Talk:Digital Audio Broadcasting

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Number of FM stations - incorrect information[edit]

The following section is mistaken: Numerical example: Analog FM requires 0.2 MHz per programme. The frequency reuse factor in most countries is approximately 15, meaning that only one out of 15 transmitter sites can use the same channel frequency without problems with co-channel interference, i.e. cross-talk. Assuming a total availability of 102 FM channels at a bandwidth of 0.2MHz over the Band II spectrum of 87.5 to 108.0 MHz, an average of 102/15 = 6.8 radio channels are possible on each transmitter site (plus lower-power local transmitters causing less interference). This results in a system spectral efficiency of 1 / 15 / (0.2 MHz) = 0.30 programmes/transmitter/MHz. DAB with 192 kbit/s codec requires 1.536 MHz * 192 kbit/s / 1,136 kbit/s = 0.26 MHz per audio programme. The frequency reuse factor for local programmes and multi-frequency broadcasting networks (MFN) is typically 4 or 5, resulting in 1 / 4 / (0.26 MHz) = 0.96 programmes/transmitter/MHz. This is 3.2 times as efficient as analog FM for local stations. For single frequency network (SFN) transmission, for example of national programmes, the channel re-use factor is 1, resulting in 1/1/0.25 MHz = 3.85 programmes/transmitter/MHz, which is 12.7 times as efficient as FM for national and regional networks.

There are numerous examples, ranging from the United States to Italy to Greece to Turkey, where dozens of FM radio stations operate at full power (several kw or more) from the same transmitter site, without any "cross-talk" or interference. In Athens, most FM stations are spaced 0.3 MHz apart and most operate from the Mount Imittos transmitter farm. In Istanbul, most FM stations are spaced 0.2 MHz apart and most operate from the Camlica transmitter farm. Therefore the above information is entirely inaccurate and must be removed or corrected. — Preceding unsigned comment added by 2A02:587:2912:B400:95B5:A587:57E3:925F (talk) 11:51, 4 February 2018 (UTC)[reply]

A belated reply to this. I have been editing this page and have reached this section. There are certainly some factual errors in this section. Starting from the beginning, analogue FM requires almost 0.3MHz per programme. Then DAB bit rates are variable and rarely as high as 192kbps (unfortunately). There are a number of other errors which make it inaccurate. I would favour deleting this numerical example completely, although someone has put some work into creating it.Davidbstanley (talk) 09:03, 31 October 2018 (UTC)[reply]

Difference between DAB and FM[edit]

The sentence which begins "Whilst the RF medium alone is strictly analog..." is just asking for complicated misunderstandings. You can't specify a medium as being analogue or digital, it is irrelevant. Would you call a piece of paper an analogue medium ? If I draw a picture on it, maybe, but I could equally well write down a set of numbers to describe the picture.— Preceding unsigned comment added by 86.130.242.87 (talk • contribs) 02:37, 5 Mar 2006 (UTC)

Analog media can, and often does, store digital data. Many early microcomputers stored data on analog cassette tapes. In the early days of CD, video tape, holding a video format signal, was used to store the digital data for a CD master. Gah4 (talk) 07:05, 1 April 2022 (UTC)[reply]

DAB+ in Hungary[edit]

"Hungary is due to launch DAB+ stations in 2008..."

This sentence is now dated. I was not able to find any DAB+ rollout news in Hungary after a couple google searches. Anyone know the status?— Preceding unsigned comment added by Mburns (talk • contribs) 23:12, 15 Feb 2009 (UTC)

First[edit]

"DAB reception quality first degrades rapidly when the signal strength falls below a critical threshold..."

What does this mean? One expects it to say "DAB reception quality first degrades rapidly and then improves even more rapidly..." or something like that.

Alternatively, it was written by someone whose first (and only) language is Swedish, in which case the translation into English would be

"DAB reception quality degrades rapidly only when the signal strength falls below a critical threshold..."

This is still awkward, however. Could it be that DAB reception does not deteriorate at all (or only barely) with signal strength until the signal strength reaches a critical threshold, at which point it deteriorates rapidly as the signal weakens further? I don't know, because I don't know anything about DAB radio. That's why I was reading the article.

