The application is simple—we want to prevent bicycle theft. Where would such tags be placed? Could they be embedded into a bike frame, for example? And which frequency should be used?
Radio frequency identification has been used to prevent bicycle theft. The U.K. government's Home Office helped to finance the development of an RFID-based bike-monitoring system, linked to the country's ubiquitous network of closed-circuit televisions (CCTVs) used for fighting crime. The system was tested at the University of Portsmouth, in collaboration with the Hampshire police department, and was launched in 2008 (see U.K. Government Supports Using RFID to Fight Bike Thefts).
The U.K. system features active 433 MHz RFID tags joined to custom-designed motion sensors. The housing of each tag is designed to attach to U-locks made by Kryptonite, or directly to bikes, scooters, motorbikes and other valuables.
There are, however, several challenges involved in designing such a system. The first is the relatively short read range of RFID technologies. Passive tags can be read at a distance of 30 feet or so, while active tags can be read from about 1,000 feet. Having readers located every 1,000 feet, on every street, would be impossible, of course, so it would not be feasible to design a solution that could locate a stolen bike.
You could, however, have interrogators covering areas in which people park. Another solution would be to use short-range ultrahigh-frequency (UHF) or high-frequency (HF) tags and readers in bike racks. An ID card with an RFID transponder could be employed to lock or unlock the bike. When the bicycle is removed with the ID card being read, the bike's tag would no longer be interrogated, and an alert could be issued to a security guard—or, as in the U.K. application, the event could be recorded by closed-circuit TVs.
Another challenge is how to affix the tag to the bicycle. If the tag is obvious, then it could be removed and left near the reader, and the bike could be stolen without detection. The tag would need to be either tamperproof (if it were removed, an alert would be triggered) or concealed. To embed the tag in a plastic component of the bicycle, you would need to work with a bike manufacturer. It would be no easy sell to get the manufacturer to add RFID transponders, however. And if you embedded active tags in the bike, you would need a way to change the battery after a few years.
As the U.K. system shows, it is possible to build a successful system. However, you would need to think through all design requirements.
—Mark Roberti, Founder and Editor, RFID Journal
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