Talking Tags

When the RFID industry is able to lower the price of tags, it will lead to a ubiquitous network of smart packages that track every phase of the supply chain. Store ­shelves will be full of smart-labeled products that can be tracked from purchase to trash can. The shelves themselves will communicate wirelessly with the network. The tags will be just one component of this large product-tracking network.

The other two pieces to this network will be the readers that communicate with the tags and the Internet, which will provide communications lines for the network.

Let's look at a real-world scenario of this system:

• At the grocery store, you buy a carton of milk. The milk containers will have an RFID tag that stores the milk's expiration date and price. When you lift the milk from the shelf, the shelf may display the milk's specific expiration date, or the information could be wirelessly sent to your personal digital assistant or cell phone.
  
• As you exit the store, you pass through doors with an embedded tag reader. This reader tabulates the cost of all the items in your shopping cart and sends the grocery bill to your bank, which deducts the amount from your account. Product manufacturers know that you've bought their product, and the store's computers know exactly how many of each product need to be reordered.
  
• Once you get home, you put your milk in the refrigerator, which is also equipped with a tag reader. This smart refrigerator is capable of tracking all of the groceries stored in it. It can track the foods you use, how often you restock your refrigerator and can let you know when that milk and other foods spoil.
  
• Products are also tracked when they are thrown into a trash can or recycle bin. At this point, your refrigerator could add milk to your grocery list, or you could program the fridge to order these items automatically.
  
• Based on the products you buy, your grocery store gets to know your unique preferences. Instead of receiving generic newsletters with weekly grocery specials, you might receive one created just for you. If you have two school-age children and a puppy, your grocery store can use customer-specific marketing by sending you coupons for items like juice boxes and dog food.

In order for this system to work, each product will be given a unique product number. MIT's Auto-ID Center is working on an Electronic Product Code (EPC) identifier that could replace the UPC. Every smart label could contain 96 bits of information, including the product manufacturer, product name and a 40-bit serial number. Using this system, a smart label would communicate with a network called the Object Naming Service. This database would retrieve information about a product and then direct information to the manufacturer's computers.

The information stored on the smart labels would be written in a Product Markup Language (PML), which is based on the eXtensible Markup Language (XML). PML would allow all computers to communicate with any computer system similar to the way that Web servers read Hyper Text Markup Language (HTML), the common language used to create Web pages.

We're not at this point yet, but RFID tags are more prominent in your life than you may realize. Wal-Mart and Best Buy are just two major merchandisers that use RFID tags for stocking and marketing purposes.

Some critics find the idea of merchandisers tracking and recording purchases to be alarming. But retail isn't the only industry using RFID technology. In the next section, we'll learn how the government is putting RFID tags to use.­

How RFID Works

RFID Tags Past and Present

RFID technology has been around since 1970, but until recently, it has been too expensive to use on a large scale. Originally, RFID tags were used to track large items, like cows, railroad cars and airline luggage, that were shipped over long distances, These original tags, called inductively coupled RFID tags, were complex systems of metal coils, antennae and glass.

Inductively coupled RFID tags were powered by a magnetic field generated by the RFID reader. Electrical current has an electrical component and a magnetic component -- it is electromagnetic. Because of this, you can create a magnetic field with electricity, and you can create electrical current with a magnetic field. The name "inductively coupled" comes from this process -- the magnetic field inducts a current in the wire. You can learn more in How Electromagnets Work.

Capacitively coupled tags

were created next in an attempt to lower the technology's cost. These were meant to be disposable tags that could be applied to less expensive merchandise and made as universal as bar codes. Capacitively coupled tags used conductive carbon ink instead of metal coils to transmit data. The ink was printed on paper labels and scanned by readers. Motorola's BiStatix RFID tags were the frontrunners in this technology. They used a silicon chip that was only 3mm wide and stored 96 bits of information. This technology didn't catch on with retailers, and BiStatix was shut down in 2001 [source: RFID Journal].

Newer innovations in the RFID industry include active, semi-active, and passive RFID tags. These tags can store up to 2 kilobytes of data and are composed of a microchip, antenna, and, in the case of active and semi-passive tags, a battery. The tag's components are enclosed within plastic, silicon or sometimes glass.

At a basic level, each tag works in the same way:

• Data­ stored within an RFID tag's microchip waits to be read.
  
  
• The tag's antenna receives electromagnetic energy from an RFID reader's antenna.
  
  
• Using power from its internal battery or power harvested from the reader's electromagnetic field, the tag sends radio waves back to the reader.
  
  
• ­The reader picks up the tag's radio waves and interprets the frequencies as meaningful data.
  

Inductively coupled and capacitively coupled RFID tags aren't used as commonly today because they are expensive and bulky. In the next section, we'll learn more about active, semi-passive and passive RFID tags.

Reinventing the Bar Code

Reinventing the Bar Code

Almost everything that you buy from retailers has a UPC bar code printed on it. These bar codes help manufacturers and retailers keep track of inventory. They also give valuable ­information about the quantity of products being bought and, to some extent, by whom the products are being bought. These codes serve as product fingerprints made of machine-readable parallel bars that store binary code.

Created in the early 1970s to speed up the check out process, bar codes have a few disadvantages:

• In order to keep up with inventories, companies must scan each bar code on every box of a particular product.
  
  
• Going through the checkout line involves the same process of scanning each bar code on each item.
  
  
• Bar code is a read-only technology, meaning that it cannot send out any information.

RFID tags are an improvement over bar codes because the tags have read and write capabilities. Data stored on RFID tags can be changed, updated and locked. Some stores that have begun using RFID tags have found that the technology offers a better way to track merchandise for stocking and marketing purposes. Through RFID tags, stores can see how quickly the products leave the shelves and who's buying them.

