RFID, Sensors and the Internet of Things

The use of a wide variety of terms to describe RFID technologies—and the lack of precision among those terms—confuses companies seeking solutions to their business problems.
By Mark Roberti
Oct 14, 2013

Pity the poor businessperson. He or she is interested in taking advantage of new technologies that enable a company to monitor the location or condition of assets in real time. But technology providers, users and the media throw about so many terms to describe these technologies—including radio frequency identification, sensors, mesh networks, Internet of Things devices and the industrial Internet—how does anyone begin researching possible solutions?

Articles in the mainstream press often conflate all these concepts. Writers sometimes refer to RFID transponders as "sensors" or "wireless sensors," either to avoid the use of radio frequency identification, which seems like jargon to editors, or perhaps because they aren't sure what the different terms actually mean.

Last November, for example, The New York Times published an article about General Electric's efforts to gather data from the many items it manufactures (see Looking to Industry for the Next Digital Disruption). "Today, GE is putting sensors on everything, be it a gas turbine or a hospital bed," the article said. It included no explanation of the different types of sensors. The "sensor" on the hospital bed is most likely an active RFID tag that broadcasts the identity of the object and its location. It's not clear what GE monitors within its gas turbines or which technology it uses, but the company's Web site refers to the use of passive RFID tags for asset management.

The term "Internet of Things" was coined in 1999 by Kevin Ashton, then executive director of the MIT Auto-ID Center. It helped explain the concept of putting a low-cost RFID transponder on, say, a case of shampoo to enable tracking of the product from manufacture through sale. But some now use the term interchangeably with sensor networks and mesh networks. To confuse matters more, the term has broadened over time to include sensors inside medical equipment or photocopiers that can report on a machine's condition through an Ethernet connection to the Internet, and almost any other technology that connects a machine to the Internet.

Whether RFID tags are sensors is open to debate. The Oxford English Dictionary defines a sensor as "a device which detects or measures a physical property and records, indicates, or otherwise responds to it."

A basic RFID tag detects the presence of an object and can tell you its identity. It could be argued that this makes an RFID tag a sensor. Ashton addresses the issue in his column, "Making More Sense." "RFID tags enable computers to sense identity, and knowing what something is almost always is a prerequisite to being able to use other sensory information, such as temperature," he says. "I consider an RFID tag a 'sensor' because it can detect something about the physical world remotely and by proxy."

But passive RFID can also be used simply as a tool for counting objects, such as clothing items on store shelves. When used like a bar code, RFID does not seem like a sensor.

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