ADT Europe, a part of Tyco Fire & Security, has installed the first permanent facility in Europe for testing dense RFID reader environments, or areas in which multiple interrogators deployed close together can potentially interfere with each other.
ADT’s dense-reader testing facility, focused on UHF interrogators, is installed in Echt, Netherlands, at the site of the ADT Europe RFID Performance Lab, the EPCglobal-accredited testing center for tags and readers.
The dense-reader testing facility is inside a warehouse and can accommodate tests of five to 15 RFID portals and associated hardware. ADT has replicated adjacent dock doors by installing RFID antenna portals across 10 storage bays. Each bay is 3.7 meters wide, allowing goods to be passed through to accurately simulate a normal dock door.
“It’s the worst-case scenario because the spacing between the portals and antennas is minimal. They’re back to back,” says David Berglund, who is responsible for RFID solutions in Europe for Tyco Fire & Security.
ADT has constructed the facility so that readers can be quickly exchanged during testing, allowing customers to try out a variety of deployment scenarios for readability under full compliance with ETSI regulations, which limit the number of radio channels available for UHF RFID in Europe. In the United States, UHF interrogators can transmit over 50 channels in the 902 to 928 MHz range. In Europe, UHF interrogators are restricted to just 10 channels from 865.6 to 867.6 MHz.
“What we’ve seen is that over the last 12 months, dense-reader environment solutions have been evolving,” he said, adding, “As the reader technology and the ETSI UHF RFID regulations evolve, end solutions change. In order to make sure solutions meet customer requirements, we need to have an installation like this to stage and test before going to the customer.” Solutions are designed for retailers or other end users like logistics operators.
So far, ADT has used this facility to run tests involving a maximum of 10 portal interrogators reading tags and five other interrogators transmitting and acting as interferers. All readers and tags complied with EPC Class 1 Gen 2 standards. These tests were performed for a major European retailer.
The retailer, who Berglund declines to name, took the results of the dense-reader test and set up a predeployment test at its own facilities. It achieved a read accuracy rate of more than 99 percent on tagged roll cages at 16 doors.
Each test conducted at the dense-reader lab is custom designed by ADT based on the project requirements.
“We use this facility to replicate the environment [at the client’s site] and stage a test,” Berglund says. If a customer uses metal roll cages, ADT will bring the roll cages to the lab for testing, he explains, adding, “This permanent dense-reader test facility allows us to set up and run tests in a flexible way.”
ADT has also developed its own network-based RFID reader-synchronization solution. The software can be loaded onto any reader, making it possible for readers to work alongside each other without interference and in compliance with ETSI regulations. The regulations still require a reader to “listen” to find out if a channel is in use before it sends a signal, even though this rule is no longer required by the European Union (see EC Ruling Harmonizes Use of UHF for RFID). John Falck, the head of the ETSI group working on RFID, says ETSI may remove its requirement for “listen before talk” by 2008.
ADT’s solution synchronizes readers centrally on the network, while readers keep themselves in sync through software on the reader. It is being used by customers in Europe and was developed so it can adapt to evolving regulations.