What is Radio Frequency Identification (RFID) Technology?

Introduction:

RFID technology is a widely used technology today.This technology which has its roots in WWII has various applications today ranging from tracking wildlife to identifying products in supermarkets.

The History:

Working of  IFF

RFID technology is one of the technologies that emerged due to necessities of World War II.Though RADAR technology existed during WWII there was no way to identify if an incoming aircraft was a friendly aircraft or an enemy aircraft.This led to the development of a system called Identification-Friend or Foe(IFF),to identify if the aircraft was a friendly or not.This involves a "Interrogator" on the ground sending signals to a "Transponder" on the plane.The Transponder on the plane is activated and responds by broadcasting signals back to the ground thereby identifying it as a friendly aircraft.The transponders are used by most aircraft even today.This is the predecessor to the current RFID technology.

Types of RFID:

RFID technology is based on wirelessly/remotely storing and retrieving data from miniature transponders(microchip with an antenna) called RFID tags/labels.There are three types of RFID tags-Active,Passive,Semi-Passive.Active tags require a power source and transmit a signal back to the reader/Interrogator(also with an antenna).Active tags are again classified into transponders and beacons.Transponders "wake up" only when they receive a signal from the reader thereby extending battery life.Beacons are devices which are always active and is used in Real Time Location System(RTLS) to identify and track objects within a given area.Passive tags do not require any power source and reflect back signals using the energy from the received signals.The third type of tag is called a semi-passive tag which has a built in battery which increases its range and allows it to work with weak signals. However it requires power from the incoming signals to broadcast information.This allows it to work with very weak signals and also over a greater distance.When these RFID tags receive signals from the scanner they get activated and transmit a signal back to the scanner thereby relaying the information stored on them.

Frequency Bands in which RFID operates:

Passive RFID tags can operate at low frequency,high frequency and ultra-high frequency.Low frequency tags operate at 125kHz-148kHz with 125kHz and 134.2kHz being the most commonly used.High Frequency tags operate at 13.56MHz.Ultra high frequency tags operate at 860-960Mhz with 915Mhz being the most commonly used frequency.Active tags operate at ultra high frequency(915MHz) and microwave frequency(2.45GHz).

Applications of RFID:

• In huge warehouses to identify the inventory.
• Baggage identification in airports.
• Tags are implanted in animals to track animals and provide information about them.(Example:Endangered animals,animals in a wildlife sanctuary,etc..)
• Can be used to identify lost pets.
• In retail stores to identify products through RFID tags instead of barcode scanning.
• In libraries as an alternative to barcodes on books.
• To prevent shoplifting.
• In prisons to track inmates.
• Asset tracking.
• In museums to tag objects and artifacts.
• As an access key to restricted areas.
• Active tags are used to lock and unlock vehicles.

For more real world applications view-Novel real world applications of RFID.

Privacy & Security Concerns:

The "mu chip" RFID tag manufactured by Hitachi

Passive RFID tags require no power for their working and hence can be very small in size.Due to their small size they can be concealed easily making them very hard to locate.Hence they can be used to track people or objects illegally.Also since the RFID tags can be activated without the knowledge of consumers and the data in RFID tags are not encrypted due to which the data contained in them can read without the knowledge of the consumer. Biometric passports and driver's licence which are RFID-enabled are vulnerable to identity thieves.RFID tags embedded in clothing have raised serious privacy concerns.

Conclusion-RFID at present and in the future:

RFID technology has already been adopted and is being used in various everyday tasks.RFID tags have the potential to replace and are replacing barcodes.Unlike barcodes RFID tags need be in the line of sight of the scanner/reader which reduces the time required for scanning and can reduce long queues in supermarkets proving a better experience to the shoppers.It has made inventory management in warehouses easy and has reduced the amount of manpower required.RFID tags can be directly printed onto products or packaging using semiconducting nano ink thereby reducing cost and size of tags further.The practical applications of RFID are many and the potential of this technology in the near future is astounding.If the security flaws in the technology are fixed we might see this technology being adopted more widely and being used in day to day life.