Radio-frequency identification (RFID) is the use of a wireless non-contact system that uses radio-frequency electromagnetic fields to transfer data from a tag attached to an object, for the purposes of automatic identification and tracking. Some tags require no battery and are powered by the electromagnetic fields used to read them. Others use a local power source and emit radio waves (electromagnetic radiation at radio frequencies). The tag contains electronically stored information which can be read from up to several metres (yards) away. Unlike a bar code, the tag does not need to be within line of sight of the reader and may be embedded in the tracked object.
RFID tags are used in many industries. An RFID tag attached to an automobile during production can be used to track its progress through the assembly line. Pharmaceuticals can be tracked through warehouses. Livestock and pets may have tags injected, allowing positive identification of the animal. RFID identity cards can give employees access to locked areas of a building, and RF transponders mounted in automobiles can be used to bill motorists for access to toll roads or parking.
Since RFID tags can be attached to clothing, possessions, or even implanted within people, the possibility of reading personally-linked information without consent has raised privacy concerns.
Applications
The RFID tag can be affixed to an object and used to track and manage inventory, assets, people, etc. For example, it can be affixed to cars, computer equipment, books, mobile phones, etc.
In social media, RFID is being used to tie the physical world with the virtual world. RFID in Social Media first came to light in 2010 with Facebook's annual conference.
RFID offers advantages over manual systems or use of bar codes. The tag can be read if passed near a reader, even if it is covered by the object or not visible. The tag can be read inside a case, carton, box or other container, and unlike barcodes RFID tags can be read hundreds at a time. Bar codes can only be read one at a time.
In 2011, the cost of passive tags started at US$0.05 each; special tags, meant to be mounted on metal or withstand gamma sterilization, can go up to US$5. Active tags for tracking containers, medical assets, or monitoring environmental conditions in data centers start at US$50 and can go up over US$100 each. Battery Assisted Passive (BAP) tags are in the US$3–10 range and also have sensor capability like temperature and humidity.
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
- Smartdust (for massively distributed sensor networks)
- Tracking sports memorabilia to verify authenticity
- Airport baggage tracking logistics
Applications:
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 middle ware.
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 can be either passive, active or battery assisted passive. An active tag has an on-board battery that periodically transmits its ID signal. A battery assisted passive (BAP) has a small battery on board that is activated when in the presence of a RFID reader. A passive tag is cheaper and smaller because it has no battery. Instead, the tag uses the radio energy transmitted by the reader as its energy source. The interrogator must be close for RF field to be strong enough to transfer sufficient power to the tag. Since tags have individual serial numbers, the RFID system design can discriminate several tags that might be within the range of the RFID reader and read them simultaneously.
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 write-once, read-multiple; "blank" tags may be written with an electronic product code by the user.
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 an antenna for receiving and transmitting the signal.
Fixed readers are set up to create a specific interrogation zone which can be tightly controlled. This allows a highly defined reading area for when tags go in and out of the interrogation zone. Mobile readers may be hand-held or mounted on carts or vehicles.
| Data speed | Remarks | Approximate tag cost in volume (2006) US $ | |||
|---|---|---|---|---|---|
| 120–150 kHz (LF) | Unregulated | 10 cm | Low | Animal identification, factory data collection | $1 US |
| 13.56 MHz (HF) | ISM band worldwide | 1 m | Low to moderate | Smart cards | $0.50 |
| 433 MHz (UHF) | Short Range Devices | 1–100 m | Moderate | Defence applications, with active tags | $5 |
| 868-870 MHz (Europe) 902-928 MHz (North America) UHF | ISM band | 1–2 m | Moderate to high | EAN, various standards | $0.15 (passive tags) |
| 2450-5800 MHz (microwave) | ISM band | 1–2 m | High | 802.11 WLAN, Bluetooth standards | $25 (active tags) |
| 3.1–10 GHz (microwave) | Ultra wide band | to 200 M | High | requires semi-active or active tags | $5 projected |
Signaling between the reader and the tag is done in several different incompatible ways, depending on the frequency band used by the tag. Tags operating on LF and HF frequencies are, in terms of radio wavelength, very close to the reader antenna, less than one wavelength away. In this near field region, the tag is closely coupled electrically with the transmitter in the reader. The tag can modulate the field produced by the reader by changing the electrical loading the tag represents. By switching between lower and higher relative loads, the tag produces a change that the reader can detect. At UHF and higher frequencies, the tag is more than one radio wavelength from the reader. The tag can backscatter a signal. Active tags may contain functionally separated transmitters and receivers, and the tag need not respond on a frequency related to the reader's interrogation signal.[7]
An Electronic Product Code (EPC) is one common type of data stored in a tag. When written into the tag by an RFID printer, the tag contains a 96-bit string of data. The first eight bits are a header which identifies the version of the protocol. The next 28 bits identify the organization that manages the data for this tag; the organization number is assigned by the EPCGlobal consortium. The next 24 bits are an object class, identifying the kind of product; the last 36 bits are a unique serial number for a particular tag. These last two fields are set by the organization that issued the tag. Rather like a URL, the total electronic product code number can be used as a key into a global database to uniquely identify a particular product.
