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Archive 1 | Archive 2 |
This page now incorporates content formerly on Digital Audio Broadcast. I combined and edited the material for continuity, but I don't vouch for accuracy or objectivity. RussBlau 20:43, Apr 5, 2005 (UTC)
was merging a good idea? I thought one page was only for DAB whereas the other was for digital radio in general. Mavros 01:31, 6 Apr 2005 (UTC)
Some of this article sounds a little too POV, regarding the quality issues demonstrated by DAB/Eureka147. 86.134.80.40 19:41, 16 December 2005 (UTC)
P.S. can someone stop deleting this discussion about 'DAB in the UK' - cheers Anon Dude 17:41, 24 July 2006 (UTC)
Anon Dude, all the UK hi-fi magazines are in agreement that DAB sounds worse than FM, and people that understand the technology all agree that DAB sounds worse than FM, so why are you disputing this?
If hi-fi magazines and broadcasters agreed (that the sound is worse on 128k digital than analog FM), then you'd have a case for neutrality. But hi-fi magazines by themselves represent a range of opinions somewhat narrower than the whole of concerned parties, despite their experience and scientific means of analysis. Perhaps the statement could include a phrase like, "Although DAB has the potential to deliver high quality sound, most UK broadcasts are being sent at 128k which is considered lower quality than traditional FM." Then one could provide references from a couple of hi-fi magazines.
I would suggest that the criticism of the 128 rate in the UK may belong in a section some way down the article which could be about criticisms of particular DAB-implementations. However, in the first paragraph it seems to be zooming in on too much detail and/or POV. Also, the UK is European. www.danon.co.uk 20060904
Another Anon Dude - does anyone have any dates for FM being switched off?? To me this is going to be far more problematic than switching off analogue TV! The sheer number of radios in the UK (several per household, one in every car, several in every office [possibly small/portable], portable radios, ...) in comparision to the number of TVs (several per household [at most]) will make the task harder. Furthermore the advantages of FM to DAB don't seem all that great (?) whereas digital TV gives extra channels. Okay, there are extra DAB channels - but who cares? The extra TV channels seems more advantageous (?!)
That section may have to be deleted completely. There is ongoing discussion on removing criticism from articles because they violate WP:V and WP:NPOV. See Wikipedia:Criticism and Wikipedia:Templates for deletion#Template:criticism-section. Sorry folks, if it can't be verified with reliable sources and if conensus and Jimbo Wales is to go by, it's all gotta go. -- tgheretford ( talk) 16:23, 13 May 2007 (UTC)
could you please give some link about DAB2? -- Pejman47 10:53, 10 October 2006 (UTC)
The orthogonality section is incorrect. "Orthogonal" does not mean that two waves have a 90 degree phase difference (in quadrature). And in OFDM, sub-carriers are not in quadrature with each other - this is in fact impossible because they're at different frequencies, so talking about phase difference is meaningless!
The reason the sub-carriers are orthogonal is because the frequency difference between any two is a multiple of the reciprocal of the symbol period - and do therefore "integrate to zero" over one symbol period. See OFDM#Mathematical description to see how this works.
Oli Filth 11:55, 22 October 2006 (UTC)
I have made some edits to improve the overall Pov and neutrality. This should acknolowedge the different opinions of DAB but keeps them in an objective viewpoint. There were a number of subjective opinions thrown in which are still acknowledged but retained in a relevant section
81.98.161.0 13:22, 22 October 2006 (UTC)
Added POV tag to critisms. The point of the article should be to clearly state what DAB is, how it works, where it is implemented and how (technically). By definition, comments on quality are a point of view. The anonymous proponent of this section has removed this tag previously by ascertaining that 'they are facts with citations'. While I dont doubt that, they are still facts to support that POV. Comments such as "are worse than" are clearly subjective and we really dont need comparisons in the article at all. Otherwise we will end up comparing everything. Smiker 17:25, 4 November 2006 (UTC)
One or more users are continually adding POV tags to cast doubt on the validity of the information. This user or these users began by asking for references to the claims, which were duly given, and yet still this user or these users are adding POV tags. For example, the references for the issue of audio quality are to some of the most respected broadcasting research organisations in the entire world -- such as the BBC R&D department and the Communications Research Centre in Canada, and yet this user who seems to think he knows better than these people just adds a POV tag to cast doubt on these findings.
Listening tests that have been internationally standardised allow for objective quality measurements, and doubts raised over these "POV" issues have all been qualified by references, so there is no POV issue here.
Furthermore, to suggest that the phrase "is worse than" cannot be used is simply ridiculous. For example, would you have a problem with someone saying that a dial-up Internet connection at 56 kbps provides a worse user experience than a broadband Internet connection?
One of the main selling points of DAB has been that it claims to provide better audio quality, and there is such a claim in the first paragraph of this page, where it says that DAB was designed to offer enhanced fidelity. It is a fact that the audio quality on DAB is lower than on FM, and this has been proven by listening tests, so it is correct to point out that the claimed enhanced fidelity hasn't actually materialised. — Preceding unsigned comment added by 82.3.254.113 ( talk)
In response to Smiker: You have continually added POV tags to this page. At first the reason you gave was that no references were given for facts that had been provided. I added references for each request. And now that you seem to have run out of requests for references, you've started doubting the POV of the whole page.
If anybody has a POV here it is you. Why would anybody object to facts (with references) being put on a Wikipedia page unless they had some POV?
98% of stereo stations on DAB in the UK use 128 kbps MP2, and 128 kbps MP2 provides lower audio quality than on FM. That is a FACT.
You mentioned genocide, and that it doesn't say that it's a bad thing. The killing of a large group of people based on their ethnicity is so obviously a bad thing that it doesn't need to be said. In contrast, DAB is advertised as providing better audio quality, and Ofcom-commissioned market research showed that by far the most-cited "main advantage" of digital radio by people that listened via analogue radio was that they expected it would provide higher audio quality.
Let's use a more appropriate analogy to your genocide one: Say if Concorde was still flying. Most people will already know that it can break the sound barrier, and those that don't know this will read it in the first paragraph. However, if Concorde almost never actually breaks the sound barrier when it flies, and if you can provide a reference to something that verifies this, then why would that not be relevant to a page about Concorde? That is a perfectly reasonable fact to give.
