RFID is an automated data-capture technology that can be used to electronically identify, track, and store information about groups of products, individual items, or product components. The technology consists of three key pieces: RFID tags; RFID readers; and a data collection, distribution, and management system. RFID tags are small or miniaturized computer chips programmed with the information about a product or with anumber that corresponds to information that is stored in a database. The tags can be located inside or on the surface of the product, item, or packing material. RFID readers are querying systems that interrogate or send signals to the tags and receive the responses. These responses can be stored within the reader for later transfer to a data collection system or instantaneously transferred to the data collection system. Lastly, data collection systems consist of computers running data processing software, which typically are networked with a larger information management system.
Overview of the operation of RFID
RFID relies on radio frequency communication. The RFID reader emits energy, in the form of a radio wave at a particular frequency, which is used to power and to communicate with the RFID tags. As the radio waves propagate through the environment, their energy gradually dissipates – so a tag that is beyond a certain distance from the RFID reader will not be able to pick up enough signal to operate reliably. In other words, the maximum operating distance between the RFID reader and a tag (also known as the range) is limited. The exact range depends on a great many factors, includ¬ing the radio frequency being used for communication, the power emitted by the RFID reader, sources of radio interference and objects in the environment that are likely to reflect or absorb radio waves. A typical range for a passive RFID system will be anywhere between a few centimetres and a few metres.
Since the communication mechanism is based on radio wave propagation, a direct ‘line of sight’ between the reader and the tag is not required. (Contrast this with barcode systems where the reader must be able to ‘see’ the barcode label.) This means that tagged objects may be identified even if the tag or even the entire object is not in direct view of the reader – for example they may be inside packaging or hidden behind other objects. Also, most modern RFID systems can identify multiple tags in very quick suc¬cession (from tens to hundreds per second). This means that many tagged objects can be read in effect ‘simultaneously’ as they pass by an RFID reader, something that is not easily achievable with other technologies such as barcodes. Although the relative ori¬entation of the tag and the reader does alter the operating range to some extent, it is often possible to set up an RFID system so that this effect is not important – in other words, tagged objects may pass by a reader with little constraint on their orientation or alignment, another big advantage over many other identification technologies.
RFID Works in different frequencies and standards
- LF (Low Frequency)
- HF (High Frequency)
- UHF (Ultra High Frequency)
| 120–150 kHz (LF)
|| 10 cm
| 13.56 MHz (HF)
|| ISM Band
|| 10 cm to 1 m
| 860 - 960 MHz
|| ISM Band
|| 1 m to 12 m
Benefits of RFID technology
The RFID system allows manufacturers, retailers, and suppliers to efficiently collect, manage, distribute, and store information on inventory, business processes, and security controls. RFID will allow: retailers to identify potential delays and shortages; grocery stores to eliminate or reduce item spoilage; toll systems to identify and collect auto tolls on roadways; suppliers to track shipments; and in the case of critical materials, RFID will allow receiving authorities to verify the security and authentication of shipped items. These uses are seen as only the beginning, and as RFID is deployed across different sectors and services, increasing efficiency and visibility, several other applications and benefits may arise. The technology itself offers several improvements over its predecessor technologies – the barcode and magnetic stripe cards. The central data feature of RFID technology is the Electronic Product Code (EPC), which is viewed by many in the industry as the next-generation barcode or Universal Product Code (UPC). This EPC code can carry moredata, than the UPC code and can be reprogrammed with new information if necessary. Like the UPC, the EPC code consists of a series of numbers that identify the manufacturer and product type. The EPC code also includes an extra set of digits to identify unique items.