How RFID Technology Functions

One of the top complaints about shopping is the long checkout lines. These could soon be a thing of the past as traditional Universal Product Code (UPC) barcodes are replaced by smart labels, or radio frequency identification (RFID) tags. These RFID tags are advanced barcodes capable of connecting to a networked system that tracks the products you add to your shopping cart.

Picture this: you stroll through the grocery store, fill your cart, and simply walk out. No more waiting in line as each item is manually scanned. Instead, RFID tags will interact with an electronic reader that quickly identifies and registers every product in your cart. This reader is linked to a network that relays product data to retailers and manufacturers. Your bank is then notified, and the total cost is deducted from your account. No more lines, no more waiting.

Once used primarily for tracking cattle, RFID tags are now keeping tabs on consumer products across the globe. Many manufacturers rely on these tags to monitor the movement of their products from production to the moment they’re grabbed off the shelf and placed in a shopping cart.

Beyond the world of retail, RFID tags are being used to track vehicles, airline passengers, Alzheimer’s patients, and even pets. They could soon even monitor your choice between chunky or creamy peanut butter. Some critics argue that RFID technology is becoming too integrated into our lives – that is, if we’re even fully aware of the extent of its influence.

This article will introduce you to the different types of RFID tags and explain how they are tracked throughout the entire supply chain. We will also explore noncommercial applications of RFID tags, including their use by the Departments of State and Homeland Security. Finally, we’ll discuss what some critics view as an Orwellian use of RFID tags in animals, humans, and society.

Reinventing the Bar Code

Almost every item you buy from retailers has a UPC bar code printed on it. These codes help both manufacturers and retailers manage their inventory. They also provide valuable information about how many products are being purchased and, to some extent, who is buying them. These codes act as product fingerprints, consisting of machine-readable parallel bars that store binary data.

Developed in the early 1970s to streamline the checkout process, barcodes come with a few drawbacks:

RFID tags offer a significant upgrade over barcodes, as they have both read and write capabilities. The data on these tags can be modified, updated, or locked. Some retailers that have implemented RFID tags report that the technology provides a more efficient way to manage inventory and marketing strategies. With RFID, stores can track how quickly products are leaving the shelves and gain insights into which customers are purchasing them.

RFID tags won't completely replace barcodes anytime soon – there are still billions of transactions each year involving UPC scanners. However, as time progresses, we’ll definitely see more products labeled with RFID tags and a growing emphasis on seamless wireless transactions, like the convenient instant checkout system described earlier. In fact, RFID technology is already being used in payments via special credit cards and smartphones – more on that later.

Beyond retail, RFID tags are also used in transportation, such as highway toll passes and subway tickets. Thanks to their efficient data storage capabilities, RFID tags can automatically calculate tolls and fares, deducting the costs electronically from the balance on the user’s card. Instead of waiting in line at tollbooths or fumbling for change at token counters, passengers use RFID-enabled passes, similar to debit cards.

Would you trust an RFID tag with your medical history? What about your home address or the safety of your child? Let’s first explore two types of RFID tags and how they store and transmit data before we move beyond grocery store transactions to human lives.

RFID Tags: Then and Now

RFID technology has existed since 1970, but it has only recently become affordable for widespread use. Initially, RFID tags were designed to track large items like cows, railcars, and airline baggage over long distances. These early versions, known as inductively coupled RFID tags, were intricate systems involving metal coils, antennas, and glass.

Inductively coupled RFID tags were powered by a magnetic field generated by the RFID reader. Electrical current has both an electrical and a magnetic component -- it’s electromagnetic. This means that you can create a magnetic field with electricity, and conversely, generate electrical current with a magnetic field. The term "inductively coupled" comes from this process, where the magnetic field induces a current in the wire. You can learn more in How Electromagnets Work.

