RADIO COMMUNICATIONS SYSTEM, RADIO TERMINAL DEVICE, AND RADIO COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a radio communications system capable of increasing reliability of data reception from a terminal device and saving power consumption of the terminal device.SOLUTION: A radio communications system includes a radio communication device for returning a response including own identification information when a trigger signal is received, and a radio terminal device for transmitting a trigger signal, and for transmitting notice information representing own device existence based on identification information when the identification signal is received from the radio communication device. The radio terminal device includes speed measurement means for measuring own moving speed, and period setting means for setting a transmission period of a trigger signal so as to be a predetermined value on the basis of a communicable distance of the radio terminal device and the moving speed measured by the speed measurement means.