For Want of a Better Glue

As anyone who has sat in line at bridge or turnpike tollbooths knows, one of the truely great conveniences that tech in general, and wireless tech in particular, has brought us is fast-tags, k-tags, fast-lanes, or whatever they're called, wherever you are.

You know. Those RFID-based electronic toll collection devices that operate via an RFID transponder (tag) attached to the inside of your windshield. As you pass through a designated lane, a green "Thank You" light flashes, verifying that your transaction is approved and charged to your credit card.

So there I was, on the way home from YAT (that's "Yet Another Trip") late at night, when I came to the tollbooth that let me on the turnpike. But as I approached the gate, the light was stuck on red and the gate didn't rise. Looking at place where I expected the transponder to be, all I saw was glue where it had been attached. It had came unglued during my week away -- and I was coming unglued by the line of honking cars behind me. Then for whatever reasons, the light went green, the gate went up, and I scurried through like a Sea Biscuit running a race.

Of course, I did pull over to find the missing transponder and reattach it to the windshield, preparing my story for a state trooper, had I been pulled over, and if not, to the person in the tollbooth when I got off the turnpike. But when that time came, I drove right on through the exit, green light and gate cooperating to the max.

Curious as to what was going on -- not to mention wondering what my bill might look like -- I called the turnpike authority the next day to inquire and explain. As it turns out, the toll gates will always go up as you enter the turnpike, no matter if you have a transponder or not. This is simply a means of saving gates for those people inclined to drive through them. As for exiting, the system recorded my account number as I went through, not knowing where I got on the turnpike. In all likelihood, my monthly bill will have the maximum amount for the entire turnpike system charged, even though I got off at the first exit.

All in all, a reasonable system design it seems. The only problem area has nothing to do with the wireless technology, but everything to do with the adhesive material on the Velcro strips that holds the tag to the windshield.

Since we're talking RFID, it seems appropriate to mention RuBee, also known as IEEE 1902.1 -- an emerging standard that may be an alternative to RFID for some applications. RuBee networks operate at long-wavelengths and accommodate low-cost radio tags at ranges between 10 to 50 feet. The standard targets harsh environments, such as, I assume, the inside of my car. The RuBee radio tags, which will be either active or passive, would have battery lives of 10 years or more using lithium batteries. One of the advantages seen for the long-wavelength technology is that the radio tags can be low in cost, near credit-card thin (1.5 mm), and fully programmable using 4-bit processors.

In general, RuBee is seen as filling the gap between the non-networked, non-programmable RFID tags and high-bandwidth, radiating systems governed by local (802.11) and personal area networks (802.15). They are seen as having applications healthcare, agriculture, government and retail.

Okay, it starting to look like we have that wireless stuff down, time to go back and work on the glue.

Posted by Jon Erickson at 04:07 PM  Permalink