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White Spaces Test "Rigged," Says Google Co-Founder Page
Davide Marney writes "As reported by the Washington Post, Google co-founder Larry Page claims that an FCC field test of white space wireless devices was 'rigged' to make the test device fail to detect wireless microphone broadcasts. A Google spokesman explained later that testers had hidden the wireless microphones within the same frequency as local television stations, preventing the test device from detecting them."
It's great to hear debate on this issue... but this is a scientific issue, and we should test it with science. Google is a big company. They should conduct their own experiment and publish the results if they want to refute the FCC test.
If you had super powers, would you use them for good, or for awesome?
I'm usually a huge fan of google, but in this case, I'm on the side of the entertainment industry because I work in it and already with digital television vs analog we're gonna have a harder time finding open frequencies (and some events have been known to have 40-80 or maybe even more wireless microphones).
There is no such thing as "hiding the wireless microphone frequencies in local tv stations" that is where they live. The problem is the FCC hasn't given us our own frequencies to play with so we have to work around and in the TV channels.
And now he's walking a line dangerously close to slander.
If he's wrong, he's going to have a lot of lawyers climbing into every orifice of his body.
"He can't be wrong!" you say? Go ahead, believe that. He's hardly an impartial observer.
... because for someone who hasn't been following this in detail, TFA doesn't even make clear what exactly Page is claiming happened.
Larry is an executive at the company that's claiming it was held to an unfair test. You think Google doesn't employ radio experts who could have told him what to say?
Oh the conspiracy of it all!
Next they'll be rigging voting machines
Oh wait . . .
--
Oh well, Bad Karma and all . . .
Beer is proof that God loves us and wants us to be happy.
the last thing the established broadcasting players want is more competition
Perhaps he might be talking on behalf of his company? I heard that Google actually have a R&D department, who would of thought?
From what i gather, hes claiming they tuned the microphone detector at the same frequency as a television station, effectivly drowning out the microphone.
I really, really don't like whitespace devices.
Companies like Google claim it will allow internet access in rural areas; that's also what they've said about BPL and WiMax and we see that those are being deployed mostly in major cities. The difference is that this time, there's no gain in major cities. (This is so much like BPL it's amazing, able to stomp on everything that's supposed to be in the band, not really benefiting anyone who's supposed to be benefited by this, etc.)
With digital TV coming, white space devices are a very, very bad idea. These devices can start transmitting and wipe out a digital signal, and then how are you going to know what's causing it? At least with analog you could look at the noise in the picture and get some idea of what's causing it. I know they're supposed to detect interference, but as anyone with a cell phone can tell you, dead spots for UHF can be very small and the device could pick what looks like an "empty" channel only for it to be the same as a local TV station.
I'll admit I'm biased in favor of over the air TV, but unlicensed white space devices are a really bad idea. If the FCC wants to license them to allow them to use TV spectrum, that doesn't bother me, but a free-for-all is a terrible idea. In fact, there was a company that did something like that, used a TV license from the FCC and did internet service with it, I want to say it was in Houston. They went out of business, I believe.
I generally like Google, but I am in complete disagreement on this subject.
Here's the summary:
There's unused radio spectrum (called "white space") between the TV channels that are designed to give the stations protection. Google (and others) claim that small radio devices can transmit on those frequencies and not harm the TV signals, TV stations of course fearful of anything that might cost them viewers disputed that.
So the FCC set up a field test of a Google device and other devices to see if everything work right. The result of that test was a "fail" for Google's side... but the news is that Google is claiming the wireless microphone channel being tested equated to a local TV broadcasting channel, and therefore was unfair.
I'd also say that the same applies to any other discipline. If you see a flaw in someone's argument, call them on it. People are human and do make mistakes. And amateurs have access to information that many professionals would have killed for even a few years ago.
Now, this doesn't mean that a doctor or other expert has to listen to every crackpot, and that every amateur ought to be given the same weight as a noted expert. Sometimes, the proper answer to a question is indeed "Stop wasting my time." The trick is to know what time is when.
Those who can, do. Those who can't, sue.
Summary for non-engineers:
Google (among others) want to use the newly freed analog TV frequencies to provide long range wireless internet.
Short range RF microphones i.e. wireless stage mics that aren't using IR currently operate in this area as well. current analog TV doesn't interfere, I'll spare details.
Some claim the wireless internet system that has been devised will interfere with these microphones. Google group says they won't because the devices are capable of detecting a microphone transmitting and work around the issue (change freq).