The same is true for DAB. DAB was originally meant to provide higher audio quality than FM, and virtually everybody expects it to provide better audio quality than FM, but the simple fact is that it does not actually provide better quality in practice - it provides worse quality. And I'm sorry, but I fail to see how saying this on this page is in any way POV - it is a simple statement of fact, and backed up by references.— Preceding unsigned comment added by 81.107.209.177 ( talk)
"4. It follows the neutral point of view policy. In this respect: (a) viewpoints are represented fairly and without bias; (b) all significant points of view are fairly presented, but not asserted, particularly where there are or have been conflicting views on the topic"
When I used the hypothetical analogy of Concorde not breaking the sound barrier, the only point of the analogy was to look at another example where the performance that would be expected by the majority of people to be provided actually wasn't being provided in practice, and it would, therefore, be perfectly correct to refer to this on a Wikipedia page.
Your analogy is comparing the number of seats on Concorde and a jumbo, which has nothing to do with the expected performance of an aeroplance - I was using the performance parameter of speed.
And I've thought of a far more relevant analogy: the VHS vs Betamax format war. VHS beat Betamax in the format war, but ask *any* BBC engineer which provides the better picture quality and they will say Betamax. And looking on the Wikipedia page for Betamax, it says precisely that:
"A multitude of technical drawbacks along with the proprietary nature of the Betamax format hurt it in its competition with VHS, in spite of the Betamax's superior video quality"
So, ask yourself why it is perfectly fine to say that Betamax provided superior video quality and it's not okay to say that FM provides superior sound quality. I'll tell you why people have a problem with the *fact* that FM sounds better than DAB: the people who are opposed to this fact being presented on this page own a DAB portable radio and quite like DAB. Hence, the people who are deleting this unfortunate fact are the ones displaying a POV, not me - they're basically censoring the information on the page. This isn't North Korea, and facts should not be deleted just because some people don't happen to like the facts.
You know, I wouldn't mind if the audio quality on DAB and FM was close, but FM sounds miles better than DAB. I review DAB/FM tuners and DAB/FM portable radios for a UK hi-fi magazine, and the difference in audio quality between the two systems is enormous - Radio 3 is the only radio station that uses 192 kbps, and that sounds better on FM, so trying to cast doubt overy whether 128 kbps MP2 sounds worse than FM (which I've given a reference for as well) is simply laughable.
This is a *fact* backed up by a reference. So deleting this fact is simply POV and censorship.
To JMcc: You complain about "detailed information" being in the summary, and yet you leave in the sentence that says that DAB was originally designed to provide "higher fidelity". It is simply censorship to leave in the summary the fact that it was originally meant to provide higher fidelity and delete the fact that it doesn't actually provide this promised higher fidelity in practice.
Could you also tell me what gives you have the right to tell me not to edit the page??
My edit was nothing to do with censorship. My reasoning is:
Firstly, just because I have not registered does not mean I have not been adding content to Wikipedia for some time, and I am aware simply from reading Wikipedia pages what the general structure should be. And the credibility of the content I add should stand on its own without my having to register first to gain credibility from others. I don't provide incorrect information.
And the term "DAB" is really just synonymous with the Eureka 147 system now. The term used to be used in America, but they seem to have stopped using it now, probably because the acronym is the name used for the Eureka 147 system. So I don't think systems used in the US are relevant on a page about DAB - they should be linked to from a page about "digital radio".
You also have to consider that DAB has only started selling in any quantity in the UK and Denmark, and both of these countries provide audio quality inferior to on FM due to the bit rate levels used. Furthermore, because of the inefficiency of the MP2 audio codec, which has to be transmitted at very high bit rates to match FM-quality (224 kbps is usually equated to FM-quality), DAB basically sounds worse than FM in all countries - with the possible exception of Estonia, where the handful of stations are transmitted at 256 kbps.
So I'm afraid that continually deleting the fact that the audio quality on DAB is worse than on FM is in actual fact simply censorship.
Okay, I've now registered. The problem I have is that if you have a section titled "benefits" - whether prefixed by "claimed" or not - it's going to read like an advert for the technology, and that's exactly how it does read. And on the subject of the page being about Dab rather than DAB, the vast majority of the page is about DAB, so the name of the page needs to be changed to DAB (or Digital Audio Broadcasting) to reflect this, and there should be a separate more general page for Dab. HD Radio, DVB-H, DVB-T, DMB, FM, etc, all have their own pages, so DAB should have its own page too. 82.3.84.224 19:09, 14 November 2006 (UTC) Sorry, must have signed out, but I've signed in now. Digitalradiotech 19:10, 14 November 2006 (UTC)
A huge problem with this DAB article is the massive influence from british writers writing on british deatails regarding sound quality. As I understand, DAB can sound worse than FM in Great Britain, but rememeber that the UK is not the only country whit DAB transmissions. For instance, Norwegian listeners has benefitted from a grat increase in sound quality through DAB. Several technical publications in norway has written positive articles on DAB and DAB sound quality, like this editorial from Norwegian journal heavyweighter Teknisk Ukeblad [1].
This article currently stinks of some personal axe grinding by a small group of people (or maybe just one person?) in one geographical region. The whole issue of DAB quality needs to be kept in one small section of the article IMO though this could be referenced in the intro. I'll have stab at this over the weekend - I'm sure it can be done in a way that's informative, NPOV and looks far more professional than it does currently. However, as the information I added on the high-level of listener satisfation with DAB quality in the UK, along with reference to a well conducted survey, was removed by an anon editor, I suspect that this article will remain a mess due to someone wanting it to simply be a slur on DAB. -- Ian 08:05, 19 April 2007 (UTC)
My addition of links to favourable user surveys to the "Criticisms" section seems to have survived (for now!) but my removed of the criticisms from the into (where they do not belong IMO) was reverted without debate or comment. In the intro I had, "However, as with any digital transmission system, quality depends on the bitrate used, and there have been criticisms of the low bitrates used for DAB in some territories. See Criticisms Of DAB.", which I think is informative, balanced, NPOV and leads people to the criticisms if they are interested rather than forcing them down the throat of those just wanting to learn about DAB. What do others think? Should this article (or any article really) open up with detailed criticisms rather than starting with a balanced overview? -- Ian 12:20, 19 April 2007 (UTC)
Some contributors feel very possessive about material (be it categories, templates, articles, images, essays, or portals) that they have donated to this project. Some go so far as to defend them against all intruders. It is one thing to take an interest in an article that you maintain on your watchlist. Maybe you really are an expert or you just care about the topic a lot. But if this watchfulness crosses a certain line, then you are overdoing it. Believing that an article has an owner of this sort is a common mistake people make on Wikipedia.
