FID uses radio waves to automatically identify or track personnel and materials. It has replaced the bar code in many applications where the bar-code-required line of sight is unavailable. A unique serial number is stored on a microchip that is attached to an antenna. This transponder, or ID tag, can either transmit to or be read from the RF reader.
The reader, which also contains an antenna, sends radio waves that the transponder then reads. There are three types of tags: active, passive and semi-passive. An active RFID tag includes a battery that powers the tag's internal circuits, allowing it to send signals to the reader. A passive RFID tag uses the electromagnetic field created by the reader to power its own circuits. The microchip then modulates the radio waves that the tag sends back to the reader, and the reader converts the data for use within the computer. A semi-passive tag uses a battery to run the tag's circuitry, but sends the information using only the reader's power.
Improvements in technology and changes in the national security outlook have made RFID solutions more attractive than ever to a number of markets. Applications in access control and integrated personnel tracking, transportation security, supply chain management and homeland security in particular have increased significantly over recent years.
Access Control and Personnel Tracking
Many access control companies offer RFID-based access. Some companies also now offer RFID access solutions that feature tracking options. Axcess International Inc. has developed a method to track personnel and assets that are critical to a company's security. The system, known as the Axcess ActiveTag System, "operates with personnel wearing Axcess active tags uniquely identifying each person, allowing the access control system to quickly authorize or deny access or detect the presence of unauthorized personnel in the area," said Allan Griebenow, CEO and president of Axcess.
Systems like this track personnel moving from one location to another and can deny access if they are not authorized to enter. Such systems can also identify and track who is in the building at all times, thus providing an accurate account of who did or did not get out of a building in an emergency. This is all accomplished with no buttons to push or cards to swipe. All cards can be read at any given time without having to send personnel through a choke point for reading.
RFID systems designed for use with large vehicles are a great asset to inventory and the transportation industry. Security personnel can equip rail cars with RFID tags to allow tracking by station and yards along the route. Cars can be rerouted at any time and shipments moved to another destination without any manual input. Some systems offer wireless sensing tags that can monitor temperature, humidity, pressure, radiation and even ammonia gases. With this type of technology, the temperature inside refrigerator cars can be tracked to ensure the integrity of their contents.
Companies like AWID and Nedap offer technology that tracks vehicle access to parking areas through tags on the vehicles themselves. Such systems may be enhanced by linking the vehicle to the driver, the truck to the trailer, and/or the trailer to its authorized cargo, in order to ensure that not only is the vehicle authorized to enter or exit the area, but the correct cargo is leaving with the correct truck cab, and the driver is authorized to take the vehicle out. This system is a viable method to prevent asset thefts.
The Georgia Institute of Technology's Parking and Transportation Department presently uses a vehicle location module on a portion of its campus transportation fleet. The department plans to expand the system to all buses and trolleys in the current fiscal year. The VLMs transmit the coordinates of each vehicle's location every 15 to 25 seconds. Their tracking system is integrated with a geographic information system, which identifies the location of the vehicle at any given time and estimates the arrival time of the vehicle at each passenger stop. Not only does the system determine time and route management, coupled with rider ship counts, it can determine the proper support to the campus of all vehicles in the inventory.
According to David Williamson, assistant director for transportation, the system "has two key features. First and foremost is customer service. The system provides the rider with much-needed information on arrival times of vehicles and takes some the uncertainty out of using transit. Second, one of our goals is dependable transportation service, and this means service that is on time. The system provides management the tools to effectively measure and improve on our schedule adherence."
Supply Chain Management
In June of 2003, Wal-Mart mandated that all of its top 100 vendors place RFID tags on all its pallets and cases by January 1, 2005. Wal-Mart hopes to use RFID to track the inventory of each case and the pallets containing the cases, while not having to open each one to determine the contents. More and more, supply chain practices allow commodities and products to be misdirected or lost, which is a nightmare for a large company trying to keep its inventories accurate and up to date. Thus, the move by Wal-Mart to shore up not only its internal procedures but also the methods of its suppliers is a step in the right direction.
Wal-Mart survives on being the low-cost alternative in the retail industry. According to Christy Gallagher, spokesperson for Wal-Mart, "Not only do we have the 100 initial suppliers working towards our goal, but 37 additional companies have volunteered to be a part of the process." Many of the companies, like Gillette, Hewlett-Packard, Kimberly-Clark, Sara Lee and Johnson & Johnson, are well on their way. Each company has its own method of dealing with the edict, and Wal-Mart understands that they may not all be able to tag 100 percent of their product. But Gallagher stated that the suppliers themselves are realizing the benefits of using RFID in this way. "Hewlett-Packard, for instance, is benefiting from the RFID tagging process by improving their own internal processes," said Gallagher, "thus making their own supply process more productive."
Randy Dunn, national sales and marketing director for ADT Security Systems, said his company is heavily involved in working with Wal-Mart's top suppliers. He indicates that "the companies involved are having to do three things: collect the data, manage the information and do something different with the data that they are not doing now." ADT is assisting companies with the collection of the data. "We also have certification labs that tell us where (an RFID) tag would perform the best, and this is where we can help the most," said Dunn. Very few suppliers have said they would not work to meet Wal-Mart's edict, but one supplier did say it preferred to put money into needed facility improvements rather than RFID infrastructure. Gallagher indicated that this is something each company would need to address, but Wal-Mart does not mandate that the supplier comply or else. "Customer service is always the way Wal-Mart handles its business, and we would gladly work a solution out with this vendor for a win-win."
The obvious question is, How much infrastructure should each of the vendors invest to obtain a viable return on investment within a reasonable amount of time? "One particular supplier wanted to invest $7 million in infrastructure, and we asked them why? Our intent is to make this beneficial to all and not a burden," said Gallagher. One vendor, Beaver Street Fisheries, will realize an ROI within a year. Gallagher hopes this trend will be the prominent one.
The Homeland Security Arena
Homeland security issues, including the use of detectors coupled with RFID, have become major initiatives within many institutions that develop sensors and sensor technology. Auburn University's Detection and Food Safety Center, which has been working in this area since 1995, is developing stamp-sized sensor tags called STags that will cost only five to 10 cents per tag. According to Dr. Brian Chin, the center's director, "They can be placed on appropriate fresh-food products, and with a target sensitivity of tens of cells, the sensors would transmit a host of information by non-line-of-sight radio frequency." For consumer safety, these sensors would measure temperature, bacteria counts, and other chemical and environmental changes.
For the food industry, these sensors can also provide traceability features such as origin, date and time of processing, shipment information and a range of other programmable features. The RFID STags would be found molded into the sides of plastic bottles, attached to the inside cap of glass bottles, molded into Styrofoam meat-trays and attached to plastic wraps.
Another university on the cutting edge of this technology is the Georgia Institute of Technology. The Food Processing Technology Division of the Georgia Tech Research Institute, headed by J. Craig Wyvill, is currently looking into the performance limitations of current RFID technology on food products, particularly where the product has a high water content or where individual items are tagged and then placed in a box that has another tag. Metal and water can both interfere with RF signals.
There is also a potential problem with reader confusion from partially read interior tags. When multiple tags are in the same proximity, "tag collision" can occur. The solution has been to program the readers to read at different times, even to the level of milliseconds. The advancement of RFID technology has opened up new avenues to help protect us on a private and a national scale.
Robert F. Lang is the director of homeland security at Georgia Tech University. Mr. Lang's more than 30 years in security have taken him from the FBI to the Lockheed Corporation, where he was the plant protection manager prior to joining Georgia Tech.