FCC setup a test, device failed to avoid microphones frequencies thus, knocking it out of commission and failing the test.
Google chap claims the testers had the mic transmitting on a frequency used by the local TV channel and this transmitter was so strong that the system could not detect the microphone because it was effectively masked.
Google chap says this was done on purpose.
The end.
into English?
that's exactly how wireless microphones are deployed in the field.
In heavily saturated markets, the wireless mic frequency may sit between a TV video signal and the same channel's audio signal.
At least until things go all digital, then audio and video are muxed into one square wave leaving no room to stick a mic signal. This exasperates the dilemma facing wireless mic operators.
And yes that little PDA can easily wreak havoc on a Broadway show, NFL broadcast or any other production. That's why we regulate the spectrum...devices operating on the same frequency will interfere.
Google spokesman explained later that testers had hidden the wireless microphones within the same frequency as local television stations, preventing the test device from detecting them.
Hey, can I get one of those? That might be fun to play with:
"Hey there Lane, I know this is a little awkward, me being a cartoon and all, I was just wondering how you'd feel if I took out Beth." -- Bernard "Barney" Rubble
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
What we're hearing about now is outrage over test results which have not yet been published. When they are, they will "show" that wireless Internet devices that Google is trying to get accepted by the FCC were unable to detect a wireless microphone. We've supposed to then believe that the wireless Internet device, having failed to detect the microphone when it checked that chunk of the spectrum, would then begin transmitting on that piece of spectrum, thereby disrupting the microphone. The sound bite is "device which fails to avoid interfering with wireless mic is bad and will not be allowed."
It takes only a moment to see that it was a rigged test because the wireless Internet device did NOT interfere with the microphone, because it did successfully detect the local television station that was broadcasting on that frequency and therefore did not try to use it. Analog TV stations are some seriously high power broad spectrum noise. Any frequency-hopping wireless Internet device would be useless attempting to use the same frequency and would obviously move on to another part of the spectrum, thereby avoiding interfering with the TV station and any other device being masked by it. That part will be conveniently left out of the headlines. The fact that the wireless microphone itself may have been useless while attempting to use that frequency, due to interference from the television station, will also be left out.
So basically the rigged test will be used to deny Google's hopes of fielding devices to use unused spectrum, thereby maintaining the television broadcast industry's lock on chunks of spectrum that they're not even using. It's an inefficient waste of spectrum that dates back 50 years to the days of radios that had just enough vacuum tubes to put a signal into the air, and had none left over for complicated automatic frequency usage detection algorithms. Nor had the Ethernet exponential back-off anti-interference algorithm been connected to the problem. The regulatory regime is antiquated, but the entrenched corporations that have a vested interest in spectrum are defending what they see as "their" airwaves merely on principle.
It wouldn't take a working group all that long to come up with new technical requirements that could be used as FCC regulations that would make use of ALL allocated but unused licensed spectrum, without ever interfering with older dumb devices. Software radios that receive before broadcasting, analyze the results, move on to another frequency if usage is detected, exponentially back off that frequency if it's still in use the next time around, transmit only during some defined time slice, and never broadcast more than 1 watt of power could use that spectrum without legacy device interference and without mutual device interference. Google knows it. The TV industry knows it. The TV industry feels besieged after having parts of spectrum that has been their exclusive stomping grounds for decades sold off to the highest bidder while they get squeezed into digital broadcasts. Google claims they're pulling dirty tricks to defend the spectrum they have left. Just sitting here looking in from outside, I have to agree.
Dude, you're arguing with yourself, get help!
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
Vested interest does not necessarily lead to bias, though it certainly could have done so in this case.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
When I saw the "white space" being rigged reference I was expecting some election cover-up story from some red state in the bible belt.
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It takes only a moment to see that it was a rigged test because the wireless Internet device did NOT interfere with the microphone, because it did successfully detect the local television station that was broadcasting on that frequency and therefore did not try to use it. Analog TV stations are some seriously high power broad spectrum noise. Any frequency-hopping wireless Internet device would be useless attempting to use the same frequency and would obviously move on to another part of the spectrum, thereby avoiding interfering with the TV station and any other device being masked by it. That part will be conveniently left out of the headlines. The fact that the wireless microphone itself may have been useless while attempting to use that frequency, due to interference from the television station, will also be left out.
