| 摘要 |
<p>The car position finder is an integrated system allowing a car itinerary to be followed over several days. Electronic units are stored in each car and transmit GSM or DCS 1800 standard radio signals. The signals carry identification messages held in chip cards in each unit. The messages are passed across the mobile telephone network, and the digital information passed to a server. A computer at the server location logs the time and identifies the car position. A portable telephone can then be used by police to access the information.</p> |
