RFID Technology
By CXOtoday Staff
Jun 22, 2007 1630 hrs IST

Radio Frequency Identification (RFID) is a generic term that is used to describe a system that transmits the identity (in the form of a unique serial number) of an object or person wirelessly, using radio waves. It's grouped under the broad category of Automatic Identification (auto-ID) technologies. Auto-ID technologies include bar codes, optical character readers, and some biometric technologies, such as retinal scans. The auto-ID technologies have been used to reduce the amount of time and labor needed to input data manually and to improve data accuracy. RFID is an automatic identification method, relying on storing and remotely retrieving data using RFID tags or transponders. An RFID tag is an object that can be attached to or incorporated into a product for the purpose of identification using radio waves. Most RFID tags contain at least 2 parts. One is an integrated circuit for storing and processing information, modulating, and demodulating a Radio Frequency (RF) signal, and perhaps other specialized functions. The second is an antenna for receiving and transmitting the signal. An emerging technology called chipless RFID allows for discrete identification of tags without an integrated circuit, thereby allowing tags to be printed directly onto assets at lower cost than traditional tags. For example, information about a product or shipment date of manufacture, destination, and sell-by date can be written to a tag. To retrieve the data stored on an RFID tag, a reader is required. A typical reader is a device that has one or more antenna that emits radio waves and receives signals back from the tag. The reader then passes the information in digital form to a computer system. The RFID tag can automatically be read from a centimeter away, and does not have to be in the line of sight of the reader. The current thrust in RFID use is in the supply chain management for large enterprises. RFID increases the speed and accuracy with which inventory can be tracked and managed thereby saving money for the business. Until recently, the cost of RFID has limited its use. For many applications, such as tracking parts for just-in-time manufacturing, companies could justify the cost of tags a dollar or more per tag by the savings an RFID system could generate. When RFID was used to track assets or reusable containers within a company s own premises, the tags could be reused. Classification of RFID tags Passive Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming radio frequency signal provides just enough power for the CMOS integrated circuit in the tag to power up and transmit a response. Most passive tags signal by backscattering the carrier wave from the reader. The response of a passive RFID tag is not necessarily just an ID number; the tag chip can contain non-volatile EEPROM for storing data. These tags have almost unlimited applications in consumer goods and other areas. Active Active RFID tags have their own internal power source, which is used to power the integrated circuits and broadcast the signal to the reader. Active tags are typically much more reliable due to the ability for active tags to conduct a "session" with a reader. Active tags, due to their onboard power supply, also transmit at higher power levels, allowing them to be more effective in "RF challenged" environments like water, metals, or at longer distances. Many active tags have practical ranges of hundreds of meters, and a battery life of up to 10 years. Some active RFID tags include sensors such as temperature logging which have been used in concrete maturity monitoring or to monitor the temperature of perishable goods. Other sensors that have been married with active RFID include humidity, shock/vibration, light, radiation, temperature, and atmospherics like ethylene. Active tags typically have much longer range (approximately 100 m/300 feet) and larger memories, as well as the ability to store additional information sent by the transceiver. The United States Department of Defense has successfully used active tags to reduce logistics costs and improve supply a chain visibility for more than 15 years. Semi-passive Semi-passive tags are similar to active tags as they have their own power source, but the battery is used just to power the microchip and not broadcast a signal. The RF energy is reflected back to the reader like a passive tag. Current uses Passports RFID tags are being used in passports issued by many countries. The first RFID passports ("e-passports") were issued by Malaysia in 1998. In addition to information also contained on the visual data page of the passport, Malaysian e-passports record the travel history of entries and exits from the country. RFID tags are included in United Kingdom and some United States passports, beginning in 2006. The US produced 10 million passports in 2005, and it has been estimated that 13 million will be produced in 2006. The chips will store the same information that is printed within the passport, and will also include a digital picture of the owner. The passports will incorporate a thin metal lining to make it more