You cannot stop everyone in the world from editing "your" stuff, once you have posted it to Wikipedia. As each edit page clearly states:
If you don't want your material to be edited mercilessly or redistributed by others, do not submit it. (emphasis added)
In addition to the two technical sections that have been identified to merge to their articles, I think it would be good to move the list of frequencies to a seperate page. Any comments? Smiker 18:05, 22 October 2006 (UTC)
This section seems to have been written on the basis of a single user's experience and/or what he has read in advertising material for the DAB system. It is therefore a POV section rather than containing reliable and/or verifiable facts.
The author of the section fails to understand how OFDM works. In particular, OFDM can not eliminate the problems associated with multipath propagation, which seems to be the main thrust of the section. And DAB receivers do not go from a state of effectively perfect reception to muting in one small step - there is a relatively large transition, with receivers producing a "bubbling mud" sound in between what appears to be perfect reception and full muting. Some would describe this as DAB having a "shallow digital cliff". FM, on the other hand, "degrades gracefully", and it may or may not result in the signal being "swamped by noise" - situations that could lead to DAB reception failing may not give rise to FM reception failing, because DAB is wideband and FM is narrowband, therefore you could have a situation where opposite ends of a DAB channel's bandwidth (1.5 MHz between them) are in a deep fade, which leads to too many bit errors, which leads to reception failing, and this would obviously not be a problem with FM because of its much narrower bandwidth.
Furthermore, describing FM reception as being "swamped by noise" is negative language, and yet the section uses no negative language for DAB reception - just that it mutes, which it doesn't anyway.
The issue of SFNs (single-frequency networks) also gives rise to problems with DAB reception that would not happen on FM, because FM doesn't use SFNs. Reception with SFNs is problematic when signals travel farther than intended, possibly due to lift conditions, but also due to terrain.
Mobile digital communications is a complex subject, and I would suggest that only those that actually understand the technology should write sections about it, and someone simply repeating what they have read in material provided by organisations seeking to promote this technology has no place on Wikipedia.
You wrote the whole section from your own experience, and you tried to explain why the claims about reception were correct. Merely adding the word "claimed" to the section title does not justify copying claims made in adverts onto Wikipedia.
Back home I have a bunch of back editions of the WRTH. One of them (I think it was the 2002 edition) lists in detail DAB, DRM, and WorldSpace. I'm planning on coming from university for the Christmas break anyway. If I can manage to bring it back to uni, I'll probably look through the WRTH section and fix the article accordingly. Would this work? - Daniel Blanchette 20:28, 29 November 2006 (UTC)
I hope folks like what I've done. Added a criticisms of DAB section - that was a major omission. POV requires both angles to be covered, so if there is a benefits section, logically a criticisms section must also exist. If I can add an opinion to the discussion page, DAB was a good idea, but using a codec such as MP2, which is well known for being poor at low bitrates, as DAB has been used in practice by broadcasters, was a simply disastrous decision. I'm delighted DAB are finally starting to admit their choice of codec was wrong, and are adopting AAC+. But why oh why did they spend several years trying to force a 'worse than FM' standard on us all? Thank goodness consumers voted with their feet, and refused to accept this rubbish. One of the biggest consumer standard fiascos I can recall, that has severely damaged the credibility of radio, in the eyes of the IPOD generation. Timharwoodx 13:31, 2 December 2006 (UTC)
Couldn't agree more. Digitalradiotech 23:41, 7 December 2006 (UTC)
Regarding the introduction text: "The original objectives of converting to digital systems were to enable higher fidelity, more stations, less inteference, mobile services and additional information such as text, although in practice the vast majority of radio stations on DAB sound worse than on [[FM]."
This does not sound like a balanced encyclopedic text, and only has a UK perspective (and perhaps only Eureka perspective). Many other countries, for example the Scandinavian countries, has offered 192 kbit/s and higher, which should be clearly better than FM. See [2] for a list of countries.
Those who claim that this text should be kept, please give references that support for that the text is valid outside UK.
The main advantage with DAB was that it did not suffer from fading to mobile listeners. In many European countries, for example Sweden, the FM transmitters have quite low power and are quite sparsely deployed, resulting in fading when you drive car on the country side. You mention interference, but co-channel interference may still be an issue in DAB.
I therefor suggest the following formulation "The objectives of converting to digital systems were to enable higher fidelity, more stations, less fading to mobile users, mobile services and additional information such as text and EPG, although some argue that since several DAB radio stations in some countries have lowered their bitrates in order to make available more stations, DAB can sound less superior than FM."
In Sweden we have called DAB = dead and buried for a long time, but I don't think that was because of sound quality issues, but because it did not give any interesting extra channels, because of poor coverage, and expensive receivers.
The section about "Criticisms of DAB standard" is a great idea. However, that section is not very well written. Why not take the above formulation by Timharwoodx into that section?
Mange01 01:41, 8 December 2006 (UTC)
Recently, the description of OFDM that was present in this article was moved verbatim into the OFDM article; this completely disrupted the OFDM article. I've reverted the removed text; it can be found on the talk page for OFDM. Oli Filth 21:31, 3 December 2006 (UTC)
The first sentence should say what the article is about. Given that the term 'digital audio broadcasting' has two meanings, this has to be said in the first sentence. The problems that this dual purpose causes perhaps should be solved by splitting the article into two: one called DAB (Eureka 147) and another called something like Digital audio standards. The urgency to point out the shortcomings of DAB in the second sentence would then look less odd. JMcC 12:31, 14 December 2006 (UTC)
I'm happy with the new Introduction written by JMcC, thanks for doing that. There's a couple of typos, but the content is correct, which is the important thing, and it is definitely right for the page to be about DAB rather than Dab, so thanks for doing that as well. Just one thing though, the URL still says Dab rather than DAB, so I think it would be a good idea to create a new DAB page and have the Dab page redirects to the new page.
I'll go through the Claimed Benefits with you when I've got a bit more time. Digitalradiotech 13:40, 18 December 2006 (UTC)
I agree with the current version of the sentence, which has not been written by myself, but my Mange01:
"The original objectives of converting to digital systems were to enable higher fidelity, more stations and more immunity to multipath than in analog FM radio. However the bitrate of 224 kbps [1] that is necessary to achieve adequate quality in MP2 is rarely used, and so in practice the vast majority of radio stations on DAB sound worse than on FM[2] for stationary reception."
I suggest we leave it there.
There is a temptation to put too much in the intro. The new third paragraph beginning "DAB is operated in Band III.." is fine except it should be in the main body. The intro just has to tell people the main gist of the article. Putting this much detail too early does not make for easy reading. Since there seems to have been agreement on my moving out of the non-DAB stuff, adding 224 kbps and some other improvements, I hope I will be trusted on this one as well. JMcC 19:29, 18 December 2006 (UTC)
I beg your pardon about adding 224 kbps - I thought it was Mange01.
