Talk:Digital Radio Mondiale

Criticism

Should add a section. From the reading I've done, the DRM signal becomes totally unreadable at a time when a comparably distorted analog signal is still audible and listenable. It appears to be an unreliable format compared with analog. Also, as SW is still primarily used to disseminate information in the third world, DRM will not be used in areas where the cost of the technology is too high. A $250 radio for every family in Africa and India? I think not. Broadcasters will continue transmitting in analog, so they can be picked up by the millions of listeners with $5 analog radios.

DRM sounds like a much better idea for medium-wave AM, which broadcasts locally and won't suffer the signal degradation, but for international SW broadcasts it's so unreliable as to be useless.71.205.209.100 21:19, 21 August 2007 (UTC)

Misuse of the term AM. AM is an American term for medium wave, which by definition is not shortwave. — Preceding unsigned comment added by Hnolson (talk • contribs) 21:12, 21 October 2011 (UTC)

Ofcom and UK adoption

I haven't found a referencable link as yet, but I got it in a work newsletter. Ofcom is seriously considering not renewing Virgin and TalkSports' AM licenses so that they can reuse the AM bandwidth for DRM. - David Gerard 09:24, 27 September 2006 (UTC)

Low bitrate

The given bitrates of "8 kbit/s to 20 kbit/s" seem extraordinarily low compared with the ~128kbits/s typical minimum for reasonable AAC. Can someone explain this in the article? Is there a byte/bit error? Hotlorp 13:03, 7 December 2006 (UTC)

Actually it's AAC+ (or HE-AAC) which sounds good at only half the bitrate of MP3. I routinely listen to a 24 kbit/sec AAC+ station via internet streaming, and it sounds just as good as FM (i.e. nowhere near CD quality, but still a lot better than AM). Plus if you read the wiki article on this subject it states, "Further controlled testing by 3GPP during their revision 6 specification process indicates that HE-AAC and its derivative MPEG-4 HE-AAC v2 provide "Good" audio quality for music at low bit rates (e.g. 24 kb/s)."

Also the bitrate is comparable to what AM-HD Radio does with 10 kilohertz space (20 kbps), so I don't think there's an error there. Let's face it; you can't squeeze a lot of data into only 10 kilohertz. It's somewhat similar to trying to squeeze data through an 8 kilohertz-wide phone line. Recall that dialup is limited to ~50 kbps, and only if the line is perfectly clean. - Theaveng 22:16, 25 September 2007 (UTC)

Removal of comparison with HD-Radio

I had several reasons why I removed the following statement:

For comparison, pure digital HD Radio can broadcast 40 kbit/s using 10 kHz width and 60 kbit/s using extended bandwidth.

• It compared audio bit rates for DRM with link bit rates for HD-Radio
• HD-Radio uses channels 20kHz wide in all-digital mode for rates ~40 or ~60kbit/s (depending on robustness) and 30kHz wide channels in hybrid (analog+digital) mode for rates ~37 or ~57kbit/s (again depending on robustness). See The Structure and Generation of Robust Waveforms for AM In-Band On-Channel Digital Broadcasting [PDF, pp.6-8, 242KB].
• Link rates for DRM on the other hand are provided only for channels 9kHz (max.~31kbit/s) and 10kHz (max 27.4kbit/s) wide
• Unfortunately the same misinformation is provided on HD-Radio page in section AM-HD vs. AM-DRM as well

24.81.130.107 09:14, 28 September 2007 (UTC)

I reviewed the white papers, and it turns out you were at least partly correct. Thanks for point it out. HD-Radio does fit into a 10 kilohertz channel, but that mode is limited to only 20 kbit/s. I've made the fix in the article. (Why was it necessary to delete the whole sentence????) (All you need to do was fix the mistake, not delete everything.)

As for DRM, I don't see any citations to support your "27.4 kbps assertion. Can you please provide some? Thank you. - Theaveng 10:09, 28 September 2007 (UTC)

You are right. It's not 27.4kbps. It's 34.8kbps :-) [PDF, 4.5MB, pp.19]. I should probably also mention that the maximum achievable speed is 72kbps for mode A, bandwidth 20kHz and lowest robustness level. 24.81.130.107 12:27, 28 September 2007 (UTC)

Ya know, I just scanned that whole PDF document, and I see nothing to support your assertion. Please provide specific page numbers or Table/Figure numbers. Thank you. - Theaveng 13:59, 28 September 2007 (UTC) ---------- UPDATE - Never mind; in the article you told everyone it was on page 19. So let's see if I understand how this system would work for a U.S. application (10 kilohertz) using kbits/second and 64-QAM:

• 5 khz == 16 (day), 13 (night), 8 (maximum robustness)
• 10 kHz == 34 (day), 27 (night), 17 (maximum robustness)
• 20 kHz == 72 (day), 56 (night), 31 (maximum robustness)

And for 16-QAM:

• 5 khz == 8 (day), 6 (night), 5 (maximum robustness)
• 10 kHz == 18 (day), 14 (night), 11 (maximum robustness)
• 20 kHz == 38 (day), 29 (night), 23 (maximum robustness)

Now, how am I going to put that confusing mess into the HD Radio comparison, in such a way that the average Joe Smith can understand it. Hmmm. - Theaveng 14:12, 28 September 2007 (UTC)

QUESTION 1: Do most DRM broadcasters use 64-QAM or 16-QAM? Thanks.

