Handover destination specification system, mobile terminal, and base station

A mobile terminal in a handover destination specification system that performs a process for specifying a handover destination of the mobile terminal, the mobile terminal comprising:

• a measuring means for measuring reception quality of each cell indicating an accessible area formed by a plurality of base stations capable of being a connection target of the mobile terminal;
• a judging means for judging whether or not the measured reception quality satisfies a predetermined condition;
• a generating means for generating, when judged that the predetermined condition is satisfied, a first message including identification information of the cell satisfying the predetermined condition and information on the reception quality of the cell;
• a transmitting means for transmitting the generated first message to a connection base station to which the mobile terminal itself is currently connected;
• a receiving means for receiving from the connection base station, a second message including information for detecting unique global identification information of the cell of which the reception quality has been measured, based on the first message;
• and
• a processing means for detecting the global identification information of the cell of which reception quality has been measured, based on the received second message, and checking access permission for the detected cell, wherein:
• the generating means, when access permission is confirmed, generates a third message including the global identification information of the cell for which access permission is granted;
• the transmitting means transmits the generated third message to the connection base station;
• the generating means includes, in the first message, reliability information indicating reliability of the cell information of cells for which access permission had been granted in the past, held by the mobile terminal;
• the receiving means receives the second message including a cell list of cells for which the global identification information is to be detected, transmitted from the connection base station based on the reliability information;
• and
• the processing means detects the global identification information based on the cell list, and checks access permission of the cell corresponding to the detected global identification information.

A base station to which a mobile terminal is currently connected in a handover destination specification system that performs a process for specifying a handover destination of the mobile terminal, the base station comprising:

• a receiving means for receiving from the mobile terminal, when reception quality of each cell indicating an accessible range formed by a plurality of base stations capable of being a connection target of the mobile terminal satisfies a predetermined condition, a first message including identification information of the cell satisfying the predetermined condition and information on the reception quality of the cell;
• a generating means for generating a second message including information for detecting unique global identification information of the cell of which reception quality has been measured based on the first message, the second message being a message for the mobile terminal to check access permission to the cell for which the global identification information is detected;
• a transmitting means for transmitting the generated second message to the mobile terminal;
• and
• a judging means for judging whether or not reliability of cell information is low, based on reliability information indicating reliability of cell information of cells for which access permission has been granted in the past, held by the mobile terminal, that is information held in the first message, wherein:
• the generating means, when judged that reliability is low, includes in the second message, a cell list of cells for which the global identification information is to be detected.