I would obviously be against moving the audio quality issue out of the introduction.
Personally, I think the long introduction is good, because much of the rest of the page is, well, poor. Over half of the page is about country-specific implementations, and a lot of the content is out-of-date or hardly relevant. The UK, Denmark, Norway, Switzerland and Germany (in that order) are the only countries you ever really see mentioned on the Wohnort site - ironically, the first article on there is about Canada, but DAB is almost dead in Canada now that they've got 2 satellite digital radio systems operating. The rest of the world is basically uninterested, despite what some would have you believe.
People have said "DAB has been introduced in ..." Well, it depends what they mean by "introduced". For example, DAB was "introduced" in Sweden in about 1995, but in total I believe less than 1000 receivers have been sold! I don't call that introduced, I call that wasting electricity. And this applies to lots of countries - there's basically no interest other than the 5 mentioned above, and out of those, it's only actually selling in reasonable quantities (relative to population) in the UK and Denmark - it's apparently impossible to find a DAB receiver in the shops in Germany.
So I'd suggest that the introduction stays as it is, and the country-specific stuff is condensed, discarded or moved. Digitalradiotech 02:00, 19 December 2006 (UTC)
The original objectives of converting to digital transmission were to enable higher fidelity, more stations and more resistance to noise, co-channel interference and multipath than in analog FM radio. However, the bitrate of 224 kbps [1] per audio programme that is necessary to achieve a non annoying near CD music fidelity in the MP2 audio codec is rarely used, and so in practice the vast majority of radio stations on DAB sound worse than CD players. In fact, in some countries less than 160 kbit/s is used, resulting in worse musical fidelity than FM [2] for stationary reception. For mobile non-line-of-sight reception at far distance from the transmitter, for instance at highways in hilly terrain terrain, FM suffers from fading caused by multipath, and may sound much worse than DAB. On the other hand, DAB still has very poor coverage in rural areas in most countries, meaning that this advantage seldom can be exploited.
Mange01 00:03, 21 December 2006 (UTC)
First of all: sign up with Wikipedia, because you're anonymous at the moment. Secondly, this is not an advertisement for DAB, this is an encyclopedia, and "innovate" can only be used when something new has happened, but DAB has been transmitting since the mid 1990s, so it is one of the oldest wireless digital systems around, so no way on this earth can you use the word "innovate". Thirdly, your comment about "FM can sound pretty shitty" is a RECEPTION issue, but people get bad reception on BOTH DAB and FM, so you cannot use this. There are already caveats about FM's failings, and I've not objected to keeping them in.
At the end of the day, there is no getting away from the FACT that the broadcasters are letting radio listeners down by broadcasting sub-standard audio quality. Which begs the question: why on earth are you sticking up for them? Surely you want better quality too? All you are doing is trying to HIDE FACTS from anybody that wants to be INFORMED. If you think that 128 kbps MP2 or 160 kbps MP2 is anywhere near FM-quality then you are, I'm afraid, completely wrong.
If DAB was as good as you are trying to suggest it is, then it wouldn't have been upgraded to incorporate the AAC+ audio codec. It really can be boiled down to that. The old version of DAB is a poorly designed system which should have been upgraded in the 1990s, but wasn't. It is also on its way out now that DAB has been upgraded, so the sooner you realise this then the sooner we can both stop wasting our time arguing about a few words on a page on Wikipedia.
Now, I suggest we discuss the issue here so that we can come to some agreement on the wording, rather than playing ping-pong with the introduction. Digitalradiotech 16:32, 21 December 2006 (UTC)
And I'll add something further: if you are not able to justify what you've written on this dicussion page, then you simply should not write it in the first place. Your removal of the 99% figure is no different from a lie, because it is a verifiable fact with a reference provided. So either leave that 99% figure alone, or justify why you have changed it. The word "most" is inappropriate to describe a situation where the percentage is 99%. Digitalradiotech 19:43, 21 December 2006 (UTC)
I strongly believe that both benefits and criticism deserves a link in the intro. This is en encyclopdia, and should include an easy way to get the full insight in both pros and cons of the subject. If not a link to the benefits are to be displayed in the same sentence as the criticism, I suggest that everything from the second sentence and out should be removed from the intro. Right now i re intorduce the link, and then the users can voice the view here...(Regards, Segrov, 25th of december 2006)
To Sergov: apologies for removing your section on variable bandwidth - I reverted the Norwegian ranter's additions at the same time as you had added the section (see the times in the History), so your section got removed at the same time. I'll put the sub-section back in.
This article may as well be written by the guy from www.digitalradiotech.co.uk and is completly laughable. DAB, like all mass consumer technologies, is aimed at the mass market not a small minorety of Hi-Fi buffs. I agree with your removal of the constant bias of this article and hope you'll delete more of it.
I have added metainforamtion as a benefit of dab, because even though RDS in theory offers this is a feature, i still havent seen it implemented anywhere in Europe; to my knowledge neither Denmark, Sweden, Norway, Germany, The Netherlands, Belgium or Spain has these features in action, but the same countries offers this in their DAB implemetations. Also, most RDS iplementations i have experienced only offer the name of the station, not the name of the program name, the name of the artist, epg and similiar content. (Written by Segrov on the 25th of dec, 2006)
Shouldn't that belong in the L-band article? - Daniel Blanchette 20:53, 16 February 2007 (UTC)
I'm moving this text here from Talk:Dab. -- Geniac 08:02, 18 February 2007 (UTC)
DAB stands for Digital Audio Broadcasting. DAB is a digital radio system, which was developed by the Eureka 147 Project. It offers near CD-quality sound, more stations, additional radio and data services and therefore wider choice of programs, the ease of tuning and interference-free reception for the listener, plus the information potential of data, graphics and text. For the broadcaster, DAB provides a means of reaching listeners with sound quality on an equal footing with the CD player, and the ability to offer extra, potentially revenue-creating, services. Transmission will also be cheaper.
Over 475 million people around the world can now receive over 1,000 different DAB services. Commercial DAB receivers have been on the market since summer 1998. There over 250 different DAB receivers commercially available (as of August 2006) and the numbers continue to rise.
So whats Wrong With FM and AM?
We live in a digital world. Just about every communication process we engage in, from making a phone call to booking an airline ticket . FM was invented in the 1940s, AM in the 1920s. So radio is using a delidigital age. Furthermore DAB Digital Radio has many advantages and benefits for all concerned.very system that is anything up to 70 years old. DAB therefore is taking the oldest of broadcast media into the digital age.
