Radio-frequency identification
From Wikipedia, the free encyclopedia

Low-frequency (LF: 125 – 134.2 kHz and 140 – 148.5 kHz) and high-frequency (HF: 13.56 MHz) RFID tags can be used globally without a license. Ultra-high-frequency (UHF: 868 MHz-928 MHz) cannot be used globally as there is no single global standard. In North America, UHF can be used unlicensed for 902 – 928 MHz (±13 MHz from the 915 MHz center frequency), but restrictions exist for transmission power. In Europe, RFID and other low-power radio applications are regulated by ETSI recommendations EN 300 220 and EN 302 208, and ERO recommendation 70 03, allowing RFID operation with somewhat complex band restrictions from 865–868 MHz. Readers are required to monitor a channel before transmitting ("Listen Before Talk"); this requirement has led to some restrictions on performance, the resolution of which is a subject of current research.

Hi.

I'm Clodfobble's husband. For years now, she has participated in lively conversations with many people on the Cellar. Some of these interested me greatly, but for years now, I have never once posted, nor even really read the threads. I want to mention this to provide background and perhaps a little weight to what I'm about to say:

You, sir, are a moron.

My wife's post was was stating that TX Tag was an RFID device, which you dismissed because you were not personally familiar with TX Tag, but instead based your assumptions (a dangerous thing for an engineer), on the older EZ Pass technology. You stated that the reporter must be a "technically naive reporter", when in fact you were the technically naive one. A simple google search for TX Tag gave the Wikipedia article which validated the manufacturer as Transcore's eGo product. A quick click there gave the frequencies for these devices. You want to complain about the ranges? Fine. Go ahead. But I might note that the TX Tag is a passive 900Mhz RFID system, currently in use. I'm willing to bet that the engineers that tested the system are happy that the tags are responsive within a range acceptable for operation on the tollways (which are certainly greater than 3 meters, but probably less than 10). But then again, no one was asking about that.

It's OK to be wrong. Sure, it hurts your street cred a little, and all the younger engineers start eyeing you like they're going to challenge you for dominance in the RF engineering pack, but it's much less painful then continually driving the wrong point home over and over again.

So ends my first (and probably last) Cellar post.

Oh no, no, no, no. Please. Please don't make that your last post. Look, I understand the appeal of going out on top, but I urge you to resist that siren call. Please stay. Please post. Don't go.

Honestly, welcome to the cellar, Mr CF. Any friend of CF's is a friend of mine. I personally welcome your debut, and your rebuts (if any). Plus, we could use some more brains and wit around here, god knows I'm draggin down the curve.

Ok.

Well, I guess that covers it. Since the cellar is a community property cyber state, I think you can claim the spousal exemption to the test. Oh, and that was a great opening post. See ya round the rodeo.

TW was correct for the class of tags called passive, and that includes the mobile speedpass readers you can put in your car. Those use an antenna positioned above the gas pump to imterrogate the widget you're supposed to mount in a window. The NY/NJ/PA EZpass tags are active...they have a battery and transmit when asked to...gives them a lot more range. I'm pretty sure the Mobile speedpass car gizmos are passive. I use the keyfob one, and used to have a NYS EZpass. and I design stuff like this for a living.

In theory, you could get an RFID tag to work from many miles (think military radar which identifies targets from a long distance away solely on interpreting echoes, even when the object in question doesn't want to be identified.) The issue is only one of economics: power, range, number crunching, safety.

I have credit cards that are chipped, my company badge is an RFID tag, my cellphone reports GPS position to E911, and a 802.11 LAN can do geolocation if you program it appropriately.

remember that the only time time your cellphone or laptop is "off" is when you remove the battery..all other times they are exploitable by malicious code

I forgot...frequency selection is also economics and physics, there are no unique or optimum RFID frequencies until you start placing operating constraints on the system.

Welcome to the Cellar Mr. Clodfobble. :D
Thanks for the input. I could see why you would be reluctant to post here, or anywhere she knows about. She's a very smart chick and if you flub, she'd cut you to ribbons. That could be bad, when you just can't hit the close button to escape.
That said, your post didn't sound like one prone to flubs, so please resist the temptation to protect your genitals and stick around. Please.

Which was the point from the start. It is only a matter of time until the physics can be exploited to increase the range and power of the signal. In fact, it would not surprise me at all if it is not already been done.

