transmission information included in said handover command message, and executes a random access procedure to said base station apparatus of a handover destination if a response from said base station apparatus of a handover destination is not received with respect to said uplink transmission even though a number of times of transmission of said uplink transmission has reached a number of times of transmission specified by said uplink transmission information, wherein said random access procedure is a procedure in which the mobile station apparatus transmits a random access preamble to the base station apparatus and the mobile station apparatus receives a response to the random access preamble, and determines that handover has failed if the random access procedure is not completed,
• the mobile station apparatus having received said handover command message including uplink shared channel transmission information of a base station apparatus of a handover destination from said base station apparatus of a handover source, transmits data to an uplink shared channel of said base station apparatus of a handover destination based on said physical uplink shared channel transmission information, and executes the random access procedure to said base station apparatus of a handover destination if a response is not received from said base station apparatus of a handover destination even though a number of times of transmission of data to said uplink shared channel has reached a number of times of retransmission of a hybrid ARQ specified by said uplink shared channel transmission information, and determines that handover has failed if the random access procedure is not completed.