Furthermore DAB Digital Radio has many advantages and benefits for all concerned.Digital Audio Broadcasting provides crystal clear sound that is comparable to near CD quality - you can hear music as though you're in a first class concert hall, or listen to a discussion programme as though you're right in the studio. Remember what vinyl LPs sounded like compared to CDs? That's the difference between analogue radio (like AM and FM) and DAB. DAB is almost immune to the sort of interference that can make listening to today's conventional AM or FM radio less than satisfying. If you listen to FM in the car, you may have noticed hisses and plops as you drive along. That's caused by multipath interference when the FM signal bounces off buildings, trees and hills and arrives at your receiver out of phase with the main signal, confusing the transmission. But DAB is revolutionary because inside the receiver is a computer which sorts through the myriad multipath signals and other distortions to enhance the main signal. This means that even in the most difficult listening environments-like the centre of a city with high-rise apartment and office blocks-the DAB signal remains absolutely perfect. DAB receivers are intelligent and smart. —Preceding unsigned comment added by Tom129 ( talk • contribs) 12:47, February 15, 2007
That reads like an advert to me. -
Daniel Blanchette
20:57, 20 February 2007 (UTC)
Hi, The unregistered user from IP 82.20.7.186 has reverted good faith edits. I tried to improve the flow of the text by converting bulletted sections into paragraphs. I am guessing that the IP 82.20.7.186 user may have penned these sections originally. User IP 82.20.7.186, Wikipedia editors are only supposed to use reverting for vandalism. When you submit text, it is on the understanding that other editors will trim it, copyedit it, modify it. If you want to have your text sit unedited on a webpage, get your own web page. This is a communal project. One person submits content, others re-draft it, trim it, add to it. I made "good faith" edits to improve the content. Much of the content was kept, because my edits were mostly about form and writing style, not content. Please consider registering IP 82.20.7.186, because it helps other users to chat with you. As well, it helps other users to assess an editor's credibility. When you edit as an anon user, we have no way of knowing if you are an experienced editor, or a person who has just made their first Wiki edit. Nazamo 17:02, 26 February 2007 (UTC)
There is far too much pointless reversion bouncing back and forward. If this doesn't stop, people are going to end up being reported for Three-revert rule. Please stop it; it doesn't help anyone. If there are differences of opinion on the article content, then discuss them here, rather than continually reverting back and forth.
It seems that the prime offenders currently are Digitalradiotech and 195.159.3.166.
Oli Filth 13:16, 7 March 2007 (UTC)
Here's the comparison between the two edits: [6], and I'll go through what is wrong with the points he makes below.
"Digital transmission techniques were developed because digital transmission has the potential to provide a higher fidelity,"We're not talking about "digital transmission techniques", that is a general area, we're talking *specifically* about DAB and why it was developed. It was developed to provide higher audio quality. It does not in reality provide higher quality.
"Unlike with FM, there is no hiss with a weak signal on a DAB signal." That implies that DAB is perfect with weak signals, which is nonsensical rubbish. DAB, like ALL wireless communication systems, displays problems when the signal is weak - this is by definition, because otherwise the signal wouldn't be described as being weak.
"However, most of the stereo stations in the leading countries using DAB (UK, Denmark, Norway and Switzerland) use a bit rate below 192 kbps MP2, which means that these stations sometimes can sound worse than FM for stationary reception of music on high-end HI-FI equipment". That is simply a massive, massive, massive misrepresentation of the truth. Firstly, I have provided references that showed that literally NINETY-NINE PERCENT of stereo radio stations on DAB in the countries mentioned use bit rates below 192 kbps, and yet User 195.159.3.166 changes this to "most". He also adds the caveat "on high-end HI-FI equipment" to try and suggest that FM only sounds better than DAB on very expensive equipment. Well, I write DAB/FM tuner and portable radio product reviews for a hi-fi magazine, and I can assure you that you can hear that DAB sounds worse than FM even on portable radios, which are the least capable radio devices in terms of their ability to reproduce high-fidelity, so if you can hear the difference on these then you can obviously hear the difference far more on all more capable devices. Basically, his caveat is nonsense.
"With mobile reception like a car stereo, DAB is usually better than FM, because FM stations' sound has problems caused by multipath interference, noise and co-channel interference." DAB is not "usually better than FM" in cars, and the sentence provided in the edit I prefer is correct: "With mobile reception, FM can suffer from fading caused by multipath, and can sound worse than DAB." Firstly, DAB sounds worse than FM on car stereos whenever there's no problems with FM reception, and the only time I notice any problems with FM reception in my car is when I'm travelling down the motorway at 70mph+.
stationary receivers, and DAB which is best in a car." [4] 195.159.3.166 16:45, 9 March 2007 (UTC)
"This means there are effectively now three different versions of the DAB system: the older one, developed in the late 1980s, and an upgraded version, which has been named "DAB+", as well as DABs multimedia sibling DMB". DMB is not a version of DAB (Digital AUDIO Broadcasting). DMB was designed for mobile TV use.
"Existing DAB receivers are incompatible with the new DAB standard unless they are upgradeable". Actually that can be changed now, because there is ONE DAB receiver that's just come out (the Morphy Richards 27024 DAB/DRM radio) that can be upgraded, but all the others cannot.
"Established DAB-countries like UK, Denmark, Norway etc have no plans in abandoning the established DAB standard." That's making an assertion about future events, and Switzerland is one of the "established DAB countries" and it has already advertised station slots using DAB+. Basically, if this sentences stays then it needs editing to be balanced. Digitalradiotech 11:08, 9 March 2007 (UTC)
I'd like to present the views of someone who hasn't been involved in this debate, and hopefully bring some further objectivity and neutrality to this. To state my credentials (as they seem to be important to some people here), I'm not an expert on DAB, although I have an MEng and do wireless comms DSP for a living, and have edited a wide variety of comms/DSP/maths Wikipedia articles. Here are my comments:
I hope this helps. I also hope that those involved in the current edit war would add their responses to my thoughts before engaging in yet more to-ing and fro-ing between the same two versions of the introduction. Oli Filth 01:18, 13 March 2007 (UTC)
I'm starting all these indentations again from zero, because all of the above has become too messy.