Capacitively coupled tags were developed as a cost-effective solution for RFID technology. These disposable tags were designed for use on cheaper products, aiming to make them as universal as barcodes. They used conductive carbon ink instead of metal coils to transmit data, with the ink being printed on paper labels and scanned by readers. Motorola's BiStatix RFID tags were pioneers in this field, featuring a silicon chip just 3 millimeters wide that could hold 96 bits of data. However, this technology did not gain traction with retailers, and BiStatix was shut down in 2001 [source: RFID Journal].

Recent advances in RFID technology include active, semi-active, and passive RFID tags. These tags can hold up to 2 kilobytes of data and consist of a microchip, an antenna, and, in the case of active and semi-passive tags, a battery. The components are typically enclosed in plastic, silicon, or sometimes glass.

At its core, every RFID tag functions in the same manner:

Inductively and capacitively coupled RFID tags have become less common today due to their cost and bulkiness. In the next section, we will dive deeper into the technologies behind active, semi-passive, and passive RFID tags.

Active, Semi-passive and Passive RFID Tags

Active, semi-passive, and passive RFID tags are driving the widespread adoption of RFID technology. These tags are more affordable to manufacture and compact enough to be placed on virtually any product.

Active and semi-passive RFID tags are powered by internal batteries that supply energy to their circuits. The active tags use their batteries to emit radio waves to communicate with readers, while semi-passive tags depend on the reader’s power to broadcast. Due to the added hardware, these tags are pricier than passive ones. Active and semi-passive tags are used for high-value items that require long-range reading, broadcasting high frequencies from 850 to 950 MHz that can be detected from 100 feet (30.5 meters) or more. With extra batteries, their range can extend beyond 300 feet (100 meters) [source: RFID Journal].

RFID tags, like other wireless technologies, transmit data within a certain portion of the electromagnetic spectrum. The exact frequency is adjustable to avoid interference with other devices or to prevent tag interference and reader interference in RFID systems. To manage wireless communication effectively, RFID systems often utilize a cellular technique known as Time Division Multiple Access (TDMA) [source: RFID Journal].

Passive RFID tags rely completely on the reader for their power. These tags can be read from a distance of up to 20 feet (6 meters) and are cheaper to produce, making them suitable for use on lower-cost merchandise. These tags are designed to be disposable, much like the consumer goods they are attached to. For example, while a railway car would carry an active RFID tag, a bottle of shampoo would be tagged with a passive one.

The cost of RFID tags is also influenced by the type of data storage they use. The three main types are read-write, read-only, and WORM (write once, read many). A read-write tag allows data to be added or modified. In contrast, read-only tags store only the initial data set and cannot be altered. WORM tags can have new data, like an additional serial number, added once but cannot be modified afterward.

Passive RFID tags typically cost between 7 and 20 cents each in the U.S. [source: RFID Journal]. Active and semi-passive tags are pricier, and manufacturers generally don't provide pricing until they know the tag's range, storage type, and quantity. The goal of the RFID industry is to bring the cost of a passive tag down to 5 cents as adoption increases among retailers.

In the following section, we'll explore how this technology could lead to the creation of a global network of RFID tags connected to the Internet.

Talking Tags

Once RFID tag prices are reduced, we will witness the rise of a widespread network of smart packages that can track every stage of the supply chain. Shelves in stores will be filled with products bearing smart labels that can be followed from the point of purchase to the trash. These shelves will communicate wirelessly with the network, with the tags being just one element in this vast product-tracking system.

The two other essential components of this network are the readers that interact with the tags, and the Internet, which will act as the communication backbone for the system.

Let’s visualize how this system could play out in a real-world example:

For this system to be effective, each product will need a unique identifier. MIT's Auto-ID Center is developing an Electronic Product Code (EPC) that could eventually replace the traditional UPC. Each smart label could hold up to 96 bits of data, including the manufacturer’s details, product name, and a 40-bit serial number. This smart label would communicate with a system known as the Object Naming Service, which retrieves product information and directs it to the manufacturer's systems.

