Gen 2 Tags Track Runner, Motorcycle Speeds

By Claire Swedberg

May 1, 2008—SAI Timing and Tracking is offering a racer's bib with a disposable Gen 2 passive RFID tag to track a runner's time during a race. Developed by ChronoTrack, a sports timing and tracking company based in Evansville, In., the system replaces a more expensive and labor-intensive transponder system requiring racers to use battery-powered transponders, then return them after a race to be reused at other races.

Meanwhile, Hardcard Systems and Alien Technology are testing a Gen 2 RFID tag to track racing times for motorcycles.

Designed and developed by ChronoTrack, the new SAI Timing system has been employed at marathons in Las Vegas and Los Angeles with a 99.84 percent read rate, according to SAI Timing's cofounder, David Simms.

Marathon participants typically employ an active transponder that they attach to their ankle, shoe or shoelace to track their times as they complete sections of a race and then cross the finish line. The problem is the cost of the transponders—usually about $35—and the need for runners to return them when the race ends, causing a congestion of participants waiting in line to do so. The former system was also labor-intensive since each printed bib had to be matched to a transponder by marathon employees who input the runner's ID number for each transponder to link them in a database.

SAI's solution produces racer bibs with ChronoTrack D-Tags—adhesive labels with embedded passive EPC Gen 2 RFID tags. To encode and print the D-Tag and bib, SAI uses a Lexmark T640rn monochrome RFID laser printer-encoder (see New Office Laser Printer Encodes Tags), says Rick Kallup, Lexmark's senior industry consultant and RFID business development manager. When runners register for a race, they are assigned an ID number and a corresponding bib printed and encoded with that number. When they pick up their bib on the day of that event, they pull the RFID label from the bib and attach it to their shoe.

The system employs Impinj Speedway RFID readers and antennas installed under checkpoints along the racecourse and at the finish line. In that way, they can capture the tag's unique ID number as the racer passes. Impinj middleware running on the interrogator translates the data, and the reader transmits it to SAI's back-end server via an 802.11 Wi-Fi or GSM connection. SAI then makes that data available by posting the scores online, as well as text-messaging each racer—for them to read either during race (assuming they are carrying a cell phone) or afterward—or to their friends and family as they pass each milestone.

The system was developed in the fall of 2007, and was first used in the Las Vegas marathon in November of that year. Since then, it has been utilized in at least three other races. The system's accuracy has been tested by track-and-field timing company Lynx System Developers, Simms says, and has proven to be just as accurate as the former active transponder system.

EPC Gen 2 passive UHF tags typically have a read range of 30 feet, but SAI Timing's system can pinpoint the exact time a runner reaches a checkpoint or the finish line. Simms declines to specify how the Impinj RFID readers accomplish this, calling it a proprietary technology, but notes that the company has found the tags work best on runners' shoes. Still, Impinj continues to work on other options as well, such as putting tags on the runners' chest. "Our best results have been on the shoes," he states. Simms says he expects between 500,000 and 750,000 runners will have used the system by the end of 2008, with that number jumping to several million in 2009.