The test is not rigged. I have been doing RF coordination for entertainment professionally for about a decade now and I can assure that with this test the FCC has highlighted one major strategy that we use in crowded RF environments.
An analog television station is not the high power broadband noise machine you make it out to be. An NTSC analog signal takes up 6MHz of bandwidth in the radio spectrum. That signal is actually made up of three distinct signals that are modulated into one channel; those signals are a video carrier, a chromance sub-carrier (color) and a sound sub-carrier. Those signals take up a few 100kHz of bandwidth and are separated by a few 100kHz.
The standard RF microphone used for stage, television and film production has a peak bandwidth of ~ +/- 56kHz or a grand total of ~112kHz total deviation. With that small usage of bandwidth we can fit three microphones into an operating analog television channel without causing interference to the primary spectrum user.
The FCC test seems to be showing that Google's engineers are unaware of this strategy employed by RF coordinators and that if their device decided to employ the same strategy, it would interfere with the operating microphone within the analog television channel.
Mind you, this becomes moot on 19 February 2009 as we cannot do this trick with a digital ATSC signal. That is the high-power noise generating machine you are refering to.
-e
You are going to trust an R&D department that can't get any of their products out of beta? Silly person.
In heavily saturated markets, the wireless mic frequency may sit between a TV video signal and the same channel's audio signal.
At least until things go all digital, then audio and video are muxed into one square wave leaving no room to stick a mic signal. This exasperates the dilemma facing wireless mic operators.
And if the wireless mic being tested was sharing a channel with an ANALOG TV transmitter the test was totally bogus: The situation they tested would no longer occur after Feb '09 because there would be no more analog TV signals to confuse the whitespace device.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Fuck the wireless mics. Get rid of them and put them in their own set of frequencies. This is much more important.
Bill Clinton: Pimp we can believe in. - The Shirt!!!
FTFA (hiliting mine) "The FCC's wireless microphone field tests were carefully planned and thoroughly executed based on sound engineering science and real-world operating scenarios. These tests were open to the public, and those who choose to discount the results -- which have not yet been published -- had every option to be present and to witness them for themselves."
Ya gotta learn how to play the game, this is gov't after all guys and apparently you didnt lobby quite enough for this.
The white space between channels can be used by auto-tuning software to determine where the channels are by detecting energy levels. Fill the white space up and this sort of auto-tuning cannot work. Modern digital tuners probably don't need this, but older, cheaper designs probably do.
Engineering is the art of compromise.
FAIL!
There will be no full power analog TV broadcasters, but the transition date of 2/17 does not apply to -LP, -CA and translators.
Where they trying to show that the Google device did not interfere with the microphone? But if it was at the same frequency as a local TV station, it would have not worked whether or not the Google device was on - the TV signal would have interfered.
If, on the other hand, the Google device was designed to avoid populated spectrum, it would have avoided that frequency in any case, assuming this feature worked at all.
So exactly what was being tested and what was the failure mode?
Squirrel!
How could that possibly be a mistake? How could the FCC not know that when it tested? Is this a new test or something?
Then, given that all you'll have to work with is an impenetrable square wave, and given that the FCC knows this, what is the purpose of demonstrating that you can play funky tricks by squeezing a microphone into space that will no longer exist? How can it be anything other than rigged? You said yourself this trick will not even be possible in just a few short months. How is a test that tests an environment that will no longer exist anything but a con job? My definition of "rigging" a test is creating a test that is not a faithful representation of the actual operating environment to the detriment of the applicant.
I know, I know, never attribute to malice what can be explained by stupidity. So some idiot designed the test, thinking he was being clever, when it had nothing to do with the environment that will pertain by the time any action could be taken to approve whitespace devices.
I still say that the Google devices checked for signals right where the 6 Mhz of spectrum was supposed to be in use, and immediately moved on, chalking off the whole block as occupied. Why check further when the licensed user is very much clear and present? It doesn't even require naivete to make that decision. It only takes a conservative engineer. Just because people like you are willing to squeeze your signal into that occupied frequency doesn't mean they were. (I don't mean that pejoratively. I'm referring to you as representative of your industry, representing long-established practice.)
And you and I both know that the theoretically lovely 6 MHz NTSC analog signal gets bounced around by structures and atmospheric effects until it gets smeared across 20 MHz or more. The buffer zone built in to the 6 MHz allocation has never been enough to prevent signal bleedover into the space of other stations.
RDF techniques? I thought Google was making this, not Apple.