The data on these smart labels would be encoded in Product Markup Language (PML), which is based on the eXtensible Markup Language (XML). This would enable different computer systems to communicate seamlessly, much like how Web servers interpret HTML, the standard language used to create Web pages.

While we haven't reached full implementation yet, RFID tags are already more integrated into our lives than we might think. Major retailers like Wal-Mart and Best Buy use RFID tags for inventory and marketing purposes. Automated systems, known as intelligent software agents, handle the data flowing from RFID tags, carrying out tasks such as sorting items [source: RFID Journal].

The U.S. retail industry is on the brink of adopting RFID technology on a large scale, particularly for payment systems that incorporate Near Field Communication. These systems are essentially the credit cards of the future.

Near Field Communication, Smart Phones and RFID

NFC technology holds great promise as it represents the next stage in convenient payments, offering added security. Some credit cards now feature NFC chips, allowing users to tap their cards on NFC-enabled payment terminals instead of swiping. This eliminates the risk of data being skimmed via the magnetic strip. This same system works with mobile phones as well; for a deeper understanding of how electronic payments on phones work, read more on how cellular electronic payments work.

Google is one of the key players in promoting NFC payments through Google Wallet. This app securely stores credit card details and allows for easy tap-to-pay transactions at NFC-enabled terminals. However, the technology's utility depends on the availability of NFC terminals in retail spaces and the number of phones supporting it. Initially, Google Wallet was only compatible with the Android Nexus S smartphone.

So, how does this relate to RFID? NFC devices are capable of reading passive RFID tags and retrieving the information stored within them. This capability is already being incorporated into modern advertising. Imagine a typical mall poster advertising a pair of jeans. By embedding an RFID tag, advertisers can create "smart" posters that offer more interactive customer experiences. For instance, tapping an NFC-enabled phone on such a poster could provide you with a 10% discount coupon for those jeans at Macy's. The affordability of passive RFID tags makes them ideal for promotional uses that engage consumers.

Both NFC and RFID technologies are poised for significant growth in the retail sector, but concerns about security persist. Some critics are uneasy about the potential for retailers to track and record individual purchases. However, the use of RFID isn't limited to retail; in the next section, we’ll explore how the government is adopting RFID technology.

Government-issued RFIDs

While many consumers unknowingly or happily buy products tracked by RFID tags, there is a growing backlash regarding U.S. government legislation that mandates embedding RFID microchips in passports.

On August 14, 2006, the U.S. Department of State started issuing electronic passports, also known as e-passports. The initiative followed the terrorist attacks of September 11, 2001, with the Department of Homeland Security (DHS) proposing the e-passport as a safety measure to enhance air travel security, strengthen border control, and streamline customs procedures at U.S. airports. The e-passport's advanced security features — including a chip identification number, digital signature, and a photograph functioning as a biometric identifier — make it nearly impossible to counterfeit.

While the e-passport will certainly improve security, its extensive storage of personal information has sparked concerns about its potential for identity theft. Two possible forms of identity theft related to e-passports are:

Nevertheless, the DHS maintains that the e-passport is completely safe to use, assuring the public that the necessary precautions have been implemented to safeguard user privacy.

The e-passport is priced at $97. While this may seem expensive, the costs associated with installing RFID readers at airports are even higher. Transitioning to e-passports will require a gradual shift, but authorities are already discussing future upgrades, such as enhanced security features and improved biometrics for the next generation of e-passports.

While the conversation surrounding e-passports is significant, it is minor in comparison to the debates surrounding human microchipping. Up next, we will explore how RFID microchips are being used in living organisms.

Animal and Human Chipping

Animal chipping is far from a novel concept — farmers have been using RFID technology to track livestock for years. However, businesses are now turning pet chipping into a lucrative industry, and some companies are even offering human chipping options.

