(Short-, Medium-, Long)wave Radio Meets Digital Stereo 194
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.
DRM? (Score:5, Funny)
Re:DRM? (Score:1, Redundant)
Why not WMD for Wireless Music Device? (Score:5, Funny)
Or PMS for Portable Media System?
Or any of a thousand other shit-poor choices for acronyms?
Re:DRM? (Score:5, Funny)
Wie sind die Borg... (Score:3, Funny)
Come on, we've heard enough about DRM from M$, now from German DJs?!?
Re:Wie sind die Borg... (Score:4, Funny)
Yeah, how are the Borg?
(Wie = How, Wir = We)
Re:Obligatory simpsons reference (Score:2)
I don't care about Karma.
Is there any point to this? (Score:1)
Sure... (Score:2)
See, they said stereo, and eveyone knows these SW wonks have loads more than just one crystal set laying around...soooo. They'll just wind one up for use w/the LEFT channel, and then dial in another Radio Shack Gold Klondike SkyMaster SW68-006 Horizon Buster II for the RIGHT channel, and won't we be the stupid ones
Yes, Earl??? Dorothy, I gotta call the guys over at NASA...there's something going on up there. Wh
Nice! (Score:5, Interesting)
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?
Re:Nice! (Score:5, Funny)
Sure. You see, it's far cheaper to use as-yet-experimental state-of-the-art technology than to continue using transmitters and technologies that have been in use for decades and that are well understood and easily serviced by thousands of technicians.
The new transmitters will no doubt be fitted in, say, a few weeks. Then, in about three months, just about every household in North America will have bought the new receivers, and switch to tuning in small transistor radio sets to BBC broadcasts, instead of, say, surfing pornography or using AOL. Once the BBC starts digital broadcasts, well, no one will want, or need, broadband internet connections!
Notice that the bitrates used in these AAC streams are wayyyy too high to ever be transferred over a dial-up connection. Even IF PCs could be equipped with AAC decoders, or similar codecs, such as ogg vorbis, the bitrates needed, some even exceeding 22 kilobits per second would prove a lethal hurdle for people who would want to listen to a stream using such a "magical" codec on their PCs..
Plus, other, existing, methods of delivery for digital radio, such as satellite, are clearly inferior to this new technology.
</SARCASM>
cynicism is cheap. (Score:4, Insightful)
Re:cynicism is cheap. (Score:3, Informative)
With regard to your comments about satellite being expensive - already companies are selling satellite tuners that connec
You will need special gear (Score:5, Informative)
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....)
Re:You will need special gear (Score:5, Insightful)
-KC0NBY
Re:You will need special gear (Score:5, Informative)
Did you ask your friend to put the PSK31 signal on the speaker? The really cool thing about PSK31 is that your computer can copy a signal you can't even hear.
(For anyone who's wondering, we're still talking about digital radio. PSK31 is a modulation technique for text which fits a slow TTY-like signal into 31.5 Hz of bandwidth).
Re:You will need special gear (Score:3, Funny)
Umm yeah that's cool that I can't hear radio waves, I think.
Re:You will need special gear (Score:2)
Last I checked, 'radio frequency' doesn't come out of a speaker. Radio waves are a form of light? Gee, well then by that analogy, sound waves are a form of light too, arn't they?
From the grandparent:
Did you ask your friend to put the PSK31 signal on the speaker? The really cool thing about PSK31 is that your computer can copy a signal you can't even hear.
On the speaker. The speaker does not transmit 'ra
Re:You will need special gear (Score:2)
Dumbass. That wasn't an analogy. Light as we see it is simply specific frequencies of electromagnetic radiation. Radio waves are also just EM radiation at specific frequencies. Therefore, depending on how you look at it, radio waves are just a form of light... they just happen to be at a frequency too low for the human eye to perceive (much like infrared).
Contrast this with sound waves. Sound waves are physical waves trave
Re:You will need special gear (Score:2, Informative)
Most likely you guys weren't using more than a few hundred watts, or an antenna more than 100 feet off the ground.
But not everyone can be allowed to run a megawatt generating gas turbine to power the radio rig in their back yard, otherwise braces, metal rimmed glasses, and umbrellas would become unpopular very fast.
Broadcasters always have the edge over certin technical problems becase they can pump out megawatts, have 1-2 thousand feet towe
Re:You will need special gear (Score:2)
My understanding of these matters is limited, but the description on their website makes it sound like they are using a sort of spread-spectrum scheme.
They claim signal quality equal to FM... but I suppose that depends on how much data redundancy they have across their frequency range. They claim to be able to reconstruct missing or corrupted sections of data... is there some error checking built into this as well?
