As attendees of this week’s RFID Journal LIVE! conference entered a room to hear the event’s opening keynote address, they were greeted by two large video screens that welcomed each of them by name. The electronic greeting was made possible thanks to portal readers that read a HF RFID tag attached to their name badge and carried an ID number and their name. The badge system, used at the conference to track the volume of attendees for each session, was developed and deployed by Princeton, N.J.-based RFID systems provider Avante. But at Avante’s booth in the LIVE exhibit hall, the company demonstrated a totally different RFID system—one that can be used to secure and track cargo on ships, as well as track cases and pallets of goods in the retail supply chain.
The system is built around Avante’s Zoner tag, an active UHF tag that emits a series of RF signals at several distinct and programmable power levels so that a reader can ascertain the distance between it and the tag from between 10 and 100 meters. The tag will first emit a signal that can be read by a reader 100 meters away, then one that can be read at 80 meters (or at whichever length for which it is programmed), and so on. The Zoner tag can be set to emit its beacon signal on demand or at programmable time intervals. When used with three or more readers, the readers can triangulate to find the tags to within 10 to 20 feet.
Avante believes that Zoner tags could be used to monitor the integrity of cargo containers on a ship. Such a system involves installing RFID readers in a cargo hold and placing one or more Zoner tags, which have a magnetic backing that enables them to be attached to the inside of each secure steel container. Once the containers are in place in the ship’s cargo hold, readers installed in the hold would take a baseline reading of the signals being received from each tag, which is associated with the container in which it is stored.
If the reader picks up a signals from one of the two or more of the lesser-reaching power levels at which a given tag is transmitting, the reader would infer that the container has been opened. (It could also mean that the container had been moved closer to a reader, so system-monitoring personnel would need to know of any scheduled movements of the containers.) Kevin Chung, president of Avante, says that using more than one tag in each container would serve as a backup in case one of the tags was not working and also as a way to double-check that the container has in fact been compromised and a change in signal strength is not due to a dysfunctional tag.
The tags communicate with fixed-position readers, or they can be read by Relayers, Zoner tags with a specialized processor that enables the tags to function as a reader as well as a tag. By using the Relayer tags, which form an ad hoc network when attached to assets in the field, users can achieve more coverage of an area through a lower number of fixed readers. A combination of fixed readers and Relayer devices can be used for maximum coverage. For a cargo security application, the Relayer devices would be attached, via magnet, to the exterior of containers and would send tag data wirelessly to a hub that is linked directly into the system administrator’s computer. The fixed readers feed information directly into a computer through a USB port.
Chung says his company’s approach to securing cargo is unique and foolproof. Rather than equipping a container’s seal with a tag that would send a signal to administrators if the seal were broken, the Avante system would immediately signal any type of opening in the container. “It doesn’t make sense to put the tag on the seal, because anyone with a cheap blowtorch could cut a hole into a shipping container without touching the seal,” says Chung. If someone used a blowtorch to cut a hole in a container equipped with a Zoner tag, the hole would enable more of a tag’s lower-power signals to reach a reader, thereby causing the Avante system to send out an alert.
Avante also developed software, based in Microsoft’s .NET framework, with a graphical user interface that shows a representation of the tags being monitored. If any reader receives two or more new signal levels from a Zoner tag, the software sends an alert, either to the ship staff or to the appropriate port authority, via a satellite communication system, that the container in which the tag resides has likely been compromised. “We recommend that any exception should go directly to the destination custom and port authorities. It will be the management of those authorities to inform or not to inform the staff on board of the ship, depending on the level of trust,” says Chung.
The Avante software would run on a computer that links into a GPS location reporting system and a satellite or other suitable communication system. It could also be linked to optional digital video recording device fed to customs authorities or independent monitoring agencies. Avante firmware controls the tag in terms of transmitting frequency, channels and the data formats that are embedded into the Zoner tag and Relayer reader.
Chung believes that the Avante Zoner tags would also work well for tracking cases and pallets in the retail and Department of Defense supply chains because they would eliminate the problems associated with passive UHF tags’ shorter read ranges and vulnerability to breakage and signal interference. Companies could use the Zoner tags just as they currently use passive UHF tags, except that the Zoner tags could be placed inside cases and attached to pallets through a number of methods, including Velcro and straps. Third-party logistics carriers deployed by suppliers could collect and return the tags to the suppliers. Avante readers, either fixed or Relayer devices or both, would need to be installed in the facilities belonging to the supplier, retailer and any participating supply chain partners’ facilities. Avante provides a software applet that users of the Zoner tags would need to install in order to pull the electronic product codes and any additional data from the tags (since the Zoner tags can hold 4 kilobytes of data, they can store information from sensors, such as temperature readings) and feed it into the user’s software.
For cargo and asset tracking, the Zoner tags are available with a 433 MHz operating frequency—the one used by cargo security systems from other vendors such as Savi Technology—because 433 MHz offers a good read range. For EPCglobal applications in the retail supply chain and Department of Defense, the Zoner tags are available with an operating frequency of 860 to 960 MHz.
Chung says the Zoner systems are also attractive because they cost less than other RFID systems. Chung says a typical cargo security deployment of the Zoner system on a container ship carrying up to 3,000 containers would cost $10,000 for coverage of a ship’s cargo hold. The tags and readers would account for $6,000 of that cost, and the balance for computer and satellite communication gear would comprise the balance. He says that coverage of a typical port terminal yard would cost $1 million.
Avante is hoping to partner with companies to license and deploy the Zoner systems. Chung says a company that works with shipping agents, such as Maersk, could distribute and ensure proper usage of the Zoner system in the field.