What is RFID?

I hear a lot about RFID. What is it really?

RFID technology is used to replace traditional barcode systems and Electronic Article Security (EAS) systems where barcode is utilised for item identification and EAS for item surveillance or security. Presently most major supermarkets will use barcode for inventory control and also for Self Service. Barcode technology is inexpensive and it works well using EAS technology for security. The problem is that security gates will only alarm with sensitised tag devices, but the item that triggered the alarm cannot be easily identified.

The RFID device is a very small radio transponder set into a larger antenna surface which operates in set frequency ranges. Within the transponder chip is a tiny amount of memory which generally stores a unique identification number and other relevant information. The radio transponder transmits this information to the reader device when it is queried.

There are three main RFID frequencies: 125khz, 13.56Mhz and 900Mhz, with each frequency giving differing speed and range. The 125khz low frequency (LF) range is used in proximity applications, like door security, and is now known by a recently coined phrase Near Field Communication (NFC) with many mobile devices now being equipped with the reader technology. The 13.56Mhz high frequency (HF) range has been in use for many years in library style applications. Today we primarily use the 900Mhz ultra high frequency (UHF) range as EPC Global's Gen 2 technology is the fastest growing RFID technology. UHF RFID has more reader and tag manufacturers than the other types and it is faster with a greater operating range.

The following is a representation of the various technologies.

RFID vs. Barcode

  • The RFID device serves the same purpose as a barcode as it provides a unique identifier for the item. Just as a barcode or magnetic strip must be scanned to get the information, the RFID device must be scanned to retrieve the identifying information.
  • RFID can work in conjunction with barcode technology, but where barcode requires line of sight and can be scanned only one at a time, RFID does not require line of sight and many can be read at one time.
  • The barcode is an identifier which can be easily replicated, thus it cannot be used as a security device, RFID can provide both identification and serialization which provides security.