I am the Game-Day frequency coordinator for a major-league sports team (contractor to the league). Some of my colleagues were in on the test and I have read their individual on-field reports.
My recollection is that a good many of the WM's tested in this experiment were in "good, clean whitespace." Let's think it through - a WM hidden in an occupied analog TV channel should be protected by the much stronger carriers of that station. If the whitespace-using net gear is equipped to use such small interstitial spaces as WMs use, it should be sensitive enough to detect WM carriers therein.
I suspect Mr. Page's remarks are fed by a badly underling-filtered early version of the report (or leak).
Thank you, great sir. This should have been the summary for this article. It's a lot clearer than what's up instead. In particular, it provides context, makes it clear who says what and why, and keeps things in logical order. An example that the editors would do well to follow.
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The impression I got from looking at the tests that the FCC did to select 8VSB over COFDM and make the US different from the EU and JPN in digital TV standard was rigged too.
The new ATSC standard is dire in urban situations where multipath is a major issue. COFDM is miles better, but would have promoted a more decentralized infrastructure and lessened power of the legacy broadcast lobby, so we're stuck with shit.
I cannot speak for the FCC's motives in devising the test the way they did. Certainly the test is designed around conditions as they are, or more accurately, as they can be and not how they most likely will be in the future.
I would imagine that your characterization of some FCC guy thinking that he's being clever is probably right on the mark. The FCC knowledge tests are full of this "clever" thinking. Both the amateur and commercial radio tests have trick questions and what ifs, as well as lots of out of date questions. There is no reason for me to think that they wouldn't do the same thing in a practical test as well.
IE: in the current commercial GROL exam there are several questions relating to the OMEGA navigation system. As of the end of this month that system will have been officially deactivated for 11 years.
All that said, I still don't believe that the test was rigged as it is representative of possible current conditions. The FCC may have been trying to make a point that the designers of the white-space devices need to think a little more outside of the box as to what might be using apparently free spectrum, or where there might be available space in apparently used spectrum. There might be a wireless microphone there or there might not. The trick of putting low power transmitters inside an operating television channel is one of last resort. At the same time one also never knows when a HAM radio operator might pop up.
However, I would allow that the test is disingenuous in that it is not likely to be representative of the conditions that the white-space devices should encounter when the would be authorized for use. Using that criteria (current / obsolete vs expected future), I understand your contention that the testing was rigged.
-e
Uh, dude, it's never R&D's job to get products out of beta.
Actually, the fact that so many of R&D's betas are used as end products by the masses just goes to show how exceptional their R&D really is. Most R&D departments do flimsy prototypes and call it a day. It's up to engineers working on a production system to bring something out of beta, kthx.
This is exactly how spooks and the like hide a microphone (bug).
The best way is to have it transmit within the exact same frequency or spectrum that another service uses.
If you use low enough power for your transmitter, you minimize collateral receivers being able to pick your signal up, while at the same time making it near impossible to track or find the bug.
Google's guy is just pissed he got one-upped. The FCC did this entirely within the realm of what would happen in the real world.
Sometimes it sucks to come out from behind the keyboard and discover real world stuff, huh?
--Toll_Free
The problem is they are covered by part 95. Part 95 states that the device must A. Accept any interferience, and B. Must not cause any.
Hence the reason it gets tested in "real world" conditions.
--Toll_Free
"And you and I both know that the theoretically lovely 6 MHz NTSC analog signal gets bounced around by structures and atmospheric effects until it gets smeared across 20 MHz or more. The buffer zone built in to the 6 MHz allocation has never been enough to prevent signal bleedover into the space of other stations."
Your comments needed to stop before this, because you showed your own ignorance of how radio and the spectrum works.
The only thing that can cause a signal to "increase", as you put it, after modulation and transmission is to have something rectify it and reradiate it. If that's the case, it isn't the TV stations (transmitter) fault, it's the problem with the device rectifying the signal.
But, to state that the radio signals get bounced around and end up occupying more bandwith is stupid, ludicrous and ignorant. Yes, signals get bounced from once item (building (dependant on frequency), ground, mountains, etc) to another, and they change POLARITY, but it has absolutely NOTHING to do with the occupied bandwith.
The bandwith wasn't enough because they amplitude modulate the TV signal, and it causes problems with IMD by it's nature.
--Toll_Free
I don't really see what Google has to do with this, other than that they (along with Microsoft and who knows how many others) want to be able to make a fast buck out of broadband access, whether directly or indirectly.