Right, Ga-David raises 2 issues: my "credibility" and what Professor Holm says. Firstly my "credibility". In terms of education, I have a 1st class MEng degree (that stands for master of engineering), an MSc in digital comms and DSP (subjects directly relevant to digital radio technology) and another 1st class undergraduate degree from the Open University that consisted of engineering and computer science subjects. Next, I write for a hi-fi magazine primarily about DAB, and I also write DAB/FM receiver reviews for the same magazine. And I've been "commentating" on DAB on my website since I set it up in March 2002, and my website has been calling for the use of digital radio systems that use the AAC+ audio codec and Reed-Solomon error correction coding for around 3-4 years -- WorldDMB has in the last few months finally announced the new DAB+ standard where DAB has adopted the AAC+ audio codec and RS error correction, i.e. precisely what I recommended 3-4 years ago. Oh, and my website popularised the name "DAB+" about a year ago, and lo and behold that's what they've called it.
I've been interviewed for articles in the Guardian (twice) and the Daily Telegraph, and my website has been mentioned by the Sunday Times. I've written articles about DAB for 2 of the leading Norwegian national newspapers -- one article was published a couple of weeks ago. I've been contacted via my website by people from the City asking for advice, as well as numerous broadcasters from around the world and people working on digital broadcasting, not to mention several hundred individuals saying how much they liked my website -- about 1200 or 1300 people have joined my newsletter. On a debate about DAB on a Radio 4 programme the person that was complaining about the audio quality on DAB quoted my website verbatim, and the French radio broadcasters also quoted my website pretty much verbatim in their responses to a consultation about digital radio -- which is pretty much the event that led to DAB+ being designed.
The only people that question my credibility are the DAB broadcasters. What an amazing coincidence that is. And I've also asked Ga-David more than once if he works in the Norwegian DAB industry, and he's ducked the question each time. So I'll ask again: Do you work in the Norwegian DAB industry? If you do work in the Norwegian DAB industry then I'm sorry but your industry is well-known for being dishonest, and if you don't work in the Norwegian DAB industry and you're just an ordinary listener that owns a DAB radio, then I suggest you learn some respect for people that understand this far better than you do.
And Ga-David himself even admits "Digitalradiotech probably has a lot of knowledge in DAB", but of course he qualifies this with "but unfortunaltely i can’t trust his information".
The TRUTH here is that FM outclasses DAB in terms of audio quality. I've reviewed virtually all of the DAB/FM tuners that are available in the UK, and the radio station I use to gauge how good or bad the tuner sounds is Radio 3, because that is the highest audio quality source on both DAB and FM. Radio 3 is the ONLY radio station on DAB in the UK that uses 192 kbps, and Radio 3 is the BBC's 'flagship' radio station in terms of audio quality. And the simple fact is that Radio 3 sounds significantly better on FM than on DAB.
Comparing technologies it should really be obvious that FM sounds better anyway. FM isn't all-analogue as most people seem to think it is. The signal that is distributed to the FM transmitters is digital: in the case of the BBC they use NICAM (724 kbps, IIRC), and the commercial radio stations use APT-X at 384 kbps or 256 kbps. So in reality, if you have good reception quality on both DAB and FM -- which is the only fair way to compare -- then you're really comparing MP2 at whatever bit rate the station uses with NICAM or APT-X at far higher bit rates. It's no wonder FM sounds miles better.
What's happening on here is simply people trying to hide the truth using technicalities. Digitalradiotech 16:34, 16 March 2007 (UTC)
This article is constanly being reverted by DigitalRadioTech who quikly removes all edits that conflicts with his personal opinion. When ever someone edits text to be less biased towards a DigitalRadioTechs "DAB is BAD"-attitude, the edits are simply removed by DigitalRadioTech. He often operates under different ip-addresses as well, but i’m quite sure that most of these edits are made by the very same person.
I, GA-David (aka 195.159.3.166), am trying to keep other users constructive edits, so therefore you will se me in the log where i am trying to revert some of the vandalism from DigitalRadioTech - even though i have been threathened by the him. I know, it is not a good situation, but if anyone have a suggestion, please put a note on my talk-page. Ga-david.b 08:49, 30 March 2007 (UTC)
This is getting absurd, so I've reported both User:Digitalradiotech and User:Ga-david.b for 3RR; see WP:AN/3RR. It's nothing personal, but this is the easiest way to stop this stupidity. Oli Filth 18:53, 30 March 2007 (UTC)
This article is about a specific technology. While it is unfortunate that the developers of that technology have chosen to hijack a pre-existing generic term for their specific system, the terms can at least be distinguished by capitalization. Digital audio broadcasting ought to redirect to digital radio and not to this article. 121a0012 20:07, 14 July 2007 (UTC)
Someone is over and over again destroying this article by removing correct technical facts and introducing biased formulations that never would be accepted even in a high school essay. For example "DAB+ will replace DAB in all countries that use DAB". Of course we can not know that for sure.
I once started to work on this article, but someone removed perfectly correct technical facts that I wrote, for example that DAB is based on statistical multiplexing, and the main principles of the transmission. So I gave up. And now I found that the article still is poor.
So please everyone, try to use a more objective language.
Some suggestions for improvements:
Mange01 08:45, 16 July 2007 (UTC)
I just re read the intro. It is completely comprised criticism of DAB - how in the world can anyone pass this off as an unbiased, relevant and appropriate introduction?
"The original objectives of converting to digital transmission were to enable higher fidelity, more stations and more resistance to noise, co-channel interference and multipath than in analogue FM radio. However, in the UK, Denmark, Norway and Switzerland, which are the leading countries with regard to implementing DAB, the vast majority of stereo radio stations on DAB have a lower sound-quality than FM[1][2] due to the bit rate levels used on DAB being too low[3][4]. This assumes that the listener has good reception on both DAB and FM, however, but FM can suffer from fading caused by multipath when the receiver is travelling at high speed which DAB is less prone to. For stationary reception, FM can suffer from hiss when the signal is weak, whereas DAB produces a "bubbling mud" sound when the received signal is too weak for proper decoding."
I suggest deleting this whole paragraph and rewriting the introduction. Please can others comment on this, thanks. Chrisp7 10:11, 25 August 2007 (UTC)
The lead is very poorly written. My recommendation for a new lead: "Digital Audio Broadcasting (DAB) is a technical standard for radio broadcasting technology which is used by stations in several nations, particularly in Europe. The technology requires new equipment to be used by both broadcasters and listeners. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format, covering a total potential listening audience of 500 million people.
Proponents claim the standard offers several benefits over analog FM radio: better sound quality, more stations in the same broadcast spectrum, and increased resistance to noise. In practice, critics claim, broadcasters' choice to use low bit rate options of the standard have meant that listeners actually get worse sound quality than with FM.
