| 摘要 |
<p>A Communication System (10) comprising of five inter-related modules that work together : a Location Module (12), a Communication Module (14), a Power Module (16), an Antena Module (18) and a Processor Module (20) for tracking an asset globally accesses multiple communication networks and switches among them, choosing the most economic, available communication mode without Hie need for a constant power supply. An intergrated motion sensor uses a combination of GPS updating and dynamic movement calculation to obtain the most reliable position estimation. Current location is identified within a small radius at all times. While taking advantage of the GPS system to obtain accurate location information, direct exposure to GPS satellites is not required al all times. The system obtains position information from GPS satellites whenever valid signals are not accessible. The position accuracy of the device is preferably within a 20-meter radius from the exact location.</p> |
