Acquisition of position information is indispensable to navigation. Latitude and longitude information can be obtained by global positioning systems (GPS), which, however, cannot be used under ground. The resolution of position information service using personal handy-phone system (PHS) is quite low. To overcome these problems, here the authors propose a novel position related information acquisition system through the use of IC labels and mobile data communications, which consists of IC label, personal digital assistants (PDA), server and database. The PDA functions as an IC label reader and communicates with the server. The information contents of the IC label is not position information itself but a position ID. The position ID read by the PDA is uplink-transmitted to the server using mobile data communications. The position ID is used as the address of the lookup table type database. Therefore, arbitrary not-yet-used position ID can be allotted to an IC label posted at an arbitrary place. The contents of database corresponding to a particular position ID may be latitude, longitude, altitude, URL, floor number, etc., which are downlink-transmitted to PDA.
Abstract