OK all you experts, assuming the advances can be made to increase the range to hundreds of miles, what about interference? If you have a military theater of operations with 200,000 RFIDs all transmitting at the same frequency at a range of hundreds of miles, how will you not have interference? This isn't cars zooming single file under a reader, or jeans coming out of a store one at a time.

Could you have a reader that sends out a narrow beam and scans regions of an area, much like the ray of a cathode tube scanning the individual lines of the display screen? A big eye in the sky, slowly scanning the ground back and forth for individual RFIDs?

'We again have proof that Saddam had WMDs.'

If that product does exist as an RFID for monitoring cars through toll booths, then Mr Clodfobble could provide numbers or a citation. Currently we only have his emotionally laced insistence that it is true. And that is the credibility lesson from a lying president. One whose knowledge comes only from ‘I feel I know’ need not provide credible sources. Where are those facts and numbers? Why so much emotion when simple citations could have answered the question?

When numbers suggest it does not exist, does Mr Clodfobble provide numbers and citations - or get emotional?

I did his work. Some new RFID electronic tolls booths in the UHF range work reliable if the vehicle stays under 20 MPH. RFID was not the point. Mr Clodfobble made claims without providing one reason to believe him. That should never happen now that we all learned why a mental midget president could lie same way about WMDs .

Clodfobble finally provided a citation only after being pushed. Numbers in her citation said RFID still is not sufficient for tolls booths. She did not do the required work - cite those numbers. I had to find numbers from her citation. Clodfobble was called on making claims she could not even confirm with underlying facts or a grasp of the simple technology. Her proof was same that a president used to prove Saddam was importing yellow cake from Niger.

Get those simple facts was not difficult. RFID for electronic toll collection is a recent achievement that requires a vehicle to pass through slowly. That information was available at responsible sources such as RFID Times Magazine. Only required was something to make Clodfobble's post credible. So why so much silly emotion?

Amazing how many still want to believe the first thing they are told rather than demand confirmation - the numbers. Amazing how many get childish emotional when they don't provide necessary citations.

"Mission Accomplished taught everyone this: "I know only because I 'know' means I know nothing". Attached emotion only implies a credibility problem. Basic facts were so easily avaiable. Why instead so much childish emotion?

There are numerous solutions to this problem. Ethernet demonstrates one using collision avoidance. Two common solutions include time domain and frequency domain multiplexing. AT&T cell phone systems used frequency domain multiplexing. Other better systems use time domain multiplexing. Another is Wide Band Spread Spectrum broadcasting. A technology originally patented by Hedy Lamar in the WWII era. A technology that probably should have been appearing in a scaled down version in Version N of Wifi.

Also useful are antenna polarity. This is why satellites with only 12 frequencies (channels) can operate 24 transponders on those 12 frequencies.

Obviously is antenna gain. MaggieL posted pictures of her satellite directional antenna - a yahgi. I suspect it is so directional as to require adjustments to within single digit degrees.

And then we go back to Shannon's 1940s theories on communication. How to cut through the noise? Two methods. More power or slower data rates. Today those revolutionary concepts should be common knowledge to the computer user.

See, that's how they get you. "Bit unhappy" over chipping animals, but totally thrilled when it's "for the children."

In most cases, the pet-based uses are pushing you over the edge of the slippery slope that will end up in mandatory human use. There will be some side-trips to chipping criminals, probably, maybe even including seeing to it that they are all entered in a DNA database ...

It's not paranoia when it's real, people.

I don't know where you got 20 mph. I drive under the toll archway every single day at 80 mph. It scans my windshield tag and sends me a bill.

Actually, I provided a second and third citation after you accused the first one of being untrustworthy.

Ah. So first, I must be wrong because my tag has a battery, I just don't know about it. Oh, turns out it really doesn't have a battery.

Then, I must be wrong because the range of the tag is too small for a toll booth to read it as I pass by. Oh, turns out the range is at least 10 meters, maybe as many as 30, and my state's archways are about 15-20 feet over the roadway, well within range.

Now I must be wrong because I didn't mention I have to drive 20 mph through the tollbooth. Can you guess what's coming, tw? Oh, turns out you're still wrong, traffic does not slow for pre-paid TXTag customers. Your "responsible" source is either inaccurate or out-of-date, much like your original technical citation from 2005.

Clod, just because the thing works, doesn't have a battery, operates at an impossible range and at unrealistic speeds doesn't mean that you still aren't wrong, you know. :eyebrow: