Abstract: An acquisition unit determines the location of an object. A setting unit sets a wait time if the determined location satisfies predetermined conditions. The range of wait time that the setting unit can set is narrower than the range of wait time that can be set by other kinds of terminal devices capable of broadcasting packet signals by means of carrier sensing. A carrier sense unit performs a carrier sense over the set wait time. A modulator-demodulator unit and RF unit broadcast a packet signal together with the results of the carrier sense.

Abstract: A modem unit receives a signal broadcasted by a base station apparatus. A storage unit extracts information included in the received signal and stores the extracted information. A detection unit detects a fact that the signal broadcasted by the base station apparatus is not received. A generation unit measures a period of time starting when the storage unit has stored the information. When the detection unit detects the fact and when the measured period of time is shorter than a threshold, the generation unit broadcasts a signal including the information stored in the storage unit.

Abstract: An acquisition unit determines the location of an object. A setting unit sets a wait time if the determined location satisfies predetermined conditions. The range of wait time that the setting unit can set is narrower than the range of wait time that can be set by other kinds of terminal devices capable of broadcasting packet signals by means of carrier sensing. A carrier sense unit performs a carrier sense over the set wait time. A modulator-demodulator unit and RF unit broadcast a packet signal together with the results of the carrier sense.