No, I am not going to preach to you about deforestation and global warming, although I fully support "going green," and RFID can help reward consumers for recyling, but that is not what I am talking about when I say Environment.

Rather, this is part 2 in a series started a few weeks ago about choosing the right frequency for a given RFID application. Today we will discuss how environmental factors might influence your decision to go with either frequency band.

So, what I am talking about, environmental factors? Everyone knows that metal is bad news for RFID right? Well, sure, metal surfaces can reflect electronmagnetic fields, wreaking havoc on your system, and magnetic fields can induce eddy currents in metals that will in turn create other magnetic fields that can effectively cancel the signal, and blah blah blah, metal will cause headaches, good luck. There are ways around these issues, perhaps by using foam spaces between tags and the metal surface, or by using ferrite core sheets as isolators between an antenna and metal, and a lot of RFID applications become plausible using these kinds of solutions, as long as you aren't trying to read a tag through metal. But metal things aren't necessarily evil, and even could be essential when considering shielding. Every device containing a radio needs to be certified by some sort of regulatory body (like the FCC) before it can be sold, and some certifications don't allow you to be radiating electromagnetic waves all about, so a nice metal shield may come in handy (assuming you don't create any slot antennas.) There is no clear winner here in the "frequency war," both bands are affected and there is a lot to consider.

 Water and other liquids can also cause some issues. Liquids, and even plastics, have a higher relative permittivity than air, meaning the electric fields produced by radios tend to be absorbed by the medium, and the effects are greater with higher frequencies. This is why in submarine movies, they always have to break out the ultra-low-frequency radio to communicate when they are deep underwater. Luckily HF readers use magnetic induction, and they don't feel these kinds of effects nearly as much as their UHF bretheren. So when reading tags on liquid filled bags, HF might be your best bet, but don't forget about inductive UHF tags, because if range is not an issue, that could be an option as well.

But enough of the physics lesson, and environment isn't all materials. What about the place you might be using RFID? Is it a busy store, a crowded airport, or maybe a deserted (other than robots) packing facility. In a warehouse, you are probably more interested in picking up every item that moves through the dock door, and maybe in a store you want to know all of the people that step through the door, and provide each of them tailored service. But then again, you probably don't want to accidentily pay for the person's purchase in front of you at the counter because you have an RFID enabled credit card. Privacy is always a concern with RFID, and a lot of times it concerns where people are in relation to one another. If you want general information about people and things, and there are tons of them moving through gateways, longer range UHF applications work great. But if you want to be sure exactly who or what you are talking to, HF's proximity is your friend. Although, apparently the government isn't all that concerned with knowing what face goes with which passport as you move through customs.

I hope this gives you some idea of the factors that may impact your application. It can be a complicated business to fit RFID into every environment, but now you know some of the questions to ask when taking the RFID plunge.

In the final part of this series, we will talk about how your decision for HF vs UHF is influenced by the most powerful force on earth: money.

With all of our customers, this is usually the first question that we need to address, “Should I use HF or UHF?” The easy answer is, of course, UHF allows for longer range, HF requires proximity. I read an article the other day about a vendor that believed this and tag price was all they really needed to know, and they are now starting to think they made the wrong choice.

In later posts we will go into more detail, but for now here is a quick overview of differences in tags and in readers. HF tags typically have a large user memory bank, memory on the tag that a user can use however they please. Certain HF tags also use secure communications protocols, protecting data as it moves between the reader and tag, and can provide anti-counterfeiting measures for high value products. But security and memory come at a price, literally, with some tags costing more than $1 per tag.

On the other end, UHF tags are almost the complete opposite. Smaller memory, usually only enough for an Electronic Product Code (EPC), no secure protocols, and long read range, all for much cheaper than HF tags. However, UHF tags with large user memory are starting to gain traction, and some tag manufacturers have started making inductive UHF tags, which have a more restricted range, but are extremely inexpensive. As a result, I wouldn’t be surprised to start seeing UHF gaining popularity in more markets.

But the story doesn’t end there. HF readers are much cheaper than UHF readers, NFC phones are becoming more popular, and contactless payment is becoming more pervasive (been to Best Buy lately?) all support for HF. So what does all this mean? In my opinion, it comes down to this: if you have many items to tag and few read points (like in a warehouse), UHF is a more logical choice, but if you have many read points in many places (such as cell phones) or you are tagging high value items, HF will be more beneficial. There are always exceptions, but this is a good start to making sure you don't end up with millions of the wrong type of tags.

