| 摘要 |
<p>A body worn transmitter (10) periodically transmits a coded rf signal from a rolling code generator (22) synchronized to produce the same random code signal for comparison. If proper coded signals are not received, a report is sent via telephone to a remote monitoring station (24). The body worn transmitter is designed to detect and defeat attempts at removal. The body worn transmitter is also used to detect the presence of a person at a particular location. By programming the time of rf transmissions, a large number of body worn transmitters can be monitored at a given location.</p> |