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DAB is a proper noun[edit]

Hello, it's not correct that DAB is a "generic, common term, not a propriety or commercial term". DAB is a digital radio standard, HD Radio is another, Digital Multimedia Broadcasting is another. --NaBUru38 (talk) 20:52, 27 May 2018 (UTC)[reply]

Correct. "Digital Audio Broadcasting" - better known as DAB - is a specific standard. "Digital audio broadcasting" is a generic phrase that could refer to any type of broadcasting audio digitally. -ProhibitOnions (T) 16:10, 30 October 2019 (UTC)[reply]

PURE and power[edit]

I bought a PURE Evoke-3 back in about 2004. It's quite a pretty device, with a good tone. BUT it tore up a set of 6 D cells in about an hour; that was going to bankrupt me, so I spent a quarter of the purchase price of the radio on a rechargeable PURE battery pack.

Well, that would last about 20 minutes, from fully charged to completely silent. It never lasted long enough for a bath and a shave. Even on FM, battery depletion was precipitous. I can only practically use this radio on mains power.

PURE's claims of 10-hour DAB operation on batteries for early models are not credible in my experience. I realise this is WP:OR, but repeating PURE's claims without secondary sources is WP:PROMOTION. I propose to remove from this article all claims concerning battery life, that are not supported by reliable sources (i.e. sources that have performed their own tests, and are not the manufacturer). I don't mean to restrict myself to PURE's claims; I regard any claims concerning battery life that are not supported by 3rd-party tests as eligible for deletion. MrDemeanour (talk) 14:33, 11 November 2018 (UTC)[reply]

I never owned one, but I do know that the battery life was grim. They could teach the mobile phone manufactures a thing or two about exaggerating battery life. So I would be happy to see the references removed.Davidbstanley (talk) 14:47, 11 November 2018 (UTC)[reply]

higher transmission cost[edit]

The article mentions higher transmission cost. Could someone explain what part of transmission cost depends on bit rate? Gah4 (talk) 07:07, 1 April 2022 (UTC)[reply]

This whole article needs to be refreshed I think[edit]

This article is quite messy so far as Wikipedia goes. First of all there is of course the issue of unreferenced sections. But also importantly the format doesn't read right. There is a 'History and development' section that is messy and also shows technologic info about DAB+. There's a bunch of info on Technology but it really blends the lines with 'DAB and AM/FM compared', 'Sound quality', and especially 'Strengths and weaknesses'. It feels like every section deals with multiple topics at once.

Right now it doesn't really feel and read like a good quality Wikipedia article so far as format goes. It needs a major change I think. Does anyone have suggestions how to do go ahead? Because even I myself am lost what needs to be done to improve. 85.255.236.102 (talk) 16:16, 26 June 2023 (UTC)[reply]

broadcasts a single multiplex that is approximately 1.5 MHz wide[edit]

The article says: broadcasts a single multiplex that is approximately 1.5 MHz wide. In US English, multiplex is usually an adjective. (Multiplexer is a noun, common in digital logic design.) Am I missing something here, or is this common in non-US English? Gah4 (talk) 23:49, 15 September 2023 (UTC)[reply]

Multiplex is commonly used as a noun in this situation and many others where more than one signal is carried through a medium. Here is an example of the UK government regulator using it in this DAB context [1] Davidbstanley (talk) 09:38, 17 September 2023 (UTC)[reply]
In US English, it is either carrier or subcarrier. And normally only when there is more than one subcarrier, otherwise it isn't multiplex. (That is, more than one.) I suspect it is commonly used in the US as short for multiplex cinema, though. Is carrier and subcarrier wrong in non-US English? Gah4 (talk) 12:22, 18 September 2023 (UTC)[reply]
I would not say carrier and subcarrier are wring, just it is more common here to use multiplex as a noun for these purposes. Another example, here the input to a FM transmitter is often referred to as multiplex whereas in the US it is more typical to say composite. We are used to dealing with both names, so it creates little confusion. Davidbstanley (talk) 05:45, 19 September 2023 (UTC)[reply]
For FM, there are the stereo subcarrier and SCA subcarrier. In the case of stereo, the combination is often enough described as multiplex or more usual, multipliexed. But mono FM would not be multiplex, and especially there is no single multiplex, as multiplex implies more than one. Single would be uniplex, though that is rare, or sometimes simplex. OK, for FM there would be the stereo multiplexer, which might be one box, and then the output of that goes to the FM transmitter. The multiplexer is a physical thing that you can touch, and sometimes pick up. The circuit in the FM receiver is, then, the stereo demultiplexer, though often enough just stereo decoder. Gah4 (talk) 09:47, 19 September 2023 (UTC)[reply]
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