Communication device, control device, communication method, and communication program

A communication device includes: a clock unit; a communication unit; a power monitor; a communication speed monitor; a communication volume monitor; a time period identification unit that identifies a time period in which the power consumption of the communication unit exceeds a predetermined power, and a time period in which the communication volume of the communication unit falls below a predetermined communication volume; and a controller that narrows the communication area of the communication unit so that the communication volume monitored by the communication volume monitor is less than or equal to a predetermined communication volume allowed by the communication unit when a current time clocked by the clock unit is in the time period identified by the time period identification unit.