Radio Frequency Identification and the Electronic Product Code

Radio frequency identification (RFID) systems occupy an increasingly important role in asset-tracking and inventory management systems. Large silicon vendors now produce RFID systems, lowering costs while increasing supply. RFID systems could become inexpensive and offer enough performance to satisfy a wide range of commercial applications, one day connecting consumer products in a dynamic, real-time, automated supply chain. Research at the Auto-ID Center (http://www.autoidcenter.org)—with labs at MIT and Cambridge University—is attempting to overcome roadblocks in developing disposable RFID transponders. Along with a standardized network infrastructure, these transponders could tag and identify items as ubiquitously as the bar code does today. However, where bar codes require manual, close-range scanning, RFID permits remote, non-line-of-sight, automatic reading. RFID systems consist of tags and readers; tags store data and readers read tag data by wireless communication. In their most common form, tags consist of ICs attached to antennae. RFID systems are diverse and fall into several different categories. For example, they can be active (battery powered) or passive—systems that draw power from the reader. They can also be near or far field. Near field RFID systems run at, for example, 13.56 MHz, are limited to a few feet, and use an inductive power mechanism. Far field systems run at about 915 MHz, can achieve distances greater than 10 feet, and use an electromagnetic powering mechanism. RFID systems can also be read only or writable, and they vary from a few bits in size to thousands of bits. They can have limited capability or incorporate advanced functionality, such as encryption and access control. This wide variety of system types enables applications for many different types of industries and consumer uses.