Activation of tracking device
1 Assignment
0 Petitions
Accused Products
Abstract
A tracking device obtains container position information, which is communicated wirelessly to a remote site. It is determined if the container is in proximity to an aircraft by detection of electromagnetic fields, and if so, the communication is disabled. Re-enabling of the communication is allowed if simultaneously no electromagnetic fields are detected and the tracking device is able to determine a container position. Re-enabling is also allowed if the lack of characteristic electromagnetic fields has lasted for a time period exceeding a predetermined value. This predetermined value is preferably larger than a maximum flight time from a globally most remote flight position. Alternatively, the predetermined value is larger than a maximum flight time on battery backup. The positioning information is preferably performed using GPS positioning. The detection comprises detection of electromagnetic field frequencies in the range of 400 Hz.
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Citations
28 Claims
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1-14. -14. (canceled)
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15. Method for operating a tracking device operatively connected to a container and having at a remote communication device, comprising the steps of:
performing a positioning information obtaining procedure concerning said container;
sensing whether said tracking device is in proximity to an aircraft;
said step of sensing in turn comprising the step of detecting electromagnetic fields emitted by said aircraft;
disabling emission of radio frequency signals from said remote communication device if proximity to an aircraft is indicated in said step of sensing; and
re-enabling emission of radio frequency signals from said remote communication device if lack of proximity to an aircraft is indicated in said step of sensing simultaneously as said step of performing a positioning information obtaining procedure is successful.- View Dependent Claims (16, 17, 18, 19, 20)
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21. Tracking device for remote monitoring of a container to which said tracking device is operatively connected, said tracking device comprising:
positioning system to obtain positioning information concerning said container;
remote communication device;
control system connected to said positioning system and said remote communication device; and
detector for sensing whether said tracking device is in proximity to an aircraft, said detector being connected to said control system;
said detector comprising an electromagnetic field sensor, sensing electromagnetic fields emitted by said aircraft;
said control system being arranged to disable emission of radio frequency signals from said remote communication device responsive to an output of said detector indicating proximity to an aircraft, said control system being arranged to re-enable emission of radio frequency signals from said remote communication device responsive to a lack of an output of said detector indicating proximity to an aircraft simultaneously as said positioning system being able to obtain positioning information.- View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. Container for airfreight, having tracking device for remote monitoring of said container, said tracking device comprising:
positioning system to obtain positioning information concerning said container;
remote communication device;
control system connected to said positioning system and said remote communication device; and
detector for sensing whether said container is in proximity to an aircraft, said detector being connected to said control system;
said detector comprising an electromagnetic field sensor, sensing electromagnetic fields emitted by said aircraft;
said control system being arranged to disable emission of radio frequency signals from said remote communication device responsive to an output of said detector indicating proximity to an aircraft;
said control system being arranged to re-enable emission of radio frequency signals from said remote communication device responsive to a lack of an output of said detector indicating proximity to an aircraft simultaneously as said positioning system being able to obtain positioning information.
Specification