A communications device for performing wireless communications includes a data receiving section for receiving data by wireless communications, a mode switching section for switching an operation mode of the communications device between a first mode in which power is supplied to the data transmitting section, and a second mode inWhich power consumption in at least theData transmitting section is minimized over that in the first mode.
A communications device for performing wireless communications includes: a data receiving section for receiving data by wireless communications; a data transmitting section for transmitting data by wireless communications; a mode switching section for switching an operation mode of the communications device between a first mode in which power is supplied to the data transmitting section, and a second mode in which power consumption in at least the data transmitting section is minimized over that in the first mode; and a determination section for determining whether the data receiving section has received designated data. The mode switching section switches the operation mode of the communications device from the second mode to the first mode if, in a state in which the communications device is in the second mode, the determination section has determined that the data receiving section has received the designated data.