Digital Radio Mondiale, a Better Standard Than US-Adopted IBOC? 134
Gsparky2004 writes "Over at Engineering Radio, Paul suggests that Digital Radio Mondiale (or 'Digital Radio Worldwide') may be a better alternative than the US-adopted, proprietary IBOC system. But he's concerned that the FCC is too far down the 'IBOC is the way!' road and won't accept an open source alternative, even one that may work better." For a slightly more pointed take on the matter, check out this anti-IBOC site, which paints IBOC as something akin to the devil himself.
Re:Wow! Amplitude Modulation! (Score:3, Informative)
Different, not necessarily better. (Score:1, Informative)
The single biggest complaint from the anti-IBOC crowd, interference with existing analog stations in hybrid mode (coexistent analog+digital), is not somehow avoided by DRM. In fact, the author simply suggests skipping hybrid mode altogether and jumping wholesale into DRM. Given the massive installed base of broadcast and reception equipment, it is naive to suggest that analog could be abandoned overnight in favor of a new digital standard. The alternative is to use hybrid DRM mode and face the exact same problems as hybrid mode IBOC.
Digital Radio Mondiale is not entirely free (Score:1, Informative)
Digital Radio Mondiale may be non-proprietary, but it relies on patented technology. These boys [vialicensing.com] will sell you a license.
Re:Does anyone care either way? (Score:3, Informative)
DRM+ is a vastly better standard than DAB. DAB should have never existed. If you want to replace traditional FM local stations, DRM+ is an excellent choice -- better coverage and higher quality with less power and using less spectrum. If you want to cover a huge area with a MUX, DVB-T2 is what you want and it can transmit a large amount of channels in one MUX. DRM+ is one channel per MUX, but that isn't a large problem since there is room for many MUXes in just a small amount of spectrum.
Re:Does anyone care either way? (Score:5, Informative)
The big problem that DAB suffers from is battery life - an FM radio can last far longer than a DAB radio on the same set of batteries. Do you have any figures for power usage for DRM+ decoders compared to FM radio? If it's just driving headphones, a pocket FM radio can go for quite a few days on single AA radio. DAB seems to use about ten times as much power.
For in-car use, power isn't such a problem, although hand-off between towers is. For in-home use, you're likely to have Internet Radio as an option, with a lot more channels (I'm in the UK, and I'm currently listening to a station in California...).
Re:Wow! Amplitude Modulation! (Score:2, Informative)
"I'd suggest hooking up an AM modulator to the line out of a music device, and they'll get their mushy distorted sound the way they like it."
That is exactly what I do to show off my antique radio collection. Too bad you are so young that you have never heard a high-quality AM radio. They are neither mushy, nor distorted. Most AM radios made between 1953 and 1973 are of very high quality and high fidelity, capable of audio frequency response in excess of 15 KHz. AM radio sounded VERY good back in the day before the "loudness wars" started. There was also no, or very little, interference plaguing the band back then. Many of the devices you consider to be "improvements" in technology have been a factor in destroying the AM band due to the interference they create. ...now get off my lawn!
Re:Does anyone care either way? (Score:4, Informative)
Here's what the "open" system is using... (Score:3, Informative)
According to TFA [engineeringradio.us], the (more) open system is actually relying on a number of not-so-open protocols and formats.
* Open source system. Royalties are paid by the transmitter manufactures only (and do date, most major US transmitter manufactures have already paid these). There is no royalties paid by the broadcaster to install DRM or by the consumer when purchasing a DRM capable receiver. One company does not own the rights to the modulation system for all the broadcasters in the country.
It's good that no royalties have to be paid by broadcasters or consumers, but given that I was just at the Open Hardware Summit [openhardwaresummit.org] and have a curiosity about things like GNU Radio [gnuradio.org], hopefully the amateurs won't be shaken down if they build their own receivers or transmitters.
* The CODEC is HE-AAC 4, which is widely used world wide.
AAC is patented [wikipedia.org], and they make you pay money.
In addition to that, DRM30 station have the ability to transmit low frame rate H. 264 video.
H.264 is patented [wikipedia.org], and they make you pay money.
The thing is, even if this isn't a completely open format, it's entirely plausible that this is the closest that anyone has gotten. While we could consider using this for now, we should always look forward and try to figure out how open we want the next set of standards to be.
Re:Wow! Amplitude Modulation! (Score:3, Informative)
Try the internet. I listen to AM Liberal Talk radio from Chicago. http://www.streamingradioguide.com/ [streamingradioguide.com] and a search for Rachel Maddow is how I originally discovered it.
IBOC/HD Radio vs. DRM - there's no real difference
(1) Both broadcast analog-and-digital side by side
(2) Both are designed to transition to 100% digital broadcast at ~60 kbps on AM and ~250 kbps on FM.
(3) Both cause interference with long distance stations ~100 miles away. Oh well.
(4) Both will eliminate that problem when moved to 100% digital.
.
IBOC/ HD Radio has one advantage that Digital Radio Mondiale (DRM) does not have : Multiple programs. IBOC/HDR can broadcast 7 programs on a single station. For example my local station has Top40 hits on HD1, Dance music on HD2, 80s/90s on HD3, and a low quality traffic/weather channel on HD4. The DRM standard does not offer the same feature.
Re:Why does this still exist? (Score:3, Informative)
No, antenna size is not a function of distance you want to cover. It's a function of wavelength, at 2.4GHz it's 12.5cm, and at 1000kHz, smack in the middle of the US AM band, it's 300m.