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Broadcasting Double Signals
Alan Stovall writes: "The New York Times has a story on broadcasting television (radio etc) signals over the same frequency as satellite services hence doubling the available spectrum. This could have an incredible impact on the broadcast medium." It could, but as the article details, the incumbents are busy quashing it.
http://channel.nytimes.com/2001/04/08/technology/0 8SPEC.html?pagewanted=all
2. Impose some sort of regional limitations, a la DVD. Actually, DirecTV (and other DBS providers) do this already - local stations are blocked based on where they know you to be.
It is important to note that this was imposed on them by local affiliates and the networks. Before that, you got one affiliate on the east coast and one on the west coast for each network. It took a federal judje to turn that simple (and preferable) approach into the hash it is now.
DX'ing TV requires more expensive equipment to find the results as rewarding, but it too is done.
Like a flyback transformer? Amazing how just one transformer acts as the horizontal trace, generates both the high voltage and low voltage power supplies, and syncs the picture. Television electronics is innovative (used to be a good word) when it comes to simplicity.
Building a wireless internet, like building a television should be a good lab project for high school science students.
Whether the technology behind this particular scheme is workable or not, it illustrates the stupidity of auctioning spectrum instead of leasing it. You never know when another, perhaps better use for a particular chunk of spectrum is going to come along, including uses that benefit the public without providing an opportunity for some business to make a profit, so that the government will need to reclaim that particular chunk of bandwidth. If it's leased, it's a lot less of a problem than having to institute condemnation proceedings in an area (unreal estate?) where that concept has never existed before.
I see even classic Slashdot is now pretty much unusable on dial up anymore.
Won't the analog HDTV standrad be obsolesced in a few years by the inevitable digital/internet TV?
cpeterso
The terrestrial broadcast will interefere with the satellite transmissions. I happen to have a large earth station with three 9 meter, a 7 meter, and a half dozen TVRO dishes. We get terrestrial interference all the time from a variety of sources. Northpoint's plan will cause nothing but trouble.
Professional broadcasters go to great lengths to ensure that they are not interfering with the frequencies of others. Coordination of these frequencies is difficult and time consuming.
Intentionally broadcasting on the same frequency is simply idiotic. Northpoint is looking for the easy way to get some spectrum and they are attempting to muscle their way into some free space.
If people want bandwidth they should look at the TV broadcasters. Currently they are each allocated TWO channels due to this insane HDTV fiasco. Settle the HDTV issues and you will have plenty of bandwidth to spare.
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As yet, no one seems to have commented on another Slashdot hotbutton issue here: patenting the obvious. Northpoint claims to have a bunch of relevant patents. The main patent seems to be basically for the "business method" of using directional antennas while hopefully keeping the transmitter power low enough that interference is negligible. If so, that is worse than the "one-click shopping" patents.
Doesn't this work on the assumption that these signals are line-of-sight and don't reflect?
My satellite dish is mounted on the balcony of my apartment and shoots south. However my line of site shoots over a bunch of buildings/trees/etc that could swamp my dish if a signal from the north reflected into my dish. I would assume the terrestrial signals would be much stronger than the satellite signal overhead and could swamp my reception.
Radio is a wonderful hobby. Don't screw up a good thing- anyone with a wire, a coil, and a capacitor can get a signal. Through in an amplifier? You can get signals from around the world. DX'ing TV requires more expensive equipment to find the results as rewarding, but it too is done.
-bugg
The VHF spectrum just doesn't have a lot of bandwidth. If we throw all users off VHF, there's probably a few hundreds of Mbps of data bandwidth. (As a very coarse zeroth-order approximation, max. data-rate is roughly equal to the frequency of the carrier. VHF is 30MHz to 300MHz.)
And carrying TV will require around 1-4 Mbps of bandwidth (depending on the codec) for each video stream. If all the people currently watching broadcast TV switch to watching IP streams... well, let's just say that we won't have that sort of bandwidth for a few years.
Sure there's a lot of tech dreaming and hand-waving about spread-spectrum and all that. Just remember: TANSTAAFL. If you have a certain amount of spectrum available and a certain level of background noise, there is an absolute limit on how many bits you can cram through. Read Shannon's work. (That man was a genius.)
Let's say you settle for MPEG-1 (quarter screen TV). You want to pay for 1 Mbps of upstream bandwidth for each viewer of your TV station? (Widespread multicast is a long way off.)-s
Unlimited growth == Cancer.
It's not a matter of technical limitations.
It's all leagal.
The radio spectrum has been spread apart for various different uses; most often using some frequency ranges to fit a specific task that the frequency is suited for. Unlike most popular opinion, radio waves behave *very* differently at different wavelengths. What might be fine for TV and radio is near useless for networking. Some frequencies are line-of-sight only, while others follow the curve of the earth. Still others bounce off the ionosphere.
Most importantly - anything metallic can receive these radio transmissions. Nearly all of the leagal issues with starting a radio station have to do with being 100% sure that there is no interference with other frequencies/bands. The expertise required to achieve this is *so* far beyond what 'anyone' can do that nobody can start their own little station.