Additional technical standards, said to be more robust, are currently under development under the term DAB+. Although DAB+ re-uses the DAB acronym, existing generation DAB receivers will not be able to receive DAB+ broadcasts."
The remainder of the article also needs significant editorial review, and more inline citations. The History section should remove references to specific technologies such as MP2 and OFDM.
If there is a Wikipedia article about "format wars," this would be an appropriate example and cross-reference.
VisitorTalk 15:51, 25 August 2007 (UTC)
Support' VisitorTalk's version of lead - I cannot speak for accuracy, but it's a far more encyclopedic lead than what I'm currently seeing. There is no way round the new version being "advertising" of the format and it's wrong to put criticism of it in there (unless it's imminent danger of being wound up because it's widely agreed to be terrible!). PalestineRemembered 12:30, 11 September 2007 (UTC)
Digitalradiotech,
I'm sure you are aware that adding "those 94% of people are wrong" is completely inappropriate POV and original synthesis. If you aren't prepared to edit constructively, then please stop editing.
As for the links, yes, we're all aware they exist, and they're all already in the article at least once. The "sound quality" section already exists under "criticism", there's no need to repeat yourself.
Oli Filth( talk) 00:58, 13 November 2007 (UTC)
As for the latest edit comments, you know full well that you cannot meaningfully state that people's subjective opinions are "wrong". At any rate, this is original synthesis, as I've already pointed out umpteen times. Oli Filth( talk) 01:59, 13 November 2007 (UTC)
In complete contrast to this, however, a different poll about what people would like DAB to offer in future found that 92% of people would like DAB to provide higher audio quality than it does at present( http://www.digitalradiotech.co.uk/future_radio_poll.php ). This suggests that those who are content with the audio quality on DAB are unaware that they are being provided with audio quality that is worse than FM.
I've added a {{ splitsection}} tag to the Regional implementations of DAB section of the article. The article is currently 52kB in size, which is a little on the large size. The majority of this is contributed by the section in question, which in my mind, seems an ideal candidate for a standalone article. This would leave this article to be a discussion on the history/technical details/pros+cons of the DAB standard itself. Thoughts, anyone? Oli Filth( talk) 00:46, 15 November 2007 (UTC)
I disagree that in-depth info about DAB+ is "most important"; it's a standard that was only published this year, and isn't (AFAIK) yet being used anywhere, so undue weight considerations would apply here. By the "number of interested readers" argument, most would be interested in the existing system, for which the pros/cons/raison d'etre info is relevant (and normally expected in an article lead). Of course, these considerations may change in time, as interest, etc. in DAB+ grows. Therefore, I've rearranged the order, and attempted to incorporate the new additions as best I can, whilst also attempting to improve the readability.
As previously discussed several times, self-citing to this extent is frowned upon in Wikipedia, so please can we find some more independent sources to replace these links (Digitalradiotech, as you wrote the pages being linked to, presumably you know where this info originally came from and can provide suitable links or references).
I've removed the addition to the UK section, because as it stands, this interpretation is original synthesis. If "The reason why this happened is that DAB is a spectrally inefficient system, and because the broadcasters chose to squeeze too many stations onto the DAB multiplexes." can be independently sourced, then it can go back in. Oli Filth( talk) 19:39, 16 November 2007 (UTC)
DAB comes in several versions; the more common DAB, as well as the newly established DAB+, or the multimedia oriented DMB and DAB-IP.
As requested:
From a Wikipedia/article perspective, use of the word "arguably" with no source cited can only be construed as POV, I'm afraid (see also WP:AWW).
As far as the topic is concerned, as I've already suggested, it could also be argued that other system choices are equally critical for the performance of DAB. As far as spectral efficiency is concerned, the choice between code rates of 1/3 to 1/2 (for example) has as great an effect as the choice between codec rates of 128 to 192 kbit/s. Equally, differing choices of modulation scheme and pulse-shaping have significant effects on the spectral usage. The choice of interleaving depth is critical for the system's ability to cope with fast fading (i.e. the difference between it being usable in vehicles or not). The particular combination of all parameters directly affects system complexity, and therefore receiver power-consumption and cost, which are critical in a consumer application such as this. I'm sure you're aware of all this already, though. Oli Filth( talk) 14:51, 17 November 2007 (UTC)
Is is, deal with it, and you're showing your bias towards an area that you have a personal interest in by putting transmission above FEC coding. The things that matter to radio listeners are the content/stations, audio quality and reception quality, and FEC coding is the main determinant of reception quality, so stop trying to think you know better than me about digital radio technologies and their relative importance, because you don't.
The Error-correction coding section currently mentions that DAB+ uses Forney interleaving. However, the spec (ETSI TS 102 563) makes no mention of this; instead, all it describes is how the RS is performed on interleaved data, and that the data itself is forwarded in original order. On the other hand, the DMB spec (ETSI TS 102 427) does explicitly mention the use of Forney interleaving.
Does the article section need correcting? Oli Filth( talk) 14:06, 18 November 2007 (UTC)
Quoting from Computer Networks by Tanenbaum, section 1.4.1 "The OSI Reference Model":
"The physical layer is concerned with transmitting raw bits over a communication channel."
"The main task of the data link layer is to take a raw transmission facility and transform it into a line that appears free of undetected transmission errors to the network layer."
Basically, if you want to say it's in the phy then you have to remove the reference to the OSI stack, or you keep the reference to the OSI stack and put it in the data link layer. I'm easy, but as it stands it's incorrect. I'm going to undo your edit, but if you want to lump everything together as being in the phy then fine, so long as you delete the reference to the OSI model and the mention of the audio codec being in the application layer.
DigitalRadioTech, Here is the current paragraph in the intro:
DAB exists in several versions; the more established DAB, as well as the recent major revision DAB+ from 2006, and the video oriented DMB and DAB-IP wich is used for handheld tv broadcasts.
Will you be more happy with this? My concern is that the paragraph about DAB+ intro should be brief, and the we should go in depth on DAB+ in the apropriate section.
DAB exists in several versions; the more established DAB, as well as the recent major revision DAB+ from 2006, being approximately three times more efficient than DAB, but wich is not backward-compatible with the original standard. Several countries are expected to launch DAB+ broadcasts over the next few years. Also there is video oriented DAB versions DMB and DAB-IP wich is used for handheld tv broadcasts.
I believe Ga-david.b has edited from 195.159.3.166, at least from my reading of the 195.159.3.166 talk page [18].