But these whitespace frequencies have been used for a significantly long time for devices such as wireless microphones. Just because Google has bottomless buckets of money doesn't give them any claim on the frequencies.
I too would suspect that a device capable of using the interstitial spaces of an active channel would be capable of detecting an RF microphone but I don't know what the FCC wanted Google's device to do. Was it supposed to simply stay off active transmitters or did they want it to flag any and all transmitters in the pass-band?
I've only heard third-hand reports of what happened at the test as the results (to my knowledge) haven't been made public yet. Judging by the article, your comment, and a large amount of wild-ass guessing on my part I would imagine that the FCC wanted them to flag anything and everything in the pass-band but that Google's device saw an active television channel, noted it but didn't analyze it's interstitial spaces, and moved on.
That could be good as that could say that the device would not attempt to use small gaps between transmitters in a crowded RF environment. However, that would seem an odd outcome for a device that (I assume) is designed to take advantage of those same small gaps.
On the other hand, it could be bad as that could mean the device does not perform due diligence in seeking low power transmitters.
Without knowing the FCC's intentions, it's hard to speculate.
On a personal note (apologies as I couldn't help but checking out your call-sign), your name seems familiar and I think we've worked together (or at least met) previously but I can't place where. Did you ever work for PWS or with Stoffo?
-e
Google is advocating wireless Internet. The FCC were trying to receive signals from a wireless microphone and didn't succeed. Why does Google care? ? WTF
These tests were on digital signals not analog, so your correct when you said this is moot. The whole purpose of these tests are for working in digital TV bands because thats the future of TV transmissions. So of course the participants wouldnt worry about doing this in the analog bands.
We're not talking about setting up a machine that sprays toxic waste into the atmosphere or some sort of plant that will poison groundwater supplies, we're talking about setting up a goddamn broadcast antenna. Just like the ones Mexicans watch TV on currently. The original poster's point was that since the agency that decides whether or not you can SET UP broadcast antennas in the US is also the one that's being accused of RIGGING the test and LYING about the results, you'll have to find somewhere else to set up your antenna.
So take your trumped up "disgust" and stick it in your self righteous ass.
Maxim: People cannot follow directions.
Increases in truth directly with the length of time spent explaining them
Diebold Accidentally Leaks Results Of 2008 Election Early
Sure thing, Larry. (j/k)
But the Google device will *not* use the same strategy. If there is an operating analog or digital TV station, the device will *not* use that frequency. So it's irrelevant whether or not the device can detect mics on the same frequency as a TV channel. As long as it detects one or the other, it won't interfere with either.
I probably don't have to tell you this, but it's worth pointing out anyway that the *vast* majority of wireless microphones are actually technically illegal. Unless you have paid $75 to the FCC and been granted a license, you are using wireless microphones illegally. The fact that the FCC chooses not to enforce this, but comes down so hard on white space devices, is really a double standard.
main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
It's up to engineers working on a production system to bring something out of beta, kthx.
That would be the "D" component of R&D.
Filter error: Please use less whitespace.
I am well aware that on a nightly basis I oversee the operation of nearly 75 illegal radio stations. Unfortunately, the FCC has not seen fit to provide a way for me or my colleagues to operate legally.
The only entities eligible for licenses for the operation of wireless microphones are news gathering organizations and film producers. This policy leaves out live entertainment which are the vast majority of users. Any time you see a concert, theatrical production, sporting event, or even a political rally, if those microphones weren't provided by a news organization or film crew covering the event they are being illegally operated. Any time McCain or Obama gets on stage with a wireless mic to address the crowd, or a coach calls a play to a quarterback via wireless intercom, those are all illegal uses of wireless microphones. The President doesn't break the law because the Secret Service doesn't trust wireless microphones (or even phantom powered mics for that matter) and so he has two wired Shure SM57 microphones on his lectern. Rest assured, it's not because he can't get a license (though technically he can't).
The FCC turns a blind eye to our usage for the most part because we try very hard to be good neighbors. If any issues arise, we are the ones to move or cease transmission. We do our best to not cause interference to any users because we have no legal standing to operate; and we cooperate with our fellow colleagues so that issues are worked out amongst ourselves.
You are right in that there is a double standard. The difference is that at the end of the day, I and my fellow operators are watching to make sure that we don't cause problems and to proactively keep things that way. The average user of a white-space device cannot be expected to exercise the same due-diligence so the FCC is insuring that the devices do the work for them.
