Proximity cards and RFID cards offer a diverse range of functions, while providing a great deal of convenience, as the cards must simply be waived or tapped in front of a reader rather than swiped. These cards are commonly used for such applications as access control, time and attendance, network login security, biometric verification, cashless payment, and event management.

Instead of contact pads, contactless smart cards use an embedded antenna that is attached to the chip to transfer information stored in the chip's memory to a remote computer. New information is written into the chip in the same way. Contactless cards do not have to be inserted into a card acceptor device. Instead, they need only be passed within range of a radio frequency acceptor to read and store information in the chip. The range of operation is typically from about 2.5" to 3.9" (63.5mm to 99.06mm) depending on the acceptor.

Proximity Cards

Proximity cards or simply "prox cards", like contactless smart cards, communicate through an embedded antenna to a remote receiver. Unlike smart cards, prox cards are read-only devices. It is not possible to write information back on to the card's chip. Prox cards also generally have a greater range of operation than smart cards - from 2.5" to 20" (63.5mm to 508mm), depending on the reader. The amount of information prox cards store is relatively small; an example might be identification codes verified by remote computers to allow access.

Prox cards are available with ISO thicknesses from .027" to .033" (.6858mm to .8382mm) and also as "clamshell" cards from .060" to over .070" thick (1.524mm to over 1.778mm).

Prox cards continue to grow in popularity because of the convenience they offer in security, identification, and access control applications - especially door access, where fast, hands-free operation is preferred.

Hybrid Cards

Hybrid cards is the term given to e-cards that contain two or more embedded chip technologies such as a contactless smart chip with its antenna, a contact smart chip with its contact pads, and/or a proximity chip with its antenna -- all in a single card. The contactless chip is typically used for applications demanding fast transaction times, like mass transit. The contact chip can be used in applications requiring higher levels of security. The individual electronic components are not connected to each other even though they share space in a single card.

Hybrid cards offer a unique solution for updating your existing badging system. This e-card allows you to accommodate the infrastructure and card technology of a legacy system while adding new applications and e-card technologies -- all in a single ID card.

Combi Cards

The combi card -- also known as a dual-interface card -- has one smart chip embedded in the card that can be accessed through either contact pads or an embedded antenna. This form of smart card is growing in popularity because it provides ease-of-use and high security in a single card product.

Mass transit is expected to be one of the more popular applications for the combi card. In the mass transit application, a contact-type acceptor can be used to place a cash value in the chip's memory and the contactless interface can be used to deduct a fare from the card.

What is automatic identification?

Automatic identification, or auto ID for short, is the broad term given to a host of technologies that are used to help machines identify objects. Auto identification is often coupled with automatic data capture. That is, companies want to identify items, capture information about them and somehow get the data into a computer without having employees type it in. The aim of most auto-ID systems is to increase efficiency, reduce data entry errors and free up staff to perform more value-added functions, such as providing customer service. There is a host of technologies that fall under the auto-ID umbrella. These include bar codes, smart cards, voice recognition, some biometric technologies (retinal scans, for instance), optical character recognition (OCR) and radio frequency identification (RFID).

What is RFID?

Radio frequency identification, or RFID, is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID tag). The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it.

Is RFID better than using bar codes?

RFID is not necessarily "better" than bar codes. The two are different technologies and have different applications, which sometimes overlap. The big difference between the two is bar codes are line-of-sight technology. That is, a scanner has to "see" the bar code to read it, which means people usually have to orient the bar code toward a scanner for it to be read. Radio frequency identification, by contrast, doesn't require line of sight. RFID tags can be read as long as they are within range of a reader. Bar codes have other shortcomings as well. If a label is ripped or soiled or has fallen off, there is no way to scan the item, and standard bar codes identify only the manufacturer and product, not the unique item. The bar code on one milk carton is the same as every other, making it impossible to identify which one might pass its expiration date first.

Will RFID replace bar codes?

It's very unlikely. Bar codes are inexpensive and effective for certain tasks, but RFID and bar codes will coexist for many years.

Is RFID new?

RFID is a proven technology that's been around since at least the 1970s. Up to now, it's been too expensive and too limited to be practical for many commercial applications. But if tags can be made cheaply enough, they can solve many of the problems associated with bar codes. Radio waves travel through most non-metallic materials, so they can be embedded in packaging or encased in protective plastic for weatherproofing and greater durability. And tags have microchips that can store a unique serial number for every product manufactured around the world.

If RFID has been around so long and is so great, why aren't all companies using it?

Many companies have invested in RFID to get the advantages it offers. These investments are usually made in closed-loop systems—that is, when a company is tracking goods that never leave its own control. That's because some existing RFID systems use proprietary technology, which means that if company A puts an RFID tag on a product, it can't be read by Company B unless they both use the same RFID system from the same vendor. Another reason is the price. If a company tracks assets within its own four walls, it can reuse the tags over and over again, which is cost-effective. But for a system to work in an open supply chain, it has to be cheap because the company that puts the tag on a case or pallet is unlikely to be able to reuse it.