The laws on the books (In the U.S) state that any kind of transmitter has to meet certain criteria. For non-Ham/Ameteur radio operators, this includes that the transmitter must pass FCC certifications for the specific frequencies that the device uses. These devices cannot be modified or serviced in any way; if you want to change frequency, etc, you have to send the thing back to the factory. Home-built gear has to either operate on Ham frequencies, or be at such low power levels that the range is less than a few feet.
And even then, consumer goods can only use a very small wedge of the frequency - and the reasons are more than clear: The consumer radio spectrum is cluttered, unregulated, and very low power.
The high-power, high-range commercial frequencies (and the Ham frequencies) both require FCC licenced operators and equipment. (Although Hams get a huge amount of leeway as long as they use the Ham radio frequencies)
The idea of 'home' internet radio stations using wireless internet is crazy. The amount of regulation is too high, and is all-too necessary to actually have the idea work.
Besides: the broadcast TV/Radio bands are a *really* small part of the radio spectrum. If you want more radio/tv stations, try working on technologies to transmit the informatino in a smaller bandwidth.
Yes... radio bandwidth has to deal with both the frequency of the radio wave, as well as the amount of data it can carry. Want to have 100Mbps wireless ethernet? Fine... but it will take up a huge amount of frequency bandwidth to achieve that kind of data throughput.
People who don't understand just how difficult it is to get wireless technologies to work without interference of others shouldn't be advocating wireless at all.
There are much more Cable channels than broadcast... the reason is because there isn't enough bandwidth to carry the number of channels cable has over the airwaves.
-- Sometimes you have to turn the lights off in order to see.
Why not just forget doing all this and give the TV/Radio bands up for wireless internet? Then the TV and radio stations can use the internet to broadcast thier content. This would enable us to get tv and radio from anywhere in the world and not being confined to our distance from the station or what stations our cable/satalite provider offers. Another benifit of this would be that it would allow anyone to start thier own station with little more than a camera, computer and net access. This could lead to bringing us quality programming (not likely, but it's a nice theory and it's not like it can be worse than what is already on tv and the radio!)
I still long for the day when I can tune into any station in the world from my car over the internet or watch a television broadcast from the other side of the world. Oh and while we're at it, why do we have to see all these stupid on screen displays such as in the case of sports the scores in the corner of the screen. Why I can't I bring that info. up on demand instead of being forced to watch it throughout the entire show?
I'm sure there are some techincal limitations as it stands right now, but if we freed up these bands would wireless broadband be possible? I sure hope so.
.jpg files with hundreds of byte text messages within them. Top Secret documents over the open internet tunnelled within normal connections over the 'net. I'm not sure this is so new or newsworthy as to warrant the title of news.
DanH
Cav Pilot's Reference Page
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Is this really anything new? Women have been doing it for years.
Actually, that's pretty simple. The color signal took no more bandwidth and was 100% compatible with the old B&W receivers. Broadcasters needed no extra bandwidth to add a signal which would not drive away their old customers, but which would attract the new customers who sprung for color TV sets.
By contrast, HDTV requires a totally new infrastructure of camera, recording, editing, and broadcasting equipment which is not compatible with the 300,000,000 or so existing TV sets. Bear in mind that amplifiers and editing equipment built for B&W will generally work with color, but nothing built for standard TV will work with HDTV. And HDTV only works for standard signals if it is essentially "dual mode," much more of a leap than the added expense of designing color circuitry into what was originally a B&W design.
There is also a much larger infrastructure of this more incompatible equipment than there was during the adoption of color. Someone has to toss out the first dollar and so far neither the producers, broadcasters, nor public have been willing to take the risk that they will be caught holding the next generation's version of a Beta VCR.
Brackets contain world's first nanosig, highly magnified:[.]
Whats the purpose of selling something if there's likely to be issues somewhere down the line via way of quality. I understand its a nice idea, shit I would like to see it take flight just because its a new concept, but arguably, its no better than digital satellite reception, the clarity, etc., its only saving you a few bucks... Wait I take that back, since its local programming, its not like your paying for it anyway, so this wouldn't neccessarily affect the avg person, unless their paying to watch local tv via sattelites without getting cable access.
U.S. versus Japan (secret showdown)
360 degrees of Karma
If the licenses at issue are put up for competitive bids, Northpoint executives say they will walk away from the market, taking with them the patents that they say protect the only known technology for offering a new alternative to subscription television.
So these guys want the gov't to give them the frequencies (for the greater good of mankind, of course), and if that doesn't come to pass, Northpoint'll just take its ball and go home. I'm curious what exactly in these patents is so valuable (and who do they 'protect' the technology from, exactly?)
"Mr. Tawil observed that a porch light behind him did not obscure the twinkling stars overhead." - Isn't this is what light polution is about, the reason I can barely see the stars from where I live. And my friend living out in the country has a wounderful view of the night sky? Any way they'll probably prove in a few years time satalite tv gives us cancer... doh!
~www.devnull.co.uk