Mis-diagnosis killed my brother. Seriously.
He was having pain in his left calf whenever he did light/moderate excercise. I don't mean running, I mean walking around the mall. He would cramp up after about 5 minutes, then when his muscle relaxed, he could continue walking for quite a while.
He went to at least three doctors and all three told him different things. 1) he just needed more exercise. 2) it was a torn or damaged muscle 3) he needed more potassium. This is in spite of the fact that he had the symptoms for three years before his death.
Actual answer: Severe atherosclerosis which lead to myocardiac infarction (heart attack), and death.
It was surprisingly easy to figure out from the symptoms and a few websites. I was shocked that none of them thought to mention the possibility, and that they all discounted each others diagnoses.
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New punctuation update "~" at the end of a line to indicate sarcasm. http://harns.blogspot.com/
that's a great idea ~
Easy fix, put the channels on YouTube or remove them altogether. After all what are the chances that they are broadcasting anything remotely interesting ?
May contain traces of nut.
Made from the freshest electrons.
Just a guess, as I've not read the article, or even all of the summary, but I'm guessing the device was supposed to "detect" the microphone, but didn't, cause the microphone was on a frequency the device was programmed to ignore.
Just a guess.
I'm not saying that an opinion should be solely based on whether or not an industry group employs unethical tactics like astroturfing, and not on the merits of each side's arguments; but if you did, you would side with Google. There are dozens of comments on the Washington Post page that are clearly (to me) part of an "online strategy" by those opposing opening up whitespace.
Does anybody know if this "Human Experiment" (http://humanexperiment.net/) has something related to Google? Several friends of mine have tried to find out the idea behind the site, but it's just too obscure!
That's the *development* of research ideas. It is not the *production* of research ideas.
Methinks you don't have a clue what R&D is about.
Doesnt that mean that Microphones would fail too, when analogue disappears?
Have a nice day!
And the FCC lost the Federal Court case that the ARRL initiated. What a bunch of crooks and cronies. They don't work for us, but just like the rest of the government, whoever brings in the biggest suitcases of cash.
Yes, great idea/home/zibri
White space is not defined as the small padding between documented frequencies, thogh a spall part of it exists there. White space are the UNUSED frequencies in many markets.
You see, there are more than 40 TV broadcast chanels available, and a further 81 digital channels as well, but in any one market or area, typically no more than 10 are ever in use. There is some small bleed over from one market to another, so maybe 15-18 of the channels may have some signal detectable and thus needing to be avoides.
Wireless microphones are poretty much the only other dev ice allowed to operate in this range. Where TV might cover 100 mile radius of effect, mics have at best a mile or so. There are a lot more of them in use, upwards of 40 for a single concert, and dozens at each TV studio, and your local bands and clubs each may use a few, but I know a few guys in bands, and they donlt seem to have any issues with signal crossover themselves when setting up their gear, so there are clearly not so many of these in use that it's a big issue.
a white space detecting wi-fi system would simply scan the spectrum and find a frequenct it detects no power on at all. Then, if it feels its safe, it powers on its anteanna and begins broadcasting, but that's not where it stops. Should it detect a signal after its picked one, its supposed to automatically fail over to a backup frequency (it also scanned for) and instantly stop broadcasting on the first until it determines the nature of that signal (perhaps it's just anotehr wi-fi base station that it can co-exist with).
Now, we're also not talking about using these things in home deployments. The purpose of this frequency is that it penetrates walls and has a significant range for a small amount of gain. Home users don;t need a wi-fi base station with a 5 mile radious of effect... This is for municipal deployment, large campuses, park areas, etc. Busineses won't use it because the range is so great, it's a security risk. In any geographic area, an ISP would deploy these things in a grid pattern, likely each 2-3 miles apart, so there's reasonable signal coverage even if one fails. This means at any one spot, an ISP might be using 5 signals, which I might add use a tighter digital signal range than TV, so 2 or 3 of these might take the channel space of 1 TV station. Maybe there's 3 or 4 ISPs in an area that size with simalar devices, so potentially we're talking 16-20 radios, which might use 20% of the white space in a given 5 mile radius, of which less than 20% more is in use by broadcast TV stations. This leaves 60% of the digital frequenct range for wireless microphones... 3 times what either TV or Wi-Max are getting. Why is this an issue?
