| 摘要 |
PROBLEM TO BE SOLVED: To prevent communication failure caused by interference to be generated when a plurality of mobile stations are simultaneously present at the place to perform position detection by oscillating position signals from sign posts arranged at suitable intervals within the moving range of mobile station and receiving the position signals from the sign posts to the mobile station. SOLUTION: A host 1 is connected through a network 2 to a plurality of access points 3. Sign posts 4 report information showing their install positions through a radio data communication means having a narrow communication area to a mobile station 5. The mobile station 5 stores information showing the execution of position detection as a history and transmits its own user ID and the information of position detection due to the passed sign posts 4 through a radio communicating means having a wide communication area to the closet access point 3. By providing such radio communicating means, the precise position detection of mobile stations is performed and at the same time, the opportunity to perform communication between the host 1 equipped with the monitoring device and the mobile station 5 can be increased. |