Re:You will need special gear (Score:5, Informative)
It's similar in purpose to CDMA. It is spread spectrum, sorta. It uses many narrowband carriers transmitting in parallel. The data transmitted on the subcarriers uses forward error correction coding, it's sorta like RAID1 for radio. They can also use tricks like sending the more important data at lower speeds. It's a pretty robust system, but it was mostly designed to combat multipath fade at VHF and above.
To answer my own question (Score:5, Informative)
Wrap your brain around this. [digitalradiotech.co.uk]
I tried to digest all of it...
Now my head hurts.
Re:You will need special gear (Score:3, Informative)
Not so special (Score:5, Interesting)
Re:Not so special (Score:3, Interesting)
You'd need to bring that down with another mixer to below about 20 kHz so that the filters on the soundcard won't trash it, or you would have to bypass the filters on your soundcard and subsample it.
Re:Not so special (Score:3, Interesting)
Re:Not so special (Score:3, Interesting)
These outputs are past the demodulater, so you get a unfiltered basenband signal.
You need a IF signal as that still has the properties of the RF signal. Most smallband FM rigs or AM rigs have a second IF of 455 or 473 Khz which can be mixed down to 12Khz rather easily. This can then be sampled with an audio card.
Jeroen
Software defined radio! (Score:4, Interesting)
It's already been used to decode HDTV signals [slashdot.org].
Slashdot also covered [slashdot.org] this technology a couple years ago.
Re:Software defined radio! (Score:3, Interesting)
Also, I do Software Defined Radio [p25.com] for a living.
However, the point of my previous message is that the average person with the average receiver is not going to be able to receive this signal.
Re:You will need special gear (Score:4, Informative)
Re:You will need special gear... DL the standard (Score:2, Informative)
If you really want the spec visit the European Telecommunications Standards Institute (ETSI) website [etsi.org], search [etsi.org] for Digital Radio Mondiale, register for free and download the system specification.
The first? (Score:4, Funny)
Hardly the first. Lisp has been doing this for decades.
-- ShadyG
Re:The first? (Score:3, Funny)
Re:The first? (Score:1, Informative)
ham radio (Score:2, Interesting)
Re:ham radio (Score:4, Interesting)
"The RF bandwidth can be chosen between 4.5,5, 9, 10, 18 and 20 kHz", according to an article at drm.org. Ham voice transmissions already fit inside 3KHz.
There's also a bucket of features which are great for broadcast, like redirect pointers to better frequencies, which are irrelevant bloat in the ham world.
Re:ham radio (Score:2)
One of the oldest digital HF modes was FSK RTTY (radio teletype), which you could send text at 45 baud. It lead to AMTOR text at 100 baud. Then came PACTOR at 200 baud, still very popular, with built-in ARQ and compression. PACTOR begot PACTOR II and III, GTOR, CLOVER, PSK HF modes.
PSK31 is popular now, but is intended for human-to-human highly reliable communication at 31 baud.
You will notice that the Amateur digital modes are all extremely narrowb
BURN THEM! (Score:4, Funny)
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!
Text of website... (Score:4, Informative)
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.
yet another avenue for Peer to Peer (Score:5, Interesting)
Re:yet another avenue for Peer to Peer (Score:3, Informative)
Its one thing to stream digital data and have it picked up by a device and spat out via a DAC.
Its another thing altogether to have to co-ordinate lossless data transmission. You are going to need a protocol that handles retransmission CRCs etc... i.e. some sort of transmission control protocol maybe?
People have been getting all sorts of stuff. Digital stuff over SW for a long time now, bouncing packets of meteor trails containing e-mail and shit.
Good idea... bit l
Re:and with signals this weak.. (Score:2)
Re:yet another avenue for Peer to Peer (Score:2)
Broadcasting over shortwave is not peer to peer, it's one-way! It costs a lot of money and requires a lot of permits to build a shortwave station strong enough to actually send data long distances.
Re:yet another avenue for Peer to Peer (Score:3, Informative)
I suppose if you had a reciever and a transmitter, with a lot of bands open, and can "hunt" bands, it might work but those are big ifs. You'll be able to transfer data, but my guess is that bandwidth and latency are still big issues, but still secondar
Redundancy for satellites... (Score:4, Informative)
Maybe a LOT of old, low-fi, unreliable radio broadcast technologies can have useful new digital life. It could be very handy as a backup for satellite-based communications.
Re:Redundancy for satellites... (Score:3, Interesting)
Maybe it was on slashdot? was a year or two ago now tho'
HOBO XM? (Score:1)
Re:HOBO XM? (Score:2)
Isn't going to fly (Score:4, Interesting)
'Ya know, I used to think short wave radio was cool - until I discovered internet broadcast. Now I can listen to stations around the world, without buying any extra gear.