Often more than one tag will respond to a tag reader, for example, many individual products with tags may be shipped in a common box or on a common pallet. Collision detection is important to allow reading of data. Two different types of protocols are used to "singulate" a particular tag, allowing its data to be read in the midst of many similar tags. In a slotted Aloha system, the reader broadcasts an initialization command and a parameter that the tags individually use to pseudo-randomly delay their responses. When using an "adaptive binary tree" protocol, the reader sends an intialization symbol and then transmits one bit of ID data at a time; only tags with matching bits respond, and eventually only one tag matches the complete ID string
History and technology background
In 1945 Léon Theremin invented an espionage tool for the Soviet Union which retransmitted incident radio waves with audio information. Sound waves vibrated a diaphragm which slightly altered the shape of the resonator, which modulated the reflected radio frequency. Even though this device was acovert listening device, not an identification tag, it is considered to be a predecessor of RFID technology, because it was likewise passive, being energized and activated by waves from an outside source.
Similar technology, such as the IFF transponder developed in the United Kingdom, was routinely used by the allies in World War II to identify aircraft as friend or foe. Transponders are still used by most powered aircraft to this day. Another early work exploring RFID is the landmark 1948 paper by Harry Stockman, titled "Communication by Means of Reflected Power" (Proceedings of the IRE, pp 1196–1204, October 1948). Stockman predicted that "... considerable research and development work has to be done before the remaining basic problems in reflected-power communication are solved, and before the field of useful applications is explored."
Mario Cardullo's device, patented on January 23, 1973, was the first true ancestor of modern RFID, as it was a passive radio transponder with memory.The initial device was passive, powered by the interrogating signal, and was demonstrated in 1971 to the New York Port Authority and other potential users and consisted of a transponder with 16 bit memory for use as a toll device. The basic Cardullo patent covers the use of RF, sound and light as transmission media. The original business plan presented to investors in 1969 showed uses in transportation (automotive vehicle identification, automatic toll system, electronic license plate, electronic manifest, vehicle routing, vehicle performance monitoring), banking (electronic check book, electronic credit card), security (personnel identification, automatic gates, surveillance) and medical (identification, patient history).
An early demonstration of reflected power (modulated backscatter) RFID tags, both passive and semi-passive, was performed by Steven Depp, Alfred Koelle, and Robert Freyman at the Los Alamos National Laboratory in 1973.[13] The portable system operated at 915 MHz and used 12-bit tags. This technique is used by the majority of today's UHFID and microwave RFID tags.
The first patent to be associated with the abbreviation RFID was granted to Charles Walton in 1983.
[edit]Miniaturization
RFIDs are easy to conceal or incorporate in other items. For example, in 2009 researchers at Bristol University successfully glued RFID micro-transponders to live ants in order to study their behavior. This trend towards increasingly miniaturized RFIDs is likely to continue as technology advances.
Hitachi holds the record for the smallest RFID chip, at 0.05mm × 0.05mm. This is 1/64th the size of the previous record holder, the mu-chip. Manufacture is enabled by using the silicon-on-insulator (SOI) process. These dust-sized chips can store 38-digit numbers using 128-bit Read Only Memory (ROM).A major challenge is the attachment of the antennas, thus limiting read range to only millimeters.