RFID pet recovery systems use tiny microchips, about the size of a grain of rice, which contain the pet owner's contact details and sometimes the animal’s medical information. Veterinarians can scan these chips in lost pets to identify their owners. However, issues arise as there are many competing pet recovery systems, each using different microchips. The Humane Society of the United States has called for the development of a universal RFID reader to ensure all microchips, regardless of manufacturer or model year, can be read by any veterinarian. In November 2005, President George Bush signed legislation aimed at standardizing pet microchips and creating a national database of pet owner information [source: RFID Journal].

Although the FDA approved the use of RFID microchips in animals and humans in 2004, research dating back to 1996 suggests that these implants could cause cancerous tumors in lab rats and mice [source: Washington Post]. Specifically, these implants led to the development of sarcomas, which affect body tissues. No conclusive studies have been conducted to determine if similar cancers can form in animals beyond lab rats and mice, and it is still too soon to assess their potential effects on humans. Despite this, there have been no proven negative health impacts from the radio waves emitted by RFID chips. However, some concerns about the drawbacks of human chipping may outweigh its benefits.

VeriChip Corp. is at the forefront of the human chipping industry. The company produces microchips with unique identification numbers that link to a VeriChip medical database, containing emergency contact information and medical histories. Individuals with serious health issues like Alzheimer's disease are ideal candidates for the VeriChip. Aside from a one-time implantation fee, VeriChip charges annual fees depending on the amount of information stored in the database — you can opt for just basic details like your name and contact information, or choose to include your entire medical history. However, VeriChip is still in its early stages of expansion, meaning RFID readers aren't available in all hospitals, and doctors may not routinely check patients for chips, which could render the VeriChip ineffective in certain cases.

One successful application of VeriChip technology is the Hugs Infant Protection Program. In this RFID-based system, newborns in select hospital nurseries are fitted with ankle bracelets containing RFID chips. If anyone attempts to remove a baby without authorization, alarms will go off both at the nurses' station and at the exit doors. You can learn more about how this system prevents infant abductions on the VeriChip website.

Next, we will explore the concerns voiced by critics of RFID technology and its use in tracking devices in today's world.

RFID Criticism

Like many emerging technologies, RFID sparks fear and skepticism due to a lack of understanding. These fears, some valid, have led to heated debates, with unlikely allies such as the American Civil Liberties Union and the Christian Coalition finding common ground on the issue.

The stakes are much higher when it comes to human chipping compared to merchandise tagging, and critics worry that mandatory chipping may become a reality. The controversy reached new heights in 2006 when CityWatcher.com implanted RFID chips in two of its employees. The company maintained that the employees voluntarily chose to undergo the procedure for easier access to secure vaults where confidential documents were stored. Other employees opted out of the chip implants, and their positions remained unaffected.

Beyond the technical limitations of VeriChip scanning discussed earlier, the implantation of RFID chips in humans raises serious religious and civil liberty concerns for some individuals. For those with religious objections, human chipping is seen as a fulfillment of the biblical prophecy in the Book of Revelation, with the chip symbolizing the 'Mark of the Beast.' For others, particularly those concerned with civil liberties, the technology feels like a step towards an Orwellian future where every thought and action is monitored by an all-powerful entity.

While we have the choice of whether or not to implant RFID chips in ourselves or our pets, we lack similar control over the tags placed on the commercial products we purchase. In the book 'Spychips: How Major Corporations and Government Plan to Track Your Every Move with RFID,' authors Katherine Albrecht and Liz McIntyre highlight the extreme potential of RFID tags. They warn that RFID could be used to monitor our purchasing habits and bank accounts, setting prices for products based on these factors. While this might sound paranoid, hackers have shown that RFID tags can be manipulated, including deactivating anti-theft measures and altering prices. Stronger encryption is necessary to prevent hackers from intercepting these signals using highly sensitive antennae.

Critics further argue that relying heavily on RFID for security could lead to complacency at human security checkpoints. If security personnel become too dependent on RFID-based anti-theft devices and government-issued identification, they may overlook criminal activities happening right before them, rendering the technology ineffective as a primary security tool.