1. Radio frequency identification (RFID)

• Radio frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data.

• The data is stored on and retrieved from RFID tags.

• The tag contains a transponder with a digital memory chip that is given a unique electronic product code.

• The data is written onto the memory and read from it.

• An RFID antenna packaged with a transceiver and decoder emits a signal activating the RFID tag so it can read and write data to the tag.

• When an RFID tag passes through the electromagnetic zone, it detects the reader’s activation signal. The reader decodes the code ID of the tag and the data encoded in the tag’s integrated circuit (silicon chip).

• In this way, an RFID tag is an information source. The data written onto it can be retrieved whenever needed or it can be transmitted to different RFID readers.

• RFID is also called dedicated short range communication(DSRC).

2. RFID components and their characteristics

i. Tags

• Tags can be active (with watch-sized battery) or passive (without battery). Passive tags take power from the RF field of the interrogating antenna.
• The size of the tag varies from less than 1 square inch to many square inches.
• The size is dependent on power and frequency (13.56 MHz, 433 MHz, 900 MHz, 2.4 GHz with power from 1 mW to 1 W)
• Memory can be read only, write one and read many with 1 byte to 512 Kilo-bytes storage.

ii. Reader

• The reader receives data, validates it and even writes data onto the tag through RFID antenna.

iii. Host data management software applications

• The data read from the tag can be passed to the host computer.
• The application software on the host processes the data, and may perform various filtering operations to reduce the numerous often redundant reads of the same tag to a smaller and more useful data set.

3. RFID Features:

The following are the key features of RFID:

• No line-of-sight: To read or write RFID tags doesn’t require line of sight.

• Robust: Because RFID systems do not need to be visible, they can be encased within rugged material protecting them from the environment in which they are being used. This means they can be used in harsh fluid and chemical environments and rough handling situations.

• Read speed: Tags can be read from significant distances and can also be read very quickly - for example, on a conveyor.

• Reading multiple items: A number of tagged items can be read at the same time within an RF field. This cannot be done easily with visual identifiers.

• Security: Because tags can be enclosed, they are much more difficult to tamper with. A number of tag types now also come programmed with a unique identifier (serial identification) which is guaranteed to be unique throughout the world.

• Programmability: Many tags are read/write capable, rather than read only. This means that information can be written to the tag.

4. RFID Applications:

i. Automotive:

• Auto makers have added security and convenience to automobiles by using RFID technology for anti-theft immobilizers and passive entry systems.
• Some auto manufacturers use RFID systems to move cars through an assembly line. At each successive stage of production, the RFID tag tells the computers what the next step of the automated assembly is.

ii. Animal tracking:

• Ranchers and livestock producers use RFID technology to meet export regulations and optimize livestock value.
• Wild animals are tracked in ecological studies, and many pets who are tagged are returned to their owners.
• Thus a tag can carry information as simple as a pet owner’s name and address.

iii. Assets tracking:

• Hospitals and pharmacies meet tough product accountability legislation with RFID; libraries limit theft and keep books in circulation more efficiently.

iv. Contactless commerce:

• Blue-chip companies such as American Express, Exxon Mobile, and MasterCard use innovative form factors enabled by RFID technology to strengthen brand loyalty and boost revenue per customer.

v. Supply chain:

• Wal-Mart, Target, Best Buy, and other retailers have discovered that RFID technology can keep inventories at the optimal level, reduce out of stock losses, limit shoplifting, and speed customers through check-out lines.

vi. Replacement for bar codes:

• RFID can serve a lot of advantages by replacing bar codes.
• One of the key differences between RFID and bar code technology is RFID eliminates the need of line-of-sight reading that bar coding depends on.
• Also, RFID scanning can be done at greater distances than bar code scanning. High frequency RFID systems (850–950 MHz, 2.4–2.5 GHz) offer transmission ranges more than 90 feet.
• Barcodes are fixed at the time of printing and can be rendered useless by defacement or smudging.
• Bar codes can be spoofed or easily defeated by any malicious individual having a laser printer at their disposal.