difficult for unauthorized readers to "skim" information when the passport is closed. Transport payments Collect tolls in high-traffic areas from active RFID units in vehicles. Traffic into crowded areas is regulated by variable tolls imposed using an active tagging system combined with the use of stored-value cards. The design is embedded in a credit card-like pass, that, when scanned, reveals details of whether the pass is valid, and for how long the pass will remain valid. Product tracking RFID tags are used in library book or bookstore tracking, pallet tracking, building access control, airline baggage tracking, and apparel and pharmaceutical item tracking. High-frequency tags are widely used in identification badges, replacing earlier magnetic stripe cards. These badges need only be held within a certain distance of the reader to authenticate the holder. The American Express Blue credit card now includes a high-frequency RFID tag. Automotive Microwave RFID tags are used in long range access control for vehicles. Since the 1990s RFID tags have been used in car keys. Without the correct RFID, the car will not start. RFID in inventory systems An advanced automatic identification technology such as the Auto-ID system based on the RFID technology has two values for inventory systems. First, the visibility provided by this technology allows an accurate knowledge on the inventory level by eliminating the discrepancy between inventory record and physical inventory. Second, the RFID technology can prevent or reduce the sources of errors. Benefits of using RFID include the reduction of labor costs, the simplification of business processes, and the reduction of inventory inaccuracies. Potential uses Replacing barcodes RFID tags are often envisioned as a replacement for UPC or EAN barcodes, having a number of important advantages over the older barcode technology. They may not ever completely replace barcodes, due in part to their higher cost, and in other part to the advantage of more than one independent data source on the same object. The storage of data associated with tracking items will require many terabytes on all levels. Filtering and categorizing RFID data is needed in order to create useful information. The unique identity in any case is a mandatory requirement for RFID tags, despite special choice of the numbering scheme. The uniqueness of RFID tags means that a product may be individually tracked as it moves from location to location, finally ending up in the consumer's hands. This may help companies to combat theft and other forms of product loss. Moreover, the tracing back of products is an important feature that gets well supported with RFID tags containing, not just a unique identity of the tag, but also the serial number of the object. It has also been proposed to use RFID for Point of Sale (POS) store checkout to replace the cashier with an automatic system, which needs no barcode scanning. Telemetry Active RFID tags also have the potential to function as low-cost remote sensors that broadcast telemetry back to a base station. Applications of tagometry data could include sensing of road conditions by implanted beacons, weather reports, and noise level monitoring. Patient identification In July 2004, the Food and Drug Administration issued a ruling that essentially begins a final review process that will determine whether hospitals can use RFID systems to identify patients and/or permit relevant hospital staff to access medical records. Since then, a number of U.S. hospitals have begun implanting patients with RFID tags and using RFID systems, more generally, for workflow and inventory management. The future scenario The significant advantage of all types of RFID systems is the non-contact, non-line-of-sight nature of the technology. Tags can be read through a variety of substances such as snow, fog, ice, paint, crusted grime, and other visually and environmentally challenging conditions, where barcodes or other optically read technologies would be useless. RFID tags can also be read in challenging circumstances at remarkable speeds, in most cases responding in less than 100 milliseconds. The read/write capability of an active RFID system is also a significant advantage in interactive applications such as work-in-process or maintenance tracking. Though it is a costlier technology (compared with barcode), RFID has become indispensable for a wide range of automated data collection and identification applications. Developments in RFID technology continue to yield larger memory capacities, wider reading ranges, and faster processing. It is highly unlikely that the technology will ultimately replace barcode -even with the inevitable reduction in raw materials coupled with economies of scale, the integrated circuit in an RF tag will never be as cost-effective as a barcode label. However, RFID will continue to grow in its established niches where barcode or other optical technologies are not effective. If some standards commonality is achieved - whereby RFID equipment from different manufacturers can be used interchangeably - the market will grow exponentially. As told to Priyanka Akhouri