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(Short-, Medium-, Long)wave Radio Meets Digital Stereo
cryptec writes "Today shortwave radio will have some new life pumped into it as the German broadcaster Deutsche Welle will be the first full time shortwave broadcaster of DRM (Digital Radio Mondiale). DRM is a full stereo fully digital broadcast system. The quality of the broadcasts are close to that of FM radio. For samples check out this link." Akai adds this link to an article in the San Francisco Chronicle with some more information, like the involvement of the BBC and Voice of America in this undertaking.
I don't think that's a popular acronym around here.
The goatse guy for president. Win one for the gaper!
Digital radio over SW sounds interesting. I wonder if old Auntie's going to pick this one up? I gather BBC services got cut over North America recently in favour of web broadcasts... maybe digital technology will allow that to be reinstated in the future?
Real Daleks don't climb stairs - they level the building.
Obviously, you will need special gear to receive this - they are using COFDM so your normal shortwave rig is unlikely to give you anything meaningful.
I suppose IF you had a single-sideband rig with a wide enough filter set, and IF you then used your computer, you COULD decode this, but the usual means is going to be a dedicated receiver.
(Hmmm. Have to see if I can get the spec, and see if I can write a decoder for it....)
www.eFax.com are spammers
Hardly the first. Lisp has been doing this for decades.
-- ShadyG
Nerd Rock In Progress
Deutsche Welle will be the first full time shortwave broadcaster of DRM
Broadcasting DRM! How dare they! First, they try to stuff copy-protected CDs down our throats. Then they introduced copy-protected HARDWARE! And now, they're trying to RESTRICT OUR RADIO!
WE MUST BURN TH-eh? Read the article? Bah! I'm fighting Digital Rights Management! No time for that!
RANGE man, range! worldwide FM quality shortwave is gonna be cool.
My potato gun was confiscated by the United Nations. They said I wasn't allowed to have weapons of mash destruction.
Or IRS for International Radio Service?
Or PMS for Portable Media System?
Or any of a thousand other shit-poor choices for acronyms?
Is this truly the only Earth I can live on?
The British Broadcasting Corp., Voice of America and other international broadcasters launched digital short-wave radio service Monday, promising to provide near-FM quality in the place of static-filled signals.
Digital broadcasts don't increase a station's range, but they eliminate static and let broadcasters transmit text, such as news updates and song information, with the audio signal. For now, digital radio receivers are considerably more expensive than analog radios.
The Digital Radio Mondiale consortium launched its digital service at a global radio meeting in Geneva.
"DRM's introduction will forever alter the course of radio broadcasting," said Peter F. Senger, chairman of the consortium, which has more than 80 members.
The initial signals were transmitted from a nearby mountain in France shortly after 8 p.m., when Senger gave the word during a ceremony in conjunction with the World Radiocommunication Conference in Geneva. The conference is held every few years to decide airwave issues such as the sharing of radio and satellite frequencies.
Simultaneously, other short-wave broadcasters started using digital transmitters in different parts of the world. The transmissions received at the reception featured voices in Chinese, French, English, German, Russian and Spanish, followed by static-free music.
For the foreseeable future, broadcasters will use both traditional analog systems alongside the digital transmissions so people with traditional radios will still be able to tune in. At first, broadcasts will be aimed at Europe, North America, the Middle East, Australia and New Zealand.
Digital radio signals are duplicated enough so that even if some are lost from interference, the receiver is able to put the transmission back together so it can be heard correctly. And Senger said the system uses much less electricity than analog, which will save broadcasters considerably on their biggest cost item.
Although the Federal Communications Commission has approved a different digital standard for U.S. domestic broadcasters, Senger said the new system is meant to be universal and could eventually be used in the United States.
Other broadcasters in Europe, Asia and Canada have been using digital transmissions for several years. That system, known as Eureka 147 or DAB, uses a different set of frequencies than traditional AM, FM or short-wave bands.