In addition to retail merchandise, RFID tags have also been added to transportation devices like highway toll passcards and subway passes. Because of their ability to store data so efficiently, RFID tags can tabulate the cost of tolls and fares and deduct the cost electronically from the amount of money that the user places on the card. Rather than waiting to pay a toll at a tollbooth or shelling out coins at a token counter, passengers use RFID chip-embedded passes like debit cards.

But would you entrust your medical history to an RFID tag? How about your home address or your baby's safety? Let's look at two types of RFID tags and how they store and transmit data before we move past grocery store purchase­s to human lives.

How RFID Works

Long checkout lines at the grocery store are one of the biggest complaints about the shopping experience. Soon, these lines could disappear when the ubiquitous Universal Product Code (UPC) bar code is replaced by smart labels, also called radio frequency identification (RFID) tags. RFID tags are intelligent bar codes that can talk to a networked system to track every product that you put in your shopping cart.

Imagine going to the grocery store, filling up your cart and walking right out the door. No longer will you have to wait as someone rings up each item in your cart one at a time. Instead, these RFID tags will communicate with an electronic reader that will detect every item in the cart and ring each up almost instantly. The reader will be connected to a large network that will send information on your products to the retailer and product manufacturers. Your bank will then be notified and the amount of the bill will be deducted from your account. No lines, no waiting.

RFID tags, a technology once limited to tracking cattle, are tracking consumer products worldwide. Many manufacturers use the tags to track the location of each product they make from the time it's made until it's pulled off the shelf and tossed in a shopping cart.

Outside the realm of retail merchandise, RFID tags are tracking vehicles, airline passengers, Alzheimer's patients and pets. Soon, they may even track your preference for chunky or creamy peanut butter. Some critics say RFID technology is becoming too much a part of our lives -- that is, if we're even aware of all the parts of our lives that it affects.

In this article, you'll learn about the types of RFID tags and how these tags can be tracked through the entire supply chain. We'll also look at the non-commercial uses of RFID tags and how the Departments of State and Homeland Security are using them. Lastly, we'll examine what some critics consider an Orwellian application of RFID tags in animals, humans and our society.

What is RFID?

Short for radio frequency identification, RFID is a dedicated short range communication (DSRC) technology. The term RFID is used to describe various technologies that use radio waves to automatically identify people or objects. RFID technology is similar to the bar code identification systems we see in retail stores everyday; however one big difference between RFID and bar code technology is that RFID does not rely on the line-of-sight reading that bar code scanning requires

The Technology Behind RFID
With RFID, the electromagnetic or electrostatic coupling in the RF (radio frequency) portion of the electromagnetic spectrum is used to transmit signals. An RFID system consists of an antenna and a transceiver, which read the radio frequency and transfer the information to a processing device (reader) and a transponder, or RF tag, which contains the RF circuitry and information to be transmitted. The antenna provides the means for the integrated circuit to transmit its information to the reader that converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can analyze the data.

In RFID systems, the tags that hold the data are broken down into two different types. Passive tags use the radio frequency from the reader to transmit their signal. Passive tags will generally have their data permanently burned into the tag when it is made, although some can be rewritten.

Active tags are much more sophisticated and have on-board battery for power to transmit their data signal over a greater distance and power random access memory (RAM) giving them the ability to store up to 32,000 bytes of data.

RFID Frequencies
Much like tuning in to your favorite radio station, RFID tags and readers must be tuned into the same frequency to enable communications. RFID systems can use a variety of frequencies to communicate, but because radio waves work and act differently at different frequencies, a frequency for a specific RFID system is often dependant on its application. High frequency RFID systems (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) offer transmission ranges of more than 90 feet, although wavelengths in the 2.4 GHz range are absorbed by water, which includes the human body, and therefore has limitations.

Common Uses of RFID
RFID systems can be used just about anywhere, from clothing tags to missiles to pet tags to food - anywhere that a unique identification system is needed. The tag can carry information as simple as a pet owners name and address or the cleaning instruction on a sweater to as complex as instructions on how to assemble a car.

Here are a few examples of how RFID technology is being used in everyday places:

• RFID systems are being used in some hospitals to track a patient's location, and to provide real-time tracking of the location of doctors and nurses in the hospital. In addition, the system can be used to track the whereabouts of expensive and critical equipment, and even to control access to drugs, pediatrics, and other areas of the hospital that are considered "restricted access" areas.
  
  
  
• RFID chips for animals are extremely small devices injected via syringe under skin. Under a government initiative to control rabies, all Portuguese dogs must be RFID tagged by 2007. When scanned the tag can provide information relevant to the dog's history and its owner's information.
  
  
  
• RFID in retail stores offer real-time inventory tracking that allows companies to monitor and control inventory supply at all times.
  
  
  
• The Orlando/Orange County Expressway Authority (OOCEA) is using an RFID based traffic-monitoring system, which uses roadside RFID readers to collect signals from transponders that are installed in about 1 million E-Pass and SunPass customer vehicles.

The Future of RFID
RFID is said by many in the industry to be the frontrunner technology for automatic identification and data collection. The biggest, as of yet unproven, benefit would ultimately be in the consumer goods supply chain where an RFID tag attached to a consumer product could be tracked from manufacturing to the retail store right to the consumer's home.

Many see RFID as a technology in its infancy with an untapped potential. While we may talk of its existence and the amazing ways in which this technology can be put to use, until there are more standards set within the industry and the cost of RFID technology comes down we won't see RFID systems reaching near their full potential anytime soon.