RFID - Radio Frequency Identification

RFID Bracelets at Coachella (2012)
RFID Bracelets at Coachella (2012). Gabriel Olsen / Getty Images

Definition: RFID - Radio Frequency Identification - is a system for tagging and identifying portable equipment, consumer products, and even living organisms (like pets and people). Using a special device called an RFID reader, RFID allows objects to be labeled and tracked as they move from place to place.

Uses of RFID

RFID tags are used for tracking of expensive industrial and healthcare equipment, medical supplies, library books, cattle, and vehicles.

 Other notable uses of RFID include wristbands for public events and the Disney MagicBand. Note that some credit cards began using RFID in the mid 2000s but this generally been phased out in favor of EMV.

How RFID Works

RFID works using small (sometimes smaller than a fingernail) pieces of hardware called RFID chips or RFID tags. These chips feature an antenna to transmit and receive radio signals. Chips (tags) may be attached to, or sometimes injected into, target objects.

Whenever a reader within range sends appropriate signals to an object, the associated RFID chip responds by sending whatever data it contains. The reader, in turn, displays these response data to an operator. Readers may also forward data to a networked central computer system.

RFID systems operate in any of four radio frequency ranges:

  • 125 to 134.2 kHz
  • 13.56 MHz
  • 856 MHz to 960 MHz
  • 2.45 GHz

The reach of an RFID reader varies depending on the radio frequency in use and also physical obstructions between it and the chips being read, from a few inches (cm) up to hundreds of feet (m).

Higher frequency signals generally reach shorter distances.

So-called active RFID chips include a battery while passive RFID chips do not. Batteries help the RFID tag scan over longer distances but also significantly increase its cost. Most tags work in the passive mode where chips absorb the radio signals incoming from the reader and turn them into energy sufficient to send back responses.

RFID systems support writing information onto the chips as well as simply reading data.

The Difference Between RFID and Barcodes

RFID systems were created as an alternative to barcodes. Relative to barcodes, RFID allows objects to be scanned from a greater distance, supports storing of additional data on the target chip, and generally allows more information to be tracked per object. For example, RFID chips attached to food packaging may also list information like the product's expiration date and nutrition information and not just the price like a typical barcode.

NFC vs. RFID

Near-field communication (NFC) is an extension of RFID technology band being developed to support mobile payments. NFC utilizes the 13.56 MHz band.

Issues with RFID

Unauthorized parties can intercept RFID signals and read tag information if within range and using the right equipment, an especially serious concern for NFC. RFID has also raised some privacy concerns given its ability to track the movement of people equipped with tags.

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