FCC Rule Cuts Bandwidth For 72-Mile 802.11b

sonamchauhan writes "This Computerworld article reported a 72-mile 802.11b wireless link (discussed in this Slashdot story). Now a Computerworld followup story is reporting the link power has been reduced by 75% to comply with FCC regulations for the 2.4-GHz band -- reducing the link's throughput from 1 Mbps to 300 Kbps. The owner is reported saying that: "any violation of the power limits was unintentional and resulted from the fact that the personnel working [on it] primarily have expertise in computers and not radio technology.""

Comments

Told you so.

[GigsVT]

To all the people that flamed me in the previous story for pointing out they were likely violating FCC regs, bite me.

People just couldn't fathom that college professors might not know what they are doing. Credentialism at it's worst.

Re:Told you so.

[Reality Master 101]

Isn't what goes on there just as "real" as what goes on in your office?

Any place with a concept of "tenure" has no relationship to the "real" world.

Just for the record, I agree with the guy. Not all college professors are clueless, but there is much, much truth in the old adage that "those who can, do. Those who can't, teach."

Re:Told you so.

[susano_otter]

If by "credentialism" you mean "trusting an entity because of its credentials, rather than your own empirical proof of their trustworthiness, it depends. If the accrediting agency is known to be trustworthy, then entities bearing their credentials will, on the whole, be more reliable than non-accredited entities.

For example: the Underwriters Laboratory. That "UL" tag on your microwave saves you the trouble of having to do your own exhaustive research on the manufacturer, plus thousands of man-hours testing each and every component many times over, just to make sure you're not buying a Deadly Microwave Oven Of Death.

Of course, if you feel that credentialism is always bad, then you should probably evacuate your home, spend 20 or 30 years teaching yourself how to properly test home appliances (don't forget to start from fundamental principles, since you can't rely on anybody else's knowledge or expertise to help you speed up the learning process), and then go in and personally validate every electrical device you own. And you can give up selling your expertise to anybody else, since we have no reason to trust your own self-accreditation.

I find it easier to research the trustworthiness of a few accrediting authorities, than to personally confirm the trustworthiness of everything around me. If the UL says it's safe, then those credentials are good enough for me. If the Elbonian Toursim Agency says it's safe, I'll want second opinion, though.

What the link is used for:

[dagg]

The link is used to carry data from a seismograph, data logger and Global Positioning System receiver. It cost about $3,000 to build and install.

For that type of data, I would imagine that the reduced bandwidth will be just fine.

Re:Why? Because.

[susano_otter]

The government doesn't "own" the radio spectrum; it regulates it.

In theory, the government's power to control the "airwaves" was granted by the people, by way of their elected representatives--you and me, that is (or in this case, our parents and grandparents). In practice, of course, giving and taking power from the government is much more complicated and frustrating.

The reasons for having a regulatory body for the radio spectrum should be obvious. The best reason I can think of offhand is airplanes. Airplanes rely heavily on communication via radio waves for safe and accurate travel. If there is no regulation (which might be though of as standards + enforcement), then no airplane can know with any certainty any of the important information:

What band to use to communicate with air traffic control?

What band to use to communicate with guidance beacons?

What band to use to communicate in an emergency?

Assuming you've got a good idea of which band to use, how can you guarantee that any of these bands will be available?

Will the guidance beacon band be overridden by a nearby private transmitter?

Will pranksters or malefactors transmit false traffic control instructions over the air traffic control band?

Will high-powered transmissions from nearby (unregulated) transmitters inadvertently disrupt the plane's avionics during takeoff or landing?

Without standards that everybody agrees on, and without proper enforcement of these standards, air travel would involve crashing planes into buildings on a regular basis. And that's just one of the many reasons why regulation is a good thing.

Transmittors who think that regulation is an "opt-in" thing, and that they're somehow entitled to ignore it if they want to, ruin it for everybody else. Every use of the radio spectrum that you enjoy in your daily life is made possible by regulation. It's why your cellphone doesn't pick up Mexican radio stations. It's why your radio-dispatched taxi arrives on time to pick you up. It's why your satellite TV gives you a clear image, without static from nearby 802.11b nodes.

Nobody "owns" the radio spectrum, but we all use it. Regulation helps make sure that it remains useful. You and I probably agree that the regulations aren't always beneficial to citizens, but ignoring them won't make things any better for anyone.

If none of this is obvious to you, then how can we possibly trust you to voluntarily play nice with others? And if we can't trust you to play nice, then we're left with two options: abandon any hope of ever using the radio spectrum for anything at all, or else enforce the standards and keep the spoilers out of the spectrum.

Which option would you vote for?

Re:Restrictions have reasons

[WolfWithoutAClause]

One issue is that satellites see the signal; there's always a little power transmitted into sidebands; and if the sideband lines up with a frequency that satellites use, then they can be in trouble. As WiFi becomes more and more popular this is going to become more of an issue.

A nice EM pulse or two. . .

[Fantastic Lad]

I think I'd like to spend some time trying to come up with a system designed to fry computers belonging to all the twits who are filling our collective air with their high energy EM pollution.

Directional, non-directional, I don't care too much. I want to be the guy with the portable EM Pulse generator. You like EM? I'll give you EM.

People seem to take pride in saying things like, "I'm useless without my cell phone and PDA!"

And you're pretty useless with it, too, actually. Stick a joker like that in a forest with a knife, two matches and a fishhook and see how long he'd last. Pathetic, or at least the precursor to something terribly Darwinian in scope. . .

-Fantastic Lad "--Look Ma! 5000 fried cell phones and their owners wandering around like so many headless chickens!" "Stop teasing the sheeple, junior."

Re: a bit off topic

[phoenix_orb]

DSL is limited in the United States due to concerns that the signal will bleed over in legacy telco equipment, thereby rendering many older phone systems obsolete. The baby bells wanted to push this regulatory measure through to enable her to make all equipment, even older Phone systems, work with the extra measure of having DSL on the line.

Keep in mind that most DSL equipment actually operates several thousand hertz higher than what you can physically hear.

It is quite all right though, as I worked for a DSL acompany, I got to test equipment. Imagine pure internet joy at 3 MB up and down with a class C of Public IP's :) (Two DSL lines channel bonded together through a netopia router)

2.4GHz in the US

[MaggieL]

In the US, the 2.390-2.450 allocation belongs to radio amateurs, who are using at least some of it to receive to weak signals from the AO-40 amateur radio satellite. Owners of unlicenced (Part 15) devices are requred to cease operation immediately if they are causing interference to licenced users, even if their equipment is unmodified, within power limits and type-accepted.

Signals at this frequency are highly directional, and if you interefere with an amatuer satellite operator, you can expect to hear from them. They know who to talk to at FCC about enforcement, too.