[edit]Current uses
In 2010 three key factors drove a significant increase in RFID usage: decreased cost of equipment and tags, increased performance to a reliability of 99.9% and a stable international standard around UHF passive RFID. The adoption of these standards were driven by EPCglobal, a joint venture between GS1 and GS1 US, which were responsible for driving global adoption of the barcode in the 1970s and 1980s. The EPCglobal Network was developed by the Auto-ID Center, an academic research project headquartered at the Massachusetts Institute of Technology (MIT) with labs at five leading research universities around the globe: Cambridge, Adelaide, Keio, Shanghai, Fudan, St. Gallen. At RFID Journal Live 2010 in Orlando, Airbus detailed 16 active projects, IBMand—most recently added to the team—CSC. The two other areas of significant use are financial services for IT asset tracking and healthcare. RFID is becoming increasingly prevalent as the price of the technology decreases.
[edit]Commerce
[edit]Payment by mobile phones
Since summer 2009, two credit card companies have been working with Dallas, Texas-based DeviceFidelity to develop specialized microSD cards. When inserted into a mobile phone, the microSD card can be both a passive tag and an RFID reader. After inserting the microSD, a user's phone can be linked to bank accounts and used in mobile payment.
Dairy Queen in conjunction with Vivotech has also begun using RFIDs on mobile phones as part of their new loyalty and rewards program.Patrons can ask to receive an RFID tag to place on their phone. After activation, the phone can receive promotions and coupons, which can be read by ViVOtech's specialized NFC devices.
Similarly, 7-Eleven has been working alongside MasterCard to promote a new touch-free payment system. Those joining the trial are given a complimentary Nokia 3220 cell phone – after activation, it can be used as an RFID-capable MasterCard credit card at any of 7-Eleven's worldwide chains.
Nokia's 2008 device, the 6212, has RFID capabilities also. Credit card information can be stored, and bank accounts can be directly accessed using the enabled handset. The phone, if used as a vector for mobile payment, has added security in that users would be required to enter a passcode or PIN before payment is authorized.
[edit]Asset management
RFID combined with mobile computing and Web technologies provide a way for organizations to identify and manage their assets. Mobile computers, with integrated RFID readers, can now deliver a complete set of tools that eliminate paperwork, give proof of identification and attendance. This approach eliminates manual data entry.
Web based management tools allow organizations to monitor their assets and make management decisions from anywhere in the world. Web based applications now mean that third parties, such as manufacturers and contractors can be granted access to update asset data, including for example, inspection history and transfer documentation online ensuring that the end user always has accurate, real-time data. Organizations are already using RFID tags combined with a mobile asset management solution to record and monitor the location of their assets, their current status, and whether they have been maintained.
RFID is being adopted for item-level retail uses. Aside from efficiency and product availability gains, the system offers a superior form of electronic article surveillance (EAS), and a superior self checkout process for consumers. The first commercial, public item-level RFID retail system installation is believed to be in May 2005 by Freedom Shopping, Inc. in North Carolina, USA.
2009 witnessed the beginning of wide-scale asset tracking with passive RFID. Wells Fargo and Bank of America made announcements that they would track every item in their data centers using passive RFID. Most of the leading banks have since followed suit. The Financial Services Technology Consortium(FSTC) set a technical standard for tagging IT assets and other industries have used that standard as a guideline. For instance the US State Department is now tagging IT assets with passive RFID using the ISO/IEC 18000-6 standard.
[edit]Inventory systems
An advanced automatic identification technology based on RFID technology has significant value for inventory systems. The system can provide accurate knowledge of the current inventory. In an academic study performed at Wal-Mart, RFID reduced Out-of-Stocks by 30 percent for products selling between 0.1 and 15 units a day. Other benefits of using RFID include the reduction of labor costs, the simplification of business processes, and the reduction of inventory inaccuracies.
In 2004, Boeing integrated the use of RFID technology to help reduce maintenance and inventory costs on the Boeing 787 Dreamliner. With the high costs of aircraft parts, RFID technology allowed Boeing to keep track of inventory despite the unique sizes, shapes and environmental concerns. During the first six months after integration, the company was able to save $29,000 in labor.
In 2007, Recall Corporation integrated the use of RFID to help organizations track and audit their records, to support compliance with regulations such as the Sarbanes-Oxley Act and HIPAA.
[edit]Product tracking
RFID use in product tracking applications begins with plant-based production processes, and then extends into post-sales configuration management policies for large buyers.
In 2005, the Wynn Casino, Las Vegas, began placing individual RFID tags on high value chips. These tags allowed casinos the ability to detect counterfeit chips, track betting habits of individual players, speed up chip tallies, and determine counting mistakes of dealers. In 2010, the Bellagio casino was robbed of $1.5 million in chips. The RFID tags of these chips were immediately invalidated, thus making the cash value of these chips $0.
RFID can also be used for supply chain management in the fashion industry. The RFID label is attached at the garment at production, can be read/traced througout the entire supply chain and is removed at the point of sale (POS).
[edit]Access control
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 HighFID tag. In Feb 2008, Emirates Airline started a trial of RFID baggage tracing at London and Dubai airports.
[edit]Promotion tracking
To prevent retailers diverting products, manufacturers are exploring the use of RFID tags on promoted merchandise so that they can track exactly which product has sold through the supply chain at fully discounted prices.
[edit]Advertising
When customers enter a dressing room, the mirror reflects their image and also images of the apparel item being worn by celebrities on an interactive display. A webcam also projects an image of the consumer wearing the item on the website for everyone to see. This creates an interaction between the consumers inside the store and their social network outside the store. The technology in this system is an RFID interrogator antenna in the dressing room and Electronic Product Code RFID tags on the apparel item.
[edit]Transportation and logistics
Logistics and transportation are major areas of implementation for RFID technology. Yard management, shipping and freight and distribution centers use RFID tracking technology. In the railroadindusry, RFID tags mounted on locomotives and rolling stock identify the owner, identification number and type of equipment and its characteristics. This can be used with a database to identify the lading, origin, destination, etc. of the commodities being carried.
In commercial aviation, RFID technology is being incorporated to support maintenance on commercial aircraft. RFID tags are used to identify baggage and cargo at several airports and airlines.
Some countries are using RFID technology for vehicle registration and enforcement.RFID can help detect and retrieve stolen cars.
[edit]Passports
The first RFID passports ("E-passport") 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 (time, date, and place) of entries and exits from the country.
Other countries that insert RFID in passports include Norway (2005), Japan (March 1, 2006), most EU countries (around 2006) including Spain, Ireland and the UK, Australia, Hong Kong and the United States (2007), Serbia (July 2008), Republic of Korea (August 2008), Taiwan (December 2008), Albania (January 2009), The Philippines (August 2009), Republic of Macedonia (2010).
Standards for RFID passports are determined by the International Civil Aviation Organization (ICAO), and are contained in ICAO Document 9303, Part 1, Volumes 1 and 2 (6th edition, 2006). ICAO refers to the ISO/IEC 14443 RFID chips in e-passports as "contactless integrated circuits". ICAO standards provide for e-passports to be identifiable by a standard e-passport logo on the front cover.
Since 2006, RFID tags included in new US passports will store the same information that is printed within the passport and also include a digital picture of the owner. The US State Departmentinitially stated the chips could only be read from a distance of 10 cm (4 in), but after widespread criticism and a clear demonstration that special equipment can read the test passports from 10 meters (33 ft) away, the passports were designed to incorporate a thin metal lining to make it more difficult for unauthorized readers to "skim" information when the passport is closed. The department will also implement Basic Access Control (BAC), which functions as a Personal Identification Number (PIN) in the form of characters printed on the passport data page. Before a passport's tag can be read, this PIN must be entered into an RFID reader. The BAC also enables the encryption of any communication between the chip and interrogator.
[edit]Transportation payments
In many countries, RFID tags can be used to pay for mass transit fares on bus, trains, or subways, or to collect tolls on highways.
Some bike lockers are operated with RFID cards assigned to individual users. A prepaid card is required to open or enter a facility or locker and is used to track and charge based on how long the bike is parked.
The Zipcar car-sharing service uses RFID cards for locking and unlocking cars and for member identification.
In Singapore, RFID replaces paper Season Parking Ticket (SPT).