Here is some commentary from Sean Loving, SkyeTek's founder: 

While the buzz is squarely on Supply Chain Management (SCM), I happen to believe that SCM is the least interesting part of the RFID market. Frankly, SCM is downright dull when you start to understand enabled reader technology.

At SkyeTek, we divide the embedded reader market into two primary segments: dedicated and enabled.

Dedicated readers look and smell like RFID readers - things like dock-door readers, handheld scanners, label printers, etc.

Enabled readers are far more interesting, because most of the time you wouldn’t know or expect RFID to be in there - things like medical devices, exercise equipment, and consumer electronics to name just a few of the places we have embedded enabled readers.

Though it gets somewhat scant industry attention, I expect the mega opportunity in RFID will have almost nothing to do with SCM. While analysts have not covered embedded RFID readers (especially the enabled portion) and thus there are no reports to support this theory, (though I’d welcome the research…are you listening VDC, IDC, Gartner, etc.?), I have strong anecdotal evidence that comes from our customer base.

Many if not most of our customers are not your typical SCM RFID install. Rather they work in vertical industries where RFID was not even in the consideration set a year ago, and amongst their competitors probably still isn’t. Yet our customers are solving real problems and enjoying real benefits from enabled solutions.

From our perspective, the attention that WalMart and the chips inserted in “Muffy” have generated is certainly a positive. It has gotten people thinking about what RFID can do for them, and I think it is worth pointing to some illuminating facts from our business:

(a) SkyeTek had already enabled over 100 unique applications with RFID before ever making a single outbound sales call

(b) we continue to see increasing demand in the form of inbound inquiries for embedded reader technology in some form or another.

The point is that once people start thinking about RFID, they end up applying the technology in totally new and innovative ways. Usually the more deeply they embed RFID into the product or service they already provide, the more interesting and useful the application becomes. Again, from our own sales leads we can say that when embedded customers seek out RFID solutions they occasionally find the marketplace offers what they need. More often, at least outside of SCM, they quickly learn how hard it is to fit a dock door reader or an animal scanner into their next generation DVD player, stair-climber, or microwave oven.

While the business motivations of customers are predictable (protection of consumables revenue, security and authentication, inventory and positive id), the functional and performance requirements are diverse, from readers in cell phones to readers in conveyor belts. Regardless of the type of equipment, OEMs are finding they need embedded reader technology to meet the most important requirements of their particular application and market, and this means looking beyond the purpose-built, vertical-specific hardware devices that seem to dominate the market.

In order to extend RFID to 1000s of new applications, a new technology and approach is needed to address this vastly underserved opportunity, and this means embedded readers. At SkyeTek we are looking beyond the current landscape and, along with others, are working to make embedded RFID reader technology more readily available, and able to meet the widespread but under-reported demand that is brewing across every vertical and horizontal market, and not simply working within the SCM doldrums.

We at SkyeTek are lucky to be exposed to ideas in their infancy. Lots of ideas. Working for SkyeTek, where we are focused on the embedded reader market, the ideas about how RFID will change the world go way beyond tracking goods. We sit with customers every week who tell me about their visions. Some simply want to improve existing products by adding RFID as a feature to do the same thing they’ve always done – but better. Others are integrating RFID with sensors, controls, wireless networks, and other technologies to create new and unique products. If even a small percentage of these ideas succeed, we stand to see a revolution in retail marketing, life-changing advances in medical treatment, a change in what we carry in our pockets, and countless other improvements in the way we move through our day. We might even have more fun on our vacations. (We're still engineers at heart, so we love automation and streamlined processes).

There has been much press in the last few months about security and privacy concerns related to RFID technology. Even The Today Show had a segment questioning whether the new smart cards were really that smart. First of all, I think it’s GREAT that RFID-enabled technologies are entering the American vocabulary on morning shows next to what to wear for fall and how to cook the best Thanksgiving turkey. Surely, this is a positive indication that RFID is starting to take hold and becoming more relevant to our everyday life. But to address the controversial issues surrounding RFID, these are nothing more than challenges that will take time and creativity to overcome. And overcoming these challenges is what makes working with emerging technologies fun!

RFID is still a relative newborn in terms of mass adoption. Of course, the internet wasn’t born overnight, barcodes took 30 years to become pervasive, and the evolution of cell phones and other mobile computing and communication devices is still evolving. All of these technologies changed the way people live, and we are excited to think of all the ways that RFID is likely to do the same.

These entries will focus not just on the neat ideas that will revolutionize the way we live our lives, but also discuss the associated challenges whether they be technical, political, social, or economical. By discussing these issues, I hope to open a dialogue for creative solutions that we at SkyeTek are now and continue to be aggressively involved in solving.