Control system, radio telephone device, control method and program

A control system comprising:

• a first wireless telephone terminal;
• a second wireless telephone terminal;
• and
• a wireless mobile object,
• wherein the first wireless telephone terminal includes:
• a call placement/reception unit, implemented using one or more computing devices, that establishes a voice channel over a mobile communication network with the second wireless telephone terminal and the wireless mobile object by using a multi-point call function of controlling a voice call among a plurality of points, and
• a control unit, implemented using one or more computing devices, that controls the wireless mobile object by transmitting a control signal to the wireless mobile object through the voice channel, and that transmits, to the second wireless telephone terminal through the voice channel, a change signal for changing a user who maneuvers the wireless mobile object based on strength of radio waves from the wireless mobile object being decreased to less than a threshold value,
• wherein the second wireless telephone terminal includes:
• a call placement/reception unit, implemented using one or more computing devices, that establishes the voice channel over the mobile communication network with the first wireless telephone terminal and the wireless mobile object by using the multi-point call function, and
• a control unit, implemented using one or more computing devices, that controls the wireless mobile object by transmitting a control signal to the wireless mobile object through the voice channel based on the change signal being received from the first wireless telephone terminal, and
• wherein the wireless mobile object includes:
• a call placement/reception unit, implemented using one or more computing devices, that establishes the voice channel over the mobile communication network with the first wireless telephone terminal and the second wireless telephone terminal by using the multi-point call function, and
• a control unit, implemented using one or more computing devices, that controls an action of the wireless mobile object, based on (i) the control signal received from the first wireless telephone terminal through the voice channel or (ii) the control signal received from the second wireless telephone terminal through the voice channel.