QUESTION 2: Do most DRM broadcasters use 64-QAM or 16-QAM? Thanks. - Theaveng 14:40, 28 September 2007 (UTC)

OFDM system comparison table

Feel free to add a DRM column to the OFDM#OFDM system comparison table. Mange01 11:48, 17 July 2007 (UTC)

Broken Link under DRM in General section

The link for "A Listeners' Guide to Digital AM (DRM)" gives me an error 404.

216.230.101.253 19:10, 15 August 2007 (UTC)

Fixed.

24.81.130.107 09:25, 28 September 2007 (UTC)

DRM+ for Airband?

I corrected the article to say DRM+ goes up to 108Mhz - not 120 - but the Airband page mentions a possible switch to digital radio. Would this be DRM+ or something else? 108 - 118Mhz is generally used for radio navigation equipment such as VOR and ILS and while they'll eventually be replaced by some enhanced GPS system (which will probably free that band for voice comms) that won't be soon. 118-137MHz is AM voice comms (CD quality not required) with 25kHz channel spacing (and Europe looking to reduce that to 8.33kHz) Anyone have any more info? Johnnie Rico (talk) 01:12, 2 February 2009 (UTC) DRM is a lost cause i think. I like the idea in general however all the software to decode it is patented and copyrighted etc. That is a very bad start. If you want people to really use it then there must be free software to decode the transmissions, why is DW not providing free software for example? So the whole thing is a nonsense. Even looking for information on DRM turns up very little. There is no clear explanation of what it is about or what extra services you get. This thing will float like a lead balloon. If they had put a bunch of services in it like ham radio SSTV, rolling text, free music and news file etc and each radio station providing DRM had some free decoding software for you then at least some people might use it. I think the German tax-payer is getting hit hard enough bailing out corrupt countries as it is without having to shell out for nonsense like this. German's don't always make smart choices obviously... — Preceding unsigned comment added by 113.190.206.204 (talk) 01:43, 10 October 2011 (UTC)

Seems dead

This (DRM) seems dead? I looked for DRM receivers and found two: one is definitely out of stock, the other on indefinite hold. Only Voice of Russia seems to have DRM emissions.--Xyzt1234 (talk) 16:05, 27 July 2011 (UTC)

You didn't look hard enough! VoR is indeed a player, so is BBC World Service, Radio Romania International and Vatican Radio. And that's just off the top of my head. I listen to BBC World Service News on 5790 kHz DRM quite regularly. Mind you, I did have to build my own radio and run it through the "Dream" software. You're right that it's difficult to buy a DRM radio, but they exist at least in Germany. And Germany seems to be the target for most DRM transmissions in Europe. I'm in the UK. Just about no DRM transmissions are aimed my way, but the BBC World Service is usable here just because it comes from only 350 km away. Steve Hosgood (talk) 00:06, 2 March 2012 (UTC)

Agree-- I cannot speak for elsewhere, but in the United States young people are not listening to any form of radio; they stream from the internet. The one major exception is in the automobile, where AM talk shows are popular (e.g. Rush Limbaugh). But many new cars in the US come with XM-Sirius satellite receivers as standard equipment. Of course you have to pay, but, people who drive a lot do not mind.

Relevant?

Quote: 2011 the paneuropean organisation Community Media Forum Europe [14] has recommended to the European Commission that DRM+ should rather be used for small scale broadcasting (local radio, community radio) than DAB/DAB+.

Interesting maybe, but is this relevant for a encyclopedic article? Maikel (talk) 20:47, 12 May 2013 (UTC)

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Analog?

The title Digital Radio Mondiale suggests that there is an alternative Analog Radio Mondiale, but as far as I know, there isn't. Should there at least be a redirect from Radio Mondiale? Gah4 (talk) 11:18, 11 December 2019 (UTC)

Bandwidth?

That section states for example "9 kHz. Occupies half the standard bandwidth of a region 1 long wave or medium wave broadcast channel." 9 kHz is the full bandwidth of a region 1 AM channel, all items after 4.5 and 5 kHz in this section make this error. In practice a DRM is always using the bandwidth it's specified with, on shortwave the DRM transmissions are 10 kHz wide and therefore occupy twice the bandwidth of a standard shortwave broadcast channel. 2A01:598:A003:6BCC:692B:7860:81D:3D0C (talk) 11:05, 14 November 2022 (UTC)