| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small position detecting system with reduced power consumption. <P>SOLUTION: When a mobile station 3 enters into or leaves from an area where a unique identification signal transmitted from an infrared transmitter 1 can be received, the mobile station 3 collectively saves enter/withdraw event information and the unique identification signal at its internal memory. The mobile station 3 has a fixed period counter and collectively carries out radio transmission of a location information received for one period to a base station 4. In addition, the mobile station 3 appends the time deviation from the time of occurrence of the event, until the carrying-out of radio transmission and a self-identification code to the location information and carries out wireless transmission. The base station 4 appends a time stamp of absolute time for the time of reception to the received location information, and outputs it to a server 5. The server restores the traveling track and the transit time of the track for the mobile station 3 from the received location information. <P>COPYRIGHT: (C)2008,JPO&INPIT |