My potato gun was confiscated by the United Nations. They said I wasn't allowed to have weapons of mash destruction.
Say what you want to about the utility of digital music over short-wave, I think it's a fascinating development. It's just another big application of Peer to Peer technology, one completely bypasses the internet. It's not just music that can be broadcasted this way - files can be sent and they could contain anything - newspapers, video, software, worms - and they could come from anyone with enough power to broadcast them. If the use of such technology becomes widespread enough - look for this becoming just another way to suck data into your computer, no matter how isolated you happen to be.
The flag just makes more sense than the constitution. - Judas Gutenberg
"what's the point ? maybe I missed something ?"
Well, here in the UK, there's a point. Already the BBC has squeezed so much into it's limited DAB multiplex, that it can only pump out BBC Radio 7 at 80kbps MONO. It's World Service, which sometimes broadcasts music, has an output of 64Kbps MONO, as does it's Asian Network.
If it shifts these services to (ugh) DRM, then the they can be output in stereo, probably at better rates. The remaining services can go up in quality (BBC 6 Music, currently at 128Kbps on DAB, could go up to 160, etc.)
More bandwidth, at better quality. I would guess that that's the point.
Corporation, n. An ingenious device for obtaining individual profit without individual responsibility. - Ambrose Bierce
There are in the US people who actually live so far out in the middle of nowhere that shortwave is the only option for radio unless they want to put up a huge antenna.
Its also a fairly widespread hobby. Starting cost can be as low as $10 for a garage sale world band radio up to several thousand for the latest in equipment.
Its pretty fun being able to hear programs from austalia, india, or wherever someone can muster a few kilowatts to bounce a signal off the ionosphere.
A receiver with a wideband IF output (ie just about any ham receiver), a PC, and a soundcard. That ain't so special; some of you need to free your minds, much less free your radios.
here's a website I found in the UK that gives a very detailed explanation.
Wrap your brain around this.
I tried to digest all of it...
Now my head hurts.
Even if a man chops off your hand with a sword, you still have two nice, sharp bones to stick in his eyes.
In an area where 802. gear is pretty much useless because of line of sight issues, this might be just the ticket. There is more bandwidth in an HF carrier than in a phone line, and using low cost DSP tx/rx front ends it would even be possible to utilize two or three channels at once.
Hmmmm.... I think I need to go visit the neighbor.
>> Does anyone still listen to shortwave?
Yes.
SW is the only communication you can get in certain poor rural zones, because:
- telephone lines are too expensive to install;
- same for optic fiber & microwave links;
- FM&AM&TV are't close enough;
- satellite receiving equipment too expensive;
- internet requires one of the above;
- etc.
People really use SW, because they need general news, government announcements and entertainment.
Of course, this idea will only work if someone can come up with an inexpensive enough apparatus.
Now that I come to think of it, this is like Vorbis streaming thru internet, over amateur radio.
Hey, Cringely, do you want cheap internet access? (ok, your project was way cooler, but then, not that cheap...)
One could use a range of frequencies to get more bandwidth (duh). Is this spread-spectrum?
In the Harris booth they weren't even running it in stereo. They were using mono voice and it sounded just awful - full of really bad artifacts that made the speaker sound like he was gargling liquid while speaking.
A German fellow came up and was listening to the audio on a second headphone. he commented at how awful it sounded. Turns out that he does DSP for a living - perceptual coding in particular. he had done some work on the coser used and was embarrassed at what he was hearing on the headphone.
By contrast, the DRM samples I hear here sound just great! ...and this with dual (dueling?) bit rate conversions (analog > DRM > MP3 > analog).
FM DAB sounds somewhat better...but then again is's using a 96K bit rate - even Windows Media sounds good at that high a bit rate!
What I'd like to hear is OGG at both the 32k bit rates of AM DAB and the 96k bit rates of FM DAB... My guess is that it would sound great!