Maybe in the 3rd world, oh wait, the gear is going to be more expensive than SW radio - maybe not there either. Who is going to buy this to get the mass market price down? Not me.
Re:Isn't going to fly (Score:2)
Me, me, me, me! One of the reasons that internet broadcasting sucks, is that I have to use a lot of bandwidth for an FM quality stream... If someone wants to listen to something else, more bandwidth.
Also, good luck taking your intrnet streams on the road. Sure, you CAN do it, but you probably need to listen to lower quality broadcasts, and are probably paying through the teeth for the data connection.
Meanwhile, a small investment in some good equipment, and you can listen to th
I always thought (Score:2)
DRM was a 4 letter word around Slashdot.
Re:I always thought (Score:2)
It's a 3-letter acronym.
Citizen's bandits (Score:5, Interesting)
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.
Re:Citizen's bandits (Score:2)
I think you want something far more advanced than a soundcard. You would want something with DSS, and all sorts of other flow control, unless you just want to broadcast something small and simple a short distance.
You are right though, I've been using a CB for as long as I can remember. 10+mile communications for tiny (handheld or vehical) units isn't unsusal, and the big units go much much further than tha
Re:Citizen's bandits (Score:2)
Re:Citizen's bandits (Score:2)
This ain't packet radio.
Re:Citizen's bandits (Score:2)
Then explain how it's different to someone who thought packet radio was really cool, got a TNC, played with it for a few months and decided that they were wrong...packet radio was not cool, it in fact both sucked and blew at the same time. What could be done different at 11 meters that HF and VHF packet radio is not currently doing, short of being 802.11ish/long haul building to building wirelessish?
Re:Citizen's bandits (Score:3, Informative)
Modems use ~3khz of bandwidth to get >48kbps. HF channels have more than twice that bandwidth available, and if you are using a digital front end there's no reason at all you can't use more than channel at the very same time. Use two VHF channels (say, on the also-unregulated 49mhz band) and it's not at all unreasonable to expect >200
Re:Citizen's bandits (Score:2)
Now how do we make that happen?
Re:Citizen's bandits (Score:2)
You start a company to build it, or seriously encourage a current communications company to use CB bands.
I like it! (Score:3, Interesting)
Bit-torrent is a pretty cool and hip standard in it self, but imagine releases sent digitaly via the airwaves, using a simple 50ft long wire that can reach between seattle and finland. Not perfect mind you, even the best sets are going to have some unrecoverable packet loss, but hey. Not exactly ideal for let's say a linux distro, but through the use of checksums I can see how such a broadcast service could get you most of what you need, and anything that fails you can just download via standard means.
And as a bonus... to people who have a broadcast license, could open the door to ham based ISPs. While a dated technology, short wave / long wave is a proven one. While i'm sure statalight would no doubt be superior, land based access would be cheeper to deploy, and can even be based on older tube technology.
This is something i'd use, even if just to get music from overseas.
Except.. (Score:2)
So opening up a "HAM based ISP" is probably not legal in most places.
Re:Except.. (Score:2)
Right (Score:2)
Deutche Welle needs a name change. (Score:2, Funny)
Re:Deutche Welle needs a name change. (Score:3, Funny)
Just like you can't use the word "niggardly" anymore because it looks like it should be offensive.
Re:Deutche Welle needs a name change. (Score:2)
Of course it's pronounced "Bump-us". I was thru there a couple of weekends ago.
Are you serious? (Score:2)
It sounds like, well, like shortwave.
Acronyms (Score:2, Interesting)
1. Digital Restrictions Management (M$)
2. Direct Rendering M(anagement?) (XFree)
More useful than music broadcasting? (Score:2)
Wonderful. But...... (Score:2)
Part of what makes AM Medium or Shortwave so important is the ability to receive it with inexpensive receivers. If there is something you want or need to listen to there and you live in some third world country, chances are you're not going to be able to afford some nice new digital receiver.
And remember that the third world is usually the target audience for this stuff. It's used to get religious or political programming to those who wouldn't otherwise h
Re:Wonderful. But...... (Score:3, Insightful)
Dude.... how much is a cellphone now? Aren't they giving them away in blister packs at the grocers?
It's just another digitial radio. The only thing hindering this is a standard; if there were a WARC approved standard and a few broadcasters using it there would be twenty dollar receivers being sold at ratshack - and handed out i
Re:Wonderful. But...... (Score:2)
How much is a mini-satellite dish? Obviously, it's super cheap, if not free, because the service charge is where they make up their money. No suck luck with shortwave radios, although, I admit it shouldn't be very expensive ($50) in a year or so if they mass produce them.
