What are the differences between RFID and GPS? Who are major RFID vendors?

Question

Please let me know the differences between RFID and GPS and the major vendors for RFID in the world and who all are the companies are using these technologies?

Answer 1

RFID (Radio Frequency IDentification) uses very short range transmitters (range measured in meters, or less than 1 meter (~3 feet)) to interrogate RFID tags.  Transmitters are located anywhere that tags are to be interrogated such as near doors, in hand scanners, on conveyer belts, etc.  The tags contain very tiny chips that recieve the transmotter signal and respond with their ID code.  Most RFID tags operate on 125 kHz, but some operate in the VHF band.

GPS (Global Positioning System) also uses a 'transmitter' (24 of them) and receivers.  The transmitters broadcast time codes and any receiver can receive the time codes from the transmitters and calculate exactly where it is, on the earth or in the sky above the earth.  Those 24 transmitters are located in orbits around the earth in space.

I have 6 pets at home.  They have all been given an RFID tag (very tiny injectable chip under their skin).  They now each have their own unique identity that may be read by an RFID interrogator.  It is possible to build a device containing 1) an RFID interrogator 2) a GPS receiver 3) a separate small transmitter; all small enough to be placed in a box on the collar around their necks.  If any of them got lost the transmitter could broadcast their exact location with the RFID code, and a separate receiver could read that information.  Then I could go to where they are.

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Answer 2

RFID technology is mainly used to control arrivals or departure of people at work (clock in or  out), to detect if unauthorized items are leaving some premises (like at the Walmart exits) etc.

GPS is technology used to locate just about anything arround the globe that carries a GPS tranponder (reciver / emitter).

Use the Yahoo browser to get the companies that sell RFID technology. I hope this helps.