RFID -A Technology Better Than Barcodes

RFID is an acronym for Radio Frequency Identification. It is a method for Data capture and Automatic Identification. RFID uses electromagnetic fields to transfer the data, for automatically identifying and tracking tags attached to the objects. RFID technology is similar to the bar code technology, but the major difference is that it uses radio waves to retrieve the data instead of using the optical scanning process for barcodes on a label.

RFID System Components

RFID Block Diagram

RFID system consists of mainly five components. They are:

  • RFID Tag,
  • Antenna
  • RFID Reader
  • Application Software
  • Communication Infrastructure

How RFID Works?

When the power supply is given to the RFID reader, first it will start to emit radio waves continuously. Now, when the RFID tag is brought within the range of the reader, the tag will start to send radio waves back to the reader. The reader then receives the waves and identifies the frequency to generate a unique ID. Reader after decoding the data encoded in the integrated circuit of tags transmits it to the PC for use. 

RFID Tag

RFID tag is a small device which stores and sends data to RFID reader. 

1. RFID Tag Elements

RFID Tag

Generally, RFID tag consists of an integrated circuit, antenna, non-volatile memory and a programmable data processor as its major components.

  • Integrated circuit: is used for the process and store of information like identification number, demodulate and modulating of RF signal and collecting DC power from the reader signal.
  • Antenna: is basically used for transmitting and receiving the reader signal.
  • Non- volatile memory: tag information is been stored safely in a non- volatile memory.
  • Programmable data processor:  is used for processing the sensed and transmitted data.
  • RFID tag also consists of a protective material which helps to hold the components together and shield them from environment conditions.

 

2. RFID Tag Types

  • Passive RFID Tags: These types of tags do not contain the power. They usually receive the power from the reader. Passive RFID tags are known popularly by the names RFID smart tags or RFID smart labels. These tags have a read range of up to 2 meters. Cost around 25 cents to few dollars.
  • Semi-Passive Tags: It uses a battery to perform the operation. Also it utilizes the power from the RFID reader inorder to transmit the signal to the reader from the tag.
  • Active Tags: These types of tags only use the battery power to do the entire operation. They have a large reading range. Cost around 50 to 250 dollars

Table 1 shows four frequency bands used in the RFID tags. The most commonly used are low frequency because they are easily readable. Higher frequencies have greater read ranges and are less sensitive to noise than the low frequency tags. RFID tags with microwave frequency do have great read ranges and higher read speeds than low frequency tags, but they require more power.

                                            RFID Frequency Range  

RFID Reader

RFID reader consists of three main components as discussed below:
 

RFID Reader

  • Antenna: Integral part of the reader which helps in receiving and transmitting signals from or to the tags.
  • Controller: It provides control of the reader system.
  • Network interface:   Once the information is received from the tag, the RFID reader will need to communicate with a controller. RS232 or RS422, Ethernet, or Wi-Fi, Bluetooth, or ZigBee can be used.

Application Software

RFID systems need application software to run the overall system. In some applications there will be a number of different reader / writers and the data to and from these needs to be coordinated and analysed. For this, application software is required. 

Communication Infrastucture

It is the network interface between the RFID reader and the controller. For communication purpose this is used.

Applications of RFID

RFID can be used in variety of applications as given below:

  • Timing Sport Events
  • Access management.
  • Track goods.
  • Airport bag tracking.
  • Track of animals and persons.
  • Payment and toll collection.
  • Machine Read Documents.
  • Smartdust.
  • Track sports to verify authenticity.

Advantages of RFID

  • RFID tags can be read from a greater distance than the barcodes.
  • RFID tags don’t need to be positioned in a line of sight with the scanner.
  • RFID tags can be read at a faster rate than barcodes;
  • RFID contain high levels of security; 
  • RFID tags carry large data capabilities 
  • RFID tags are more reusable.

Disadvantages of RFID

  • Expensive.
  • Interference.
  • Tag collision (occurs when many tags are present in a small area).
  • Reader collision occurs when the signals from two or more readers overlap.

Conclusion

While the use of RFID technology is increasing across a range of different industries, the associated security and privacy issues need to be carefully addressed. RFID advantages have made them better than the barcodes. Many applications like smart cabinets, shopping malls, road traffic signals, security purposes etc. makes use of this technology greatly.

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