Radio frequency identification
Radio frequency identification (RFID) is a wireless method for automatic identification. It employs wireless RFID tags (transponders) that can store small amounts of information and transmit them to an RFID reader. RFID technology can be used to identify anything, and are commonly found as part of a supply chain management (SCM) implementation. RFID tags can be active (powered) or passive (unpowered).
Radio Frequency ID: History
Radio frequency identification (RFID) was a product of World War II and was first used by the British to identify returning British warplanes. While the radar would show a plane, it could not distinguish whether the plane was British or German. The RFID system in this application came to be known as identification friend or foe. Air traffic controllers use the same kind of system to identify the aircraft on their radar screens.
Harry Stockman in 1948 is credited with the first research on RFIDs in his paper entitled “Communication by Means of Reflected Power.” However, the move from theory to reality took some thirty years and we are still improving on the early designs as new application requirements evolve. The controversy around RFIDs comes from the ACLU, the Congress, Homeland Security, and the general populace. The following quote from Senator Debra Bowen is not only cute but also potentially correct. It points out that these small devices could be used to track people, which is in some context clearly a violation of one’s privacy. “How would you like it if, for instance, one day you realized your underwear was reporting on your whereabouts?” California State Senator Debra Bowen at a 2003 hearing
With privacy at the center of the RFID debate, the Department of Homeland Security is attempting to rename its RFID technology “contactless chips” to deflect any of the public’s RFID concerns. Regardless of the name, RFIDs will be imbedded in the back covers of U.S. passports beginning in 2006. The RFID will automatically transmit the information printed on the inside of the front cover of the passport. On the surface, this could speed up the lines at immigration, but an RFID in the wrong hands could lead to identity theft.
Radio Frequency ID: Technology
RFID technology is very simple—it is a radio on a chip that can send and receive information. That said, the most interesting part of the RFID chipset is the powering mechanism for the RFID tag. Passive tags are the smallest and cheapest since they have no internal power supply. They use the small amount of electrical energy induced in the antenna during the receive process to power the transmitter. Because there is very little power, the response from the RFID tag is typically just an ID number. These tags are typically thinner than a sheet of paper and measure some 0.4 mm by 0.4 mm. (There are 25.4 mm in an inch.) Because of the low power, the range is from 10 mm to 5 meters (about 15 feet).
Active tags, on the other hand, are somewhat larger and significantly more expensive because they have an internal power supply. The range of the RFID tag is on the order of tens of meters; RFID tags also have larger memories that can store more than just an ID number. The battery life of these devices is measured in years, and they are about the size of a nickel.
There are four ranges of tag frequencies available in the U.S. and in some cases worldwide. These fall into the low frequency (LF) category at 124 kHz (U.S.) and 134.5 kHz (worldwide). The high frequency (UHF) category is at 13.56 MHz (worldwide). Ultra high frequency (UHF) tags are in the 868–956 MHz range worldwide, while the worldwide microwave category is at 2.45 GHz. The most popular tag frequencies today are in the UHF range.
Radio Frequency ID: Today
Generation two (Gen 2) of the RFID technology will be out later this year. It improves the air interface and introduces some even smaller power supply options. Most importantly, it defines the semi-passive RFID tag. This tag uses a low power battery and the tag is programmed to turn on at present intervals. For example, the tag could be set to wake up every thirty minutes and transmit it identifying information. This allows for a significant increase in battery life and will work well in environments that are technically stationary (i.e., environments that have slow speeds and limited range of motion). For example, a pallet of televisions is technically stationary as it slowly moves from the factory to the truck to the storeroom to the showroom to the check-out station.
