What Is the Difference Between RuBee and RFID?

Which technology is better?

—Name withheld

———

RuBee (IEEE standard 1902.1) is a form of radio frequency identification (though its creator does not agree with me on this point.). It uses low-frequency (HF) 131 kHz radio waves and active transceivers that communicate peer-to-peer. Different RFID systems use different communications methods. Ultrahigh-frequency (UHF) systems employ backscatter, in which energy is received by a tag and reflected back. As a result of this, UHF can cause problems in an environment containing a lot of metal, which reflects energy and can cause the signal to bounce around.

RuBee systems create a large read field, and changes within that field enable tags to communicate. Imagine filling a room with liquid and then having a device that could create a series of small waves. They would ripple through the liquid and be detectible by a reader designed to measure those waves. This is a simplistic explanation, but what I'm trying to show is that RuBee is not a line-of-sight technology. Imagine you had a tagged object 20 feet from a reader and you had a large metal plate between the reader and that object. With a UHF system, there would be no way to read the tag. With RuBee, the "waves" would flow around the metal plate and be picked up by the reader.

Is RuBee better than passive UHF technology or other kinds of active systems? The answer depends on two things. One is your definition of "better" and the other is your particular application. Let's take the second one first, because that's more straight-forward. In terms of performance, RuBee is ideal for applications that involve tracking metal object or those in an environment containing a lot of metal. It has largely been used for weapons tracking for this reason, at it performs better than other types of RFID for such an application. In other words, you can read tags on guns in a gun rack more consistently with a RuBee system than with any other kind of system.

The definition of "better" is a little trickier. If better is simply performance, then, as stated above, there are applications for which RuBee is superior to other types of RFID (just as there are applications for which it clearly is not as suitable). But in business, performance alone is the only metric. (Often, companies also want to consider cost, and you might want to consider convenience as well.) So while one company might say that it would spend more to buy a RuBee system that tracks guns accurately in their racks, another might opt not to spend as much, and would compromise by, for example, using a passive RFID system that costs less and then asking people to check their guns in by presenting them to a reader.

RuBee is not well known, which is too bad because there are clearly applications for which it works well. Lockheed Martin recently licensed the technology, so perhaps that will change (see Lockheed Martin Offers RuBee Solution for Monitoring Munitions).

—Mark Roberti, Founder and Editor, RFID Journal