| 摘要 |
A separation alarm, comprising a mobile telecommunication device (1) and a tag (2); the mobile telecommunication device comprising: a receiver (10), which is able to receive signals transmitted by the tag (2); a range calculator (12), which is able to determine, from the signals received from the tag (2), the range of the tag (2) from the mobile telecommunication device (1) to generate a range signal, and compare the range to a predetermined range limit; and an alarm device (4, 6), arranged to emit an alarm on instruction by the range calculator (12); the tag (2) comprising a transmitter (7) arranged to transmit signals to the mobile telecommunication device (1); in which the range calculator (12) is arranged to cause the alarm device (4, 6) to emit an alarm should the range indicated by the range signal exceed the range limit. Typically, the mobile telecommunications device (1) or the tag (2) is arranged to capture and optionally store, as part of the alarm being emitted, sound or video occurring in its vicinity.
|
