BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a configuration of a first embodiment of the invention;
FIG. 2 is a view showing a structure of a sensor net terminal as well as a base station according to the first embodiment of the invention;
FIG. 3 is a block diagram showing a configuration of a second embodiment of the invention;
FIG. 4 is a view showing logic levels of a power supply voltage determination means according to the second embodiment of the invention;
FIG. 5 is a block diagram showing a configuration of a third embodiment of the invention;
FIG. 6 is a view showing a structure of a sensor net terminal as well as a base station according to the third embodiment of the invention;
FIG. 7 is a block diagram showing a configuration of a fourth embodiment of the invention; and
FIG. 8 is a view showing logic levels of a power supply voltage determination means according to the fourth embodiment of the invention.