Re:Wonderful. But...... (Score:4, Insightful)
In third world countries?!?!? The last time I was in one of those places they wern't giving anything away. Hell you couldn't even get a decent selection of sanitary food in some of those places.
It's true that cell phones cost far less than they used to due to the scale of mass production. Still most retail for $150 US on up. The ones being "given away" are usually refurbs as those have no other market value and it's a cheap way for the carrier to get you to spend an airtime dollar if you're too cheap to sign a contract and buy a phone.
The difference as I see it is that this radio market is going to be a tiny fraction of what the cellular communications market is. So I doubt there will be the kind of numbers you need to bring receiver price down that far that fast.
Maybe the MW market will help drive the price down somewhat and make it afordable for the SWL market. But MW is a hurting market too. If you're in the US you might remember how the MW broadcasters tried like hell to save their market share with the miracle of AM stereo. Or maybe you don't remember that...which would make my point. A lot of people just don't bother with that band because they can get all the programming they want on the VHF FM band without propagation flutter and fade.
Seems to me that the MW and SW listeners are a different breed with different requirements. They're not after high quality signal, they're just happy to have signal. They're not after full digital stereo news, they're just happy to hear the news at all.
Besides, Rush Limbaugh gets his point across in analog mono just the same as he would in digital stereo.
Re:Wonderful. But...... (Score:2)
In the US most cellphone proviers will give you
Re:Wonderful. But...... (Score:2)
Metric, PAL, GSM,
Neat... any open source implementations? (Score:2)
I was at the 2003 NAB and heard AM IBOC digital (Score:5, Informative)
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!
The magic words... (Score:2, Informative)
Well thank God it's not based on WM9. Unfortunately some DAB radio solution manufactures are looking into WM9 instead of MP1 layer II. I can only conclude they are mad and want their company (and the world) to be ruined like Sendo.
DRM Sales pitch (Score:3, Informative)
DRM is going to be certified by ITU (International Telecomms Union), basicaly the body that gives the certs for these kind of things.
Most of the digital radio concepts failed because they were able to produce a small run of say 10,000 receivers that would cost an arm&leg when they hit the streets. Well, it seems that DRM will not share this fate, since China, having poor radio coverage in rural areas (FM not viable, shitty AM/SW reception) has chosen DRM as their new standard. Starting run will be ~14mil receivers, so from start they will be able to produce them dirt cheap. Basically the deal is that the West will supply the transmitters, and China will flood the market with cheap receivers.
Otherwise the test rig shown at the pitch sounded really good.
This is what we need in the US (Score:2)
Screw IBOC. AM/FM need a digital makeover, not a legacy-supporting and shitty sounding downgrade.
Re:but then ... (Score:5, Insightful)
Re:but then ... (Score:3, Informative)
Re:but then ... (Score:2, Interesting)
Re:but then ... (Score:4, Informative)
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?
Shortwave News provides a different perspective (Score:2, Insightful)
I listen to SW news to get a different perspective of the world. The local and network news in the US is politically slanted and full of sound bites. Where I live, the BBC, Radio Netherlands and Radio Cuba have strong signals at night.
I was listening to the BBC when it was first announced that Lady Di died in a car crash. It was a solemn moment The Brits did it with dignity. The American press handled it like the tabloids.
Re:but then ... (Score:2)
*please pay no attention to italics
*Note sarcam may disrupt some computers*
Re:but then ... (Score:5, Informative)
"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.
Re:but then ... (Score:2, Informative)
Re:but then ... (Score:2, Insightful)
Obviously, the person who commented thus had either a) never listened to the sample clips or b) never heard an FM radio that cost more than $5.
Re:but then ... (Score:2)
Or he can't find anything but top 40, country or hip hop in his area. With signal quality that low, I'd hate to see other bands striving for that qualiry.
Time for a Slashdot Definition (Score:2)
DRM = Digital Restrictions Management.
No rights are being given... your fair use is being taken away. Pay attention. If you argue, I guess your entire collection will be stored in non-transferablae WMA's. Or will you "buy" the right to listen to them each time you want to hear them. Somebody rank all these, including this one off-topic...
DRM, what a terrible acronym
Re:Time for a Slashdot Definition (Score:2)
Hardly. All of the music on my music server is on hard drives contained within a Macintosh. iTunes allows you to purchase songs encoded in AAC with no DRM associated with them. Pretty nice. Give it a try.
Re:Okay... (Score:5, Informative)
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.
Re:Okay... (Score:2)
Re:Okay... (Score:2)
Re:XM (Score:2)
Re:Aww... (Score:3, Interesting)
Interleaving (Score:2)