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Avoiding Active RFID Confusion
Issue #95 | Mar. 23, 2007 | by Erik Wood
It is interesting that while active RFID has been around much longer than UHF Passive, we already have reached true standards-based interoperability in UHF. But strangely enough, not with Active. And true interoperability, based on reliable standards, is what the goal of any technology should be.
Even where there is a real standard established in the active RFID space, the ISO 18000-7 standard, on the 433.92MHz frequency, we learn nothing is that simple. With the large global military and port installed base at 433.92 MHz, and relevant manufacturers of active RFID container tags aboard, can’t we all finally settle down and work together?
Unfortunately, no. Virtually no two different 433 tags work with each other’s system. With the cross-breeding begat by licensing, that can get pretty confusing.
The intention of a standard is true interoperability; but a standard alone does not ensure that goal. You can comply with a standard, yet not be interoperable with another product that conforms to that same standard. Makes no sense, does it? But it’s true. After all, interoperability that works across the board is the only means by which an emerging technology can drive down prices and drive up adoption. Who will make this happen in the active RFID space?
The ISO 18000-7
We must first turn to the only flag planted in the ground; and that is clearly the ISO 18000-7 standard, at the 433.92 MHz frequency. It is what the Army requires. It is what the 80 ports under Savi Networks control require. The giant prize of Active was always the U.S Army contract, which Savi Technologies had wrapped up for years. The story has often been written, Savi used 433 to set up their global military supply chain solution.
But was it really 18000-7 compliant? As it turns out they had been using a different protocol than 18000-7 specifies. Oops. Now they must retrofit much of the massive, global system to make sure the largest Active installed base is ready to become the backbone of a standardized network. As I reported in a past column, Savi has come on strong in allowing others to use their IP at preferred rates, in order to open the market.
No matter the frequency or application, Tags and Readers are the basic ingredients any successful RFID rig. But just as with the razor industry, where I am unable to buy Gillette blades to use with my Schick razor, one source’s active RFID tags do not necessarily work with any other source’s RFID readers, even at the same frequency.
Years ago when I jumped into the active RFID field, it was simpler. RFID was not yet the buzzword so everyone did as they pleased. The FCC Part 15 of the ISM band range opened a relatively wide band of frequencies to everyone. Axcess was successful using the 315 MHz frequency and RF Code was lighting them up using 308. Everything worked great on their own and things were good.
Now as more and more companies are learning the benefits of this technology, interoperability looms larger on the horizon as an essential goal.
Do not count on interoperability, even in 802.11
Okay, so the mere adherence to the ISO 18000-7 standard protocol does not ensure true interoperability. But it is easy to think that wi-fi is wi-fi, right? After all, that is the same communications technology that the 802.11 protocol, 2.4 GHz frequency of active RFID uses. So if you have those same wi-fi nodes receiving signals, regardless of whether AeroScout, Ekahau or other tags are being used, you would expect them all to work together, wouldn’t you?
Not so fast! It is not just the 18000-7 market that has problems communicating with each other. The 802.11 guys all use the same readers for their tags (network wi-fi access points) but they each use different middleware to communicate to the wi-fi access points. Mixing and matching tags at this point is a no-no.
Sure enough, this will change soon, because all of the market incentives are in place to ensure that. But while we are waiting, when it comes to how a tag speaks to a reader and how that reader interacts with a full feature set of application software, you want to ensure you hold all the cards. Make sure you test every combination of factors that relates to your business.
You must consider these questions to be sure that what is being implemented today will serve you tomorrow:- What is your provider’s commitment to new standards that may be developed?
- Make sure your contract includes a provision that if standards or market factors modify the common usage of the technology you are installing – be it 802.11, 433 or UWB – that your provider will ensure interoperability at no cost to you, either by retrofitting or through other means. Spell out the exceptions.
- What is the commitment of the manufacturer of your system to work with other companies? Who are they working with now?
- Whose protocol is being used in the system you are purchasing? Is it licensed from another company? What other companies have licensed the same technology?
- Conversely, if they use their own IP, who is licensing this from them? If they have a unique protocol with no cross-licensing, you may end up odd man out in the future. Of course, in a closed loop environment with a solution that suits your company perfectly, does this matter?
Last edited by AndyKowl : 03-23-2007 at 12:07 PM.
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