Besides, for wireless mics, they can change frequencies! TV stations can't, but when your engineer powers on a mic, he checks for interferernce. If it's a bad, channel, he changes it. Once the mic is on, since Wi-max would not interfere, the only other potential for interference is someone else using a mic on the same channel. They're used to that. Even if WiMax was using the frequency when he turned it on, it would stop and the mic would get a clear signal unless another mic was also came on.
I think the only thing we might be able to propose is limiting wimax deployment into white space to a certain number of operating base stations on seperate chanels (some will be bridges on the same channel, so they don;t count). Say, limit to to 25 or 30% of the total available white space, and if it comes on and there's not enough, it should report an error. Again, this is limited to ISPs and big municipalities, so I really doubt we'd even hit this number of stations operating at once anyway.
There is no contest in life for which the unprepared have the advantage.
I think it was coined by Alfred Sauvy in the '50s. The third estate was, in the Ancien Régime, whoever was not part of the Nobility or Clergy; a mere 99% of the population. The Third World was whoever wasn't in NATO or Warsow Pact (nothing to do with New World / Old World).
What they are applying for patent is already present as a multi-billion dollar business in India.
The whole Mobile market in India is bases on this very same principle.
So why does your wish to avoid using a wired microphone trump my wish to avoid using a wired computer?
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
What happens when you set your WMs up for game night, and I set mine up for the concert across the street. You do your setup the night before, I do mine the morning of. Who should be allowed precedence? Who is at fault for the resulting interference? Why should my GooglePhone have the same rights to the radio spectrum as anyone's WM?
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
But what exactly is Google claiming was happening during the test?
My question is: Why does the entertainment industry get permission to broadcast in those "white spaces" when Google cannot? What is so special about a few pop singers that want to use wireless mics so they can shake their twat on stage that overrules the public good that whitespace spectrum would provide?
Most likely this is something the entertainment industry lobbyists have bribed the FCC to allow.
"When the president does it, that means it's not illegal." - Richard M. Nixon
Start test:
\n\t\r\n\t\t \t\t\n \n \t\n\r\n
End of test.
The FCC test seems to be showing that Google's engineers are unaware of this strategy employed by RF coordinators and that if their device decided to employ the same strategy, it would interfere with the operating microphone within the analog television channel.
IF. So does it employ that strategy — in which case it'd certainly be a gross design oversight to allow the device to drown out other devices on the same frequency? Or, as other people have pointed out, does it avoid using a frequency which is already being actively used, which would prevent it from interfering with either the TV signal or the wireless mic "hidden" between the TV carrier frequencies?
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Good point. The microphones in question will be banned from the new 700 MHz safety band after the DTV cut-over, and will be useless within used DTV channels. Paradoxically, the FCC docs clearly outline testing against part 74 wireless mics. How those two statements fit together I cannot fathom.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
Do the proposed white space devices actually use the unused spaces within an active channel? If so, that strikes me as poorly thought out since any transmitted signal would be right in the middle of a television receiver's passband and while the television channel may not be using that particular spot of spectrum the television receiver will still have to contend with a significantly higher dynamic range requirement. The requirements for that type of operation are so high that digital receivers without equal IF selectivity still can not match the performance of superheterodyne receivers when rejecting in band signals.
The only safe bet for a white space using device is to completely reject TV channels which are in use and leave significant guard bands around even those. I would never have expected one to bother attempting to detect and identify a narrow band white space device within an operating TV channel.
The only thing that can cause a signal to "increase", as you put it, after modulation and transmission is to have something rectify it and reradiate it. If that's the case, it isn't the TV stations (transmitter) fault, it's the problem with the device rectifying the signal.
But, to state that the radio signals get bounced around and end up occupying more bandwith is stupid, ludicrous and ignorant. Yes, signals get bounced from once item (building (dependant on frequency), ground, mountains, etc) to another, and they change POLARITY, but it has absolutely NOTHING to do with the occupied bandwith.
Your comments have been gratuitously insulting, and this time, irrelevant.
First, I never used the word "increase." I said nothing about power gains. I implied frequency shifts. You are exhibiting some fine book-learning, without taking into account the real operating environment.
You are correct that reflection does not change frequency. However reflection is not the only thing happening to television signals (and any other signal being broadcast on Earth). Earth has this thing called an atmosphere. It is full of water vapor, to greater or lesser extents. Water vapor, and air itself, refracts radio signals just as it does visible light, and refraction does cause frequency shifts. Many other things on Earth are also capable of refracting electromagnetic signals, such as leaves on trees. This refraction does not occur to the entire signal, but it does reduce the power of the signal in its original frequency and spreads that power out across the spectrum into other frequencies. It's what causes analog television ghosting, among other phenomena. My mention of "atmospheric effects" should have been your clue.
