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To: napscoordinator

These RFID signals “supposedly” only work within a certain distance from the school, so at best it would tell them that you are not at school - it won’t help them locate you.


7 posted on 11/26/2012 8:41:28 AM PST by ExTxMarine (PRAYER: It's the only HOPE for real CHANGE in America!)
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To: ExTxMarine

It would certainly help in a hostage situation within the school.


13 posted on 11/26/2012 8:57:45 AM PST by stuartcr ("When silence speaks, it speaks only to those that have already decided what they want to hear.")
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To: ExTxMarine
These RFID signals “supposedly” only work within a certain distance from the school, so at best it would tell them that you are not at school - it won’t help them locate you.

An RFID chip is basically a transponder that receives an RF signal on one frequency, converts it to dc and charges a capacitor. The capacitor is the power supply for a low power transmitter on a second frequency which responds to the inquiry pulse with a return pulse consisting of a serial number when the capacitor becomes fully charged.

This should tell you several things. Location is determined by having "readers" at fixed points, as students pass close to a reader their response codes are received and recorded. If you try to "increase range" by using a more powerful inquiry pulse you will trigger all chips at the same time and since all chips respond on the same frequency you generate a lot of noise and no information as to location.

The system can be defeated by wrapping the chip in aluminum foil when passing through a reader. If you exposed the chip to a high power pulse you may overload the capacitor power supply and render the chip silent with no visible change. A group of students with different schedules could swap cards randomly to generate bogus data. A card based system usually has a square loop of foil visible which serves as the "antenna", use a razor blade to sever the loop and the card is dead. A talented teen (forger of fake IDs) could make a facsimile of the ID w/out the chip for his friends. There are many ways for a "Good Soldier Schweik" to gum up the smooth working gears of a proto-socialistic state.

Notice that the RFID chip responds with a number stored in read only memory, not GPS coordinates. Such devices exist but are much larger than the "grain of rice" sized RFID chip, about the size of a wrist watch and they require batteries for power because they "talk back" using cell phone technology. These GPS based systems are what you want/need in cases of child snatching.

Regards,
GtG

29 posted on 11/26/2012 10:07:26 AM PST by Gandalf_The_Gray (I live in my own little world, I like it 'cuz they know me here.)
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