Today’s chipset prices range from about $5.00 for an active tag to about $0.25 for a passive tag. At $0.25 per tag, it will be a long time before a tube of toothpaste has an RFID for inventory control. However, at the target price of $0.03 almost everything could be tagged with a RFID chipset. Today we find RFIDs in library books, on animal collars, attached to beer kegs and pallets, and imbedded in ID badges. Both California’s FasTrack and Illinois’ I-Pass use RFID tags on cars to speed toll booth processing. Some cars even have RFIDs in the car keys so that the doors automatically open as the keys approach and lock when the keys are out of range. The use of RFIDs in soccer balls and bicycles is being trialed as a means of determining if the ball crosses the goal line or bicycle crosses the finish line. The Bosch power tool company notes that the use of RFIDs in power tools on the job site could reduce the $1 B in lost tools each year. To prevent counterfeit chips, some casinos are trying to use RFIDs to brand their chips.
Finally, there is much discussion about the use of implantable tags to keep track of children and prisoners. Once again, RFID tags will move into the realm of an invasion of privacy. However, today it is possible to locate people via the GPS chips in the contemporary digital cellular phone when it is attached to a base station.
Why RFID? or Why Not?
The jury is still out on the ultimate business value of RFIDs but there is an increasing amount of literature about the decisions thus far. For example, Gillette has found that it can use RFIDs to track products from the warehouse to the store shelves. They have found it to be particularly useful to map the timing of an advertising promotion with the arrival of the product on the shelves. It appears that the most successful promotions are those in which the product hits the shelves just before the promotion is rolled out.
Pfizer is holding off on RFIDs because of the current high cost and lack of standards. They believe that to be successful with RFIDs, they must have a data architecture that supports RFIDs and RFID tags that have a high degree of readability. In their words, “RFID is not a slam dunk!”
Target has a number of stores up and running using RFID technology from ADT Security Systems and wireless LANs from Symbol Technologies. One hundred of their consumer goods suppliers use RFIDs, and Target is adding RFID capability in 40 stores per week.
Other opinions include Bear Stearns being bullish on RFIDs while noting that ROI will be a near-term challenge. Microsoft wants RFID capability as an integral part of it Windows architecture and H-P tags all laptops sent to Wal-Mart stores. It appears that the question is to stand pat or risk RFID. Regardless of the many opinions today, RFID tags will become a part of our lives in the near future. George Orwell may have been right; he just got the year wrong.
McCarran International Airport
McCarran International Airport in Las Vegas, Nevada seems to be on the top of everybody’s list when it comes to RFID tags and wireless LANs. Over the past year, the airport has spent $120 million to create an automated baggage system. Basically the system uses an RFID tag on the baggage tag and a system of conveyor belts and RFID transceivers that query and route the bags to the appropriate plane. To test the system, the airport bought all the used bags in Las Vegas from secondhand providers such as the Salvation Army. They used 3000 pieces in the tests with very impressive results.
The system is quite simple but the cost justification and test results are pretty impressive. Basically, the passive RFID tag transmits a 10-digit ID code to the airport’s Oracle baggage database. That database is linked to the airline databases that contain the passenger name records (PNR). By using the PNRs, the system knows this bag’s destination and sends it to the right aircraft. On an average day, McCarran processes approximately 65,000 outbound bags using traditional barcode laser scanners that have an accuracy of 80–90 percent. Even at 90 percent efficiency there will be 6500 misrouted bags per day. On average, a late arriving bag costs the airline about $90 in processing and delivery, not to mention having to deal with the perturbed customer. Annually, about $1 billion is spent on lost baggage worldwide. An RFID system that is 99.8 percent accurate could reduce that number to around $20 million per year. McCarran achieved a 99.89 percent accuracy rate and in one test run it had only one misrouted bag out of 3000—pretty impressive.
McCarran also spent $75,000 to implement an Aruba wireless LAN that provides Wi-Fi access at no charge to the user. Currently they have 30 nodes in the airport with 30 more planned for this year. This should result in 100 percent coverage of the terminal and tarmac areas. The wireless LAN is connected to a 3 Mbps DSL connection. So far, the system has averaged 300 user loads with a 1200 user load during the 2005 Consumer Electronics Show without any significant performance problems. In fact, the company that provides wheelchair assistance now uses the wireless LAN with PDAs to get wheelchairs to the correct gates. This system has been superior to the traditional two-way radio system.
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