For the record, no, I don't work with commercial radio or television. I work with military aircraft, and what I know of radio and spectrum comes from working with military radars. Different frequencies, same principles.
Uh, dude, check your humor detector.
Water vapor, and air itself, refracts radio signals just as it does visible light, and refraction does cause frequency shifts.
Wavelength change != frequency shift.
http://en.wikipedia.org/wiki/Refraction#Explanation:
In optics, refraction occurs when light waves travel from a medium with a given refractive index to a medium with another. At the boundary between the media, the wave's phase velocity is altered, it changes direction, and its wavelength increases or decreases but its frequency remains constant.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Tests rigged? That's not what I get from the director of advanced development for Shure Brothers Microphones, Edgar Reihl.
He was there for the tests last month.
See this article in Broadcast Engineering magazine:
http://broadcastengineering.com/hdtv/reihl-sheds-light-wsd-tests20080819/index.html
And they told him wrong. See my previous posts on this for more details, but wireless mics get slotted into analog TV signals all the time. If that screws up these whitespace devices, what other licensed signals are going to cause problems?
It's astounding what passes for insightful these days. (By "these days" I mean "since the dawn of slashdot")
Wireless mics can slot in between the video and audio carriers of a TV signal and still work (it's pretty fun).
My guess is that the device didn't pick up on this and may have produced transmission intermods. These would essentially show up as new mixed signals that screw with all sorts of stuff.
It's worth noting that "wireless coordinator" is typically a full-time job. The Bears are hiring for one right now. You have to make sure that the mics and monitors don't interfere directly, and then you have to avoid intermodulation between transmitters.
There are software packages to handle this math for you, and the spectrum looks like a Christmas tree when those 40 mics are lit up.
Also note that it's a bitch to reconfigure mics once deployed.
Look at a spectrum analyzer at some point. Those NTSC signals stay pretty tight.
What happens if we approve whitespace devices and then decide to go back to analog, or narrow-band transmission (admittedly unlikely). Then we have these whitespace devices just sitting out there until all of the hold-outs decide to stop using them?
Let badly implemented unregulated devices out in the wild and you stand a very good chance of making a section of the spectrum toxic.
If every whitespace device came bundled with a full-time wireless coordinator, I guess it would be okay.
I'd say you're vastly overestimating the expertise and professionalism of wireless mic users in general. I'm sure *you* do a great job, but these things are sold practically unrestricted to the general public. My high school and college's auditoriums didn't have any RF experts, and neither does my boss's conference room, but that doesn't stop them from using wireless mics. The *average* user of a wireless mic is hardly more likely to be an RF expert than the users of white space devices will be.
main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
Let badly implemented unregulated devices out in the wild and you stand a very good chance of making a section of the spectrum toxic.
One could point out, as another poster already has, that it's already happened. Those self-same wireless microphones that are being so vociferously defended could easily be characterized as badly implemented unregulated devices. Yes, there is a section of the regulations that allows them. It requires manually getting a license to use them, which apparently the vast majority of users never do. They are already proof that unregulated white-space devices can work, without interference with the legitimate license holder of a particular channel, so all of these objections by microphone users are rank hypocrisy.
Now that these devices are out in the wild, they are now making a section of spectrum "toxic" for any other potential whitespace users, first by being dumb analog devices, and second by having a constituency of users that perceive themselves as the rightful incumbents. Guess what. Next to none of them are licensed, so they have NO rights at all to object to being drowned right out.
Except those guys who showed up at the test, like ESPN? Yeah, those guys are licensed. The guys at the Grammys, Emmys, Oscars? Yep.
The likelihood of adoption and dynamic auto-switching behavior make whitespace devices far more likely to cause problems than wireless mics. There's no hypocrisy because there's an FCC regulation section for wireless mics and their usage. Seriously, all these guys have to do is safely scan before transmitting at really low power. I don't think this is an unsolvable problem, but I do think that the cost of allowing a poorly implemented class of devices to be released could be significant and long-lasting.
Sounds like you need to talk with this guy...
So what gear should I have bought? No gear exists that is both able to be operated legally and comes even close to working. You should realize the every single Broadway show is also operating illegally. They can't get licensed either.