| 摘要 |
<p>A positioning system includes a transmitter which transmits first unique information from a predetermined installation position and a mobile terminal which receives the first unique information transmitted from the transmitter. According to the first unique information received by the mobile terminal, the position of the mobile terminal is estimated. If a transmitter having forged first unique information is generated, a false position is accepted. Thus, there is a problem that a position information service unique to a predetermined position can be provided to a user not at a valid position. In order to solve the problem, a terminal transmits to a server, first unique information received by the terminal as information unique to the transmitter and a reference (second unique information) to decide whether the first unique information is from a valid transmitter installed at a valid position. The server derives information (third unique information) unique to the installation position of the transmitter from the received first unique information and compares the third unique information to the second unique information received from the terminal. If these are in a predetermined relationship, it is judged that the transmitter is at a valid position.</p> |
