RADIO FREQUENCY IDENTIFICATION (RFID)

RFID:

RFID can be defined in the following manner

RFID is the wireless non-contact use of radio-frequency electromagnetic fields to transfer data, for the purpose of automatically identifying and tracking tags attached to objects.

Also RFID can be defined as

RFID is an automatic identification method using radio waves.

An RFID tag is a device that can store and transmit data to a reader in a contact less manner using radio waves. It means that a RFID tag does not need any contact to transmit data to a reader with the help of radio waves.Unlike a barcode, the tag does not need to be within line of sight of the reader and may be embedded in the tracked object.

APPLICATIONS OF RFID:

RFID can be used in a variety of applications such as:

Access management Tracking of goods Tracking of persons and animals Toll collection and contactless payment Machine readable travel documents Smart dust (for massively distributed sensor networks) Tracking sports memorabilia to verify authenticity Airport baggage tracking logistics

RFID FREQUENCY BANDS:

RFID frequency bands

Band Regulations Range Data speed Remarks

Approximate tag cost

in volume (2006) US $

120–150 kHz (LF) Unregulated 10 cm LowAnimal identification, factory data collection

$1

13.56 MHz (HF)ISM band worldwide

1 mLow to moderate

Smart cards (MIFARE, ISO/IEC 14443)

$0.50

433 MHz (UHF)Short Range Devices

1–100 m

ModerateDefense applications, with active tags

$5

865-868 MHz (Europe)902-928 MHz (North America) UHF

ISM band 1–2 mModerate to high

EAN, various standards$0.15 (passive tags)

2450-5800 MHz (microwave)

ISM band 1–2 m High802.11 WLAN, Bluetooth standards

$25 (active tags)

3.1–10 GHz (microwave) Ultra wide band to 200 High requires semi-active or active $5 projected

M tags

The above table clearly explains the frequency ranges, the band regulations, data speed, applications of particular frequency band and the cost of the tag.

A radio-frequency identification system uses tags, or labels attached to the objects to be identified. Two-way radio transmitter-receivers called interrogators or readers send a signal to the tag and read its response. The readers generally transmit their observations to a computer system running RFID software or RFID middleware.

RFID systems typically come in three configurations. One is a Passive Reader Active Tag (PRAT) system that has a passive reader which only receives radio signals from active tags (battery operated, transmit only). The reception range of a PRAT system reader can be adjusted from 1-2,000 feet. Thereby allowing for great flexibility in applications such as asset protection and supervision. Another configuration is an Active Reader Passive Tag (ARPT) system that has an active reader, which transmits interrogator signals and also receives authentication replies from passive tags. Finally, there is the Active Reader Active Tag (ARAT) system in which active tags are awoken with an interrogator signal from the active reader. A variation of this system could also use a Battery Assisted Passive (BAP) tag which acts like a passive tag but has a small battery to power the tag's return reporting signal.

Tags may either be read-only, having a factory-assigned serial number that is used as a key into a database, or may be read/write, where object-specific data can be written into the tag by the system user. Field programmable tags may be writing-once, read-multiple; "blank" tags may be written with an electronic product code by the user.

The tag's information is stored electronically in a non-volatile memory. The RFID tag includes a small RF transmitter and receiver. An RFID reader transmits an encoded radio signal to interrogate the tag. The tag receives the message and responds with its identification information. This may be only a unique tag serial number, or may be product-related information such as a stock number, lot or batch number, production date, or other specific information.

RFID tags contain at least two parts: an integrated circuit for storing and processing information, modulating and demodulating a radio-frequency (RF) signal, collecting DC power from the incident reader signal, and other specialized functions; and antenna for receiving and transmitting the signal.

ADANTAGES:

* The read only tag code data is 100% secure and cannot be changed or duplicated.

*Tags are available in a great range of types, sizes and materials.

*No need for physical contact between the data carrier and the communication device.

*The tags can be used repeatedly

*Relatively low maintenance cost.

*Extremely low error rate.

*RFID technology is a labor-saving technology. This translates to cost savings.

RFID vs. Barcodes Comparison:

RFID and barcodes are similar in that they are both data collection technologies, meaning they automate the process of collecting data. However, they also differ significantly in many areas. Although this comparison primarily focuses on the advantages of RFID over barcodes, RFID will not completely replace barcode technology. Barcodes offer some advantages over RFID, most notably their low cost.

COMPARISION STATISTICS:

RFID is 15-20 times faster than manual and barcode processes for inventorying IT assets.

Some companies experience a 95% reduction in time using RFID

The #1 RFID application being deployed is IT asset tracking

FUTURE SCOPE

The world will be very different once readers and RFID tags are everywhere. In an RFID enhanced future, the benefits would assure not just to business, but also to consumers. If the usage of RFID tags increases it will be very beneficial in several aspects. Also the readers need to find many applications in several fields.