LOCATION DETECTION SYSTEM, TRANSMISSION DEVICE, SERVER, AND RADIO SIGNAL COLLISION AVOIDANCE METHOD IN THE SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce an electric power consumption of tags while avoiding collisions of radio signals.

SOLUTION: By shifting a transmission time by inserting a stand-by time inherent to a tag (TG) between the reception of a first radio signal and the transmission of a second radio signal, or by transmitting the second radio signal to a server with information on the measurement on the field strength of the first radio signal by the tag and the short setting of the stand-by time when the field strength is small, the server (SV) computes the stand-by time on the basis of a code indicated by the second radio signal received from the tag. Collisions may be avoided by the insertion of a signal in the first radio signal, the reading of its information by the tag, and determination as to whether to transit the second radio signal or not according to rules.

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