Oct. 28, 2009 – Two weeks ago Mojix announced field trials of its self-described "breakthrough" passive RFID technology. Senior V.P. of Sales and Marketing, Kevin Duffy, explains why he thinks you need to take a look at this.

The Mojix product introduction in April, that here was a passive RFID reader technology that had a huge range, grabbed a lot of attention.

DUFFY: Range is a point to point kind of thought. But, if you take range and spin it sort of left to right, you end up with coverage. So long range equates to large coverage, and large coverage equates to wall to wall visibility for assets and goods that are tagged as opposed to a portable based approach. That is really is the nexus of what we are approaching.

Is this primarily UHF or HF? What kind of frequencies do you cover?

DUFFY: Well, it is EPC Global compliant, so that means that it is whatever is dictated by that standard, whether in the United States or in Europe; whatever band is utilized by that sovereign. For general purposes it is considered UHF.

The way you described it, it starts to sound along the lines of a real time location system, not just asset tracking.

DUFFY: That is actually a very good way of describing it. Active technology utilizes expensive tags, sometimes to tens of dollars. And those would have been thought, until now. as the only way you could do real time locations.

Because of the sensitivity of the Mojix receiver, we can receive the signal from a passive tag, which is a few pennies. We can receive that signal from hundreds of feet away. The Mojix system is rated at 600 feet, but we have actually been able to do much greater than that.

When you are detecting tags, when you are talking about real time location or imply that, is it done by zones or by some other methodology?

DUFFY: The Mojix system effectively sets up the interrogation zones. If we separate the action of activating a tag, which is providing energy from what was considered a reader before, in the transmitter section, the Mojix system has the same. Instead of one single transmitter and one receiver pair, we have one receiver that receives all the energy across hundreds of thousands square feet.

The function of activating tags is done by what we call distributed exciters. These exciters are placed all about the operation, whether that is a factory or warehouse, a backroom or a retail environment. What we call excitation nodes, or eNodes, provide activation energy throughout the operating space. Then the Mojix STAR receiver would receive that energy. So you can break it up into zones, as you call it, or you can even get resolution on your tracking in an area that is even tighter than what is provided by a single eNode.

Now when you say exciter, would that be called an antenna on a different reader?

DUFFY: Yes. Our eNodes are pretty much equivalent to a traditional reader, because they can have multiple antennas themselves.

A traditional reader has one source of energy and one place of receiving. It fans that energy out by having external antennas; a couple for transmitting and a couple for receiving. Mojix excitation nodes can also have external antennas, that spreads that energy even further. So, eNodes are there to provide localized delivery of activation energy for tags and, can be utilizing external antennas to save energy.

The way you think of that is using a flashlight versus a light bulb. You can have a broad antenna which provides sort of a light bulb-like effect; but you can have an antenna which is very focused like you would do with a flashlight.

Did I get it correctly that the eNode has antennas, so would you have multiple eNodes and each with one or more antennas themselves?

DUFFY: That is correct. And those eNodes can be different for each zone, as you say. For example if you look at a warehouse, you would place
eNodes around dock doors and those antennas would be shaped so that the energy from any individual door is only directed at that door. Whereas in working inward from those doors, you would have eNodes placed in and among shelving. That would be a different shape of antenna, provide different kind of radial coverage for the items on those shelves. Likewise, you could have coverage in work-in-progress areas, or assembly or staging areas, and those would be eNodes placed to cover those areas with yet a different radiation pattern.

So, one STAR would process all of those different use stations, dock doors, perpetual inventory and shelves, WIP or staging. All that would change is the shape of the antenna to be tailored to the individual use case.

So the eNodes report back to a reader, is that correct?

DUFFY: That is right. What we call the Space Time Array of Receivers.

Okay, that is the STAR. And then the STAR/reader would gather the data from these nodes; the nodes are gathering data from the use of an antenna; and how many nodes would report back to one receiver?

DUFFY: Just one caveat: it is hard to call the STAR the reader because it is really the zone controller. The eNode controllers which controls all of the eNodes. And you can have up to 512 eNodes per STAR for a Mojix receiver. That is the equivalent of 512 sub-systems.

Previously, each conventional reader system, like one of our competitor's, would provide an individual interrogation zone. One eNode creates an interrogation zone and you can have up to 512 of those on a single STAR. The STAR is the eNode controller.

Editor's note: See part 2 of this interview with Kevin Duffy tomorrow.