What has prevented RFID from taking off until now?

One issue is standards. There are well-developed standards for low- and high-frequency RFID systems, but most companies want to use UHF in the supply chain because it offers longer read range—up to 20 feet under good conditions. UHF technology is relatively new, and standards weren't established until recently. Another issue is cost. RFID readers typically cost $1,000 or more. Companies would need thousands of readers to cover all their factories, warehouses and stores. RFID tags are also fairly expensive—20 cents or more—which makes them impractical for identifying millions of items that cost only a few dollars.

Are any companies using RFID today?

Yes. Thousands of companies around the world use RFID today to improve internal efficiencies. Club Car, a maker of golf carts uses RFID to improve efficiency on its production line. Paramount Farms—one of the world's largest suppliers of pistachios—uses RFID to manage its harvest more efficiently. NYK Logistics uses RFID to improve the throughput of containers at its busy Long Beach, Calif., distribution center. And many other companies are using RFID for a wide variety of applications.

What are some of the most common applications for RFID?

RFID is used for everything from tracking cows and pets to triggering equipment down oil wells. It may sound trite, but the applications are limited only by people's imagination. The most common applications are payment systems (Mobil Speedpass and toll collection systems, for instance), access control and asset tracking. Increasingly, companies are looking to use RFID to track goods within their supply chain, to work in process and for other applications. To read more about RFID on a grand scale, check out TransLink® smart card, where transit riders can travel seamlessly throughout the Bay Area.

Where will the initial benefits of RFID technology be?

RFID technology can deliver benefits in many areas, from tracking work in process to speeding up throughput in a warehouse. As the technology becomes standardized, it will be used more and more to track goods in the supply chain. The aim is to reduce administrative error, labor costs associated with scanning bar codes, internal theft, errors in shipping goods and overall inventory levels.

How does an RFID system work?

An RFID system consists of a tag made up of a microchip with an antenna, and an interrogator or reader with an antenna. The reader sends out electromagnetic waves. The tag antenna is tuned to receive these waves. A passive RFID tag draws power from the field created by the reader and uses it to power the microchip's circuits. The chip then modulates the waves that the tag sends back to the reader, which converts the new waves into digital data. For more information on the components of a complete system used in businesses, see Getting Started.

What is the difference between low-, high-, and ultra-high frequencies?

Just as your radio tunes in to different frequencies to hear different channels, RFID tags and readers have to be tuned to the same frequency to communicate. RFID systems use many different frequencies, but generally the most common are low-frequency (around 125 KHz), high-frequency (13.56 MHz) and ultra-high-frequency or UHF (860-960 MHz). Microwave (2.45 GHz) is also used in some applications. Radio waves behave differently at different frequencies, so you have to choose the right frequency for the right application.

How do I know which frequency is right for my application?

Different frequencies have different characteristics that make them more useful for different applications. For instance, low-frequency tags use less power and are better able to penetrate non-metallic substances. They are ideal for scanning objects with high-water content, such as fruit, but their read range is limited to less than a foot (0.33 meter). High-frequency tags work better on objects made of metal and can work around goods with high water content. They have a maximum read range of about three feet (1 meter). UHF frequencies typically offer better range and can transfer data faster than low- and high-frequencies. But they use more power and are less likely to pass through materials. And because they tend to be more "directed," they require a clear path between the tag and reader. UHF tags might be better for scanning boxes of goods as they pass through a dock door into a warehouse. It is best to work with a knowledgeable consultant, integrator or vendor that can help you choose the right frequency for your application.

Do all countries use the same frequencies?

Most countries have assigned the 125 kHz or 134 kHz area of the radio spectrum for low-frequency systems, and 13.56 MHz is used around the world for high-frequency systems. But UHF RFID systems have only been around since the mid-1990s, and countries have not agreed on a single area of the UHF spectrum for RFID. Europe uses 868 MHz for UHF, while the U.S. uses 915 MHz. Until recently, Japan did not allow any use of the UHF spectrum for RFID, but it is looking to open up the 960 MHz area for RFID. Many other devices use the UHF spectrum, so it will take years for all governments to agree on a single UHF band for RFID. Governments also regulate the power of the readers to limit interference with other devices. Some groups, such as the Global Commerce Initiative, are trying to encourage governments to agree on frequencies and output. Tag and reader makers are also trying to develop systems that can work at more than one frequency, in order to get around the problem.

I've heard RFID can be used with sensors. Is that true?

Yes. Some companies are combining RFID tags with sensors that detect and record temperature, movement and even radiation. One day, the same tags used to track items moving through the supply chain may also alert staff if they are not stored at the right temperature, if meat has gone bad or if someone has injected a biological agent into food.