Interestingly, 195.159.3.166 edited the Norwegian DAB article on 14 Nov 2006 [19] to include this sentence: "Men MP2-formatets fordel er at det har en større toleranse for feil bitfeil en mer kompakte om moderne formater som ACC+ og WMA, og dermed vil MP2 være bedre egnet for den norske topografien.". Roughly translated, this says "But the MP2-format advantage is that it has a greater tolerance for errors bit-errors than more compressed modern formats like ACC+ and WMA, and therefore MP2 will be better suited for the Norwegian topography". The current article has made some modifications to this sentence so it now appears as "Men samtidig har MP2-formatet også fordeler. F.eks. har det større toleranse for feil enn mer kompakte og moderne formater som ACC+ og WMA, og dermed vil MP2 være bedre egnet for den norske topografien hvor skog og fjell vil kunne gi ørsmå forstyrrelser.", which is roughly "But at the same time, MP2 format also has advantages, for example, it has greater tolerance for errors than more compressed and modern formats like ACC+ and WMA, and therefor MP2 is better suited to the Norwegian topography where forests and mountains will likely give greater problems (not sure how to translate "vil kunne gi ørsmå forstyrrelser")"
My understanding is that this is factually misleading (it is also uncited in the Norwegian Wikipedia), and that DAB+ using ACC+ actually has a greater tolerance of bit-errors than MP2 due to the additional use of Reed-Solomon encoding in DAB+.
The pdf here http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf gives an overview of the use of Reed-Solomon and AAC+.
Why this somewhat long screed? Well, I think Ga-david.b may be inadvertently incorrect in his/her knowledge of DAB and DAB+ and making good faith edits that are on the basis of incorrect knowledge/understanding of the subject matter. If that is true and we can correct that, then I'm sure the English article will benefit from that, *and* the Norwegian article (which would benefit from some citations and some minor rewriting)
Cheers,
WLD talk| edits 18:32, 20 November 2007 (UTC)
This article still has an enormous negative slant - my attempt to improve one small part a few months back (the introduction) have largely been in vain. The article makes continual references to the sourec of 1 individual who is in effect 'in control' of this page. A group effort is required to remove its bias and non neutral languange and references. Chrisp7 ( talk) 13:47, 2 February 2008 (UTC)
98% of stereo stations in the UK, Denmark, Norway and Switzerland (which are the only countries where DAB sales have taken off)
Those statistics are HEAVILY weighted by the UK having far more DAB stations. It's not fair to average an overwhelmingly large value with other tiny ones. I recommend either rewording the statement to single out just the UK as using 128kbit/s for audio, or using the worldwide averages instead, where the average bitrate is higher. "Taken off" isn't a useful or NPOV measure anyhow.
are using bit rates levels that are too low.
"Too low" for what and according to who? This is vague and inherently POV. I would suggest just specifying the relevant bitrates directly to make the point. More detail can be explained in the article, rather than putting so much in the intro.
DAB+ is approximately three times more efficient than DAB
This is oversimplified to the point of inaccuracy. That 3x figure seems due to the poor performance of MP2 at very low bitrates compared to HE-AAC. On further reading (of trev_305-moser.pdf) the figure is more accurately about 2X when using higher, more reasonable bitrates (ie. 96-128kbps). eg. "The bandwidth reduction for aacPlus transmissions compared to competing systems exceeds a factor of 2".
The choice of audio codec is one of the most important aspects in the design of a digital radio system,
Poorly worded and POV. I could just as well say modulation or error correction is the most important...
a network of transmitters can provide coverage to a large area - up to the size of a country
Liechtenstein or Russia? Not a useful metric...
I hope someone will work on these problems with the article. It's pretty good otherwise. If not, I'll eventually get around to it myself. Also, this huge talk page would benefit from being setup for auto archiving. Rcooley ( talk) 19:37, 31 March 2008 (UTC)
We're not interested. Coming into our area and BLATANTLY VANDALIZING and erasing several paragraphs of information that has been carefully written & supported by external references is NOT acceptable behavior. ----- Focus on your own backyard, and stay out of ours. DO NOT ERASE WHOLE PARAGRAPHS WITHOUT FIRST DISCUSSING IT in the talk page for hd radio. That is poor etiquette. ---- Theaveng ( talk) 14:02, 29 April 2008 (UTC)
I've edited the intro and removed text that might be deemed advertorial. I've also addressed all of the issues RCooley mentions above. I've also removed the text about GCap withdrawing its support for DAB and moved that to the Regional implementations of DAB page and put it in the UK section. I've slimmed down the section on DAB+.
I feel that the intro is now okay. Digitalradiotech ( talk) 09:55, 30 April 2008 (UTC)
Loren.wilton ( talk) 13:23, 30 April 2008 (UTC)
So, what are the specifics of DAB+? Canada's deployment of DAB calls for five music programs per channel, and an unknown (to me) number of non-music programs. The channels are 1.744 MHz apart. What are the comparable traits of DAB+? GBC ( talk) 01:40, 30 July 2008 (UTC)
Does it have copy protection? Towel401 ( talk) 00:47, 19 August 2008 (UTC)
Could somebody explain why, if DAB+ is far superior (as this article says), would RTÉ begin its DAB service this morning, 1 December 2008- http://blogs.rnw.nl/medianetwork/rte-to-launch-five-national-digital-radio-services- rather than a DAB+ service? I accept that RTÉ began its trial versions of DAB in January 2006, i.e. before DAB+ was released in February 2007. However, if the differences are so significant between both systems, why would they have not changed to the newer version by now, December 2008? Basically, I want to but a DAB type radio with Ipod dock, and I'm wondering which is the best system to buy now given the above. Thanks. 192.122.218.190 ( talk) 22:53, 1 December 2008 (UTC)
Does anybody know where one can find slimline DAB systems that have an IPOD dock? They all seem to be unnecessarily bulky- like something from the 1960s. What is the sense in such bulky designs in 2008? 78.16.192.72 ( talk) 23:28, 3 December 2008 (UTC)
"Hungary is due to launch DAB+ stations in 2008..."
This sentence is now iytdated. 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) 22:13, 15 February 2009 (UTC)
Is this article unbiased and balanced? Several people have over some time (a year or so) been complaining about a persons continous lack of will to change the introduction, as you might see from both the history as well as the talk-pages.
Yes. I certainly think so. Please fix. The opening is terrible. 124.157.251.100 ( talk) 09:22, 14 June 2009 (UTC)
Info (19 February 2009)
Info (19 March 2009)
Info (09 April 2009) —Preceding
unsigned comment added by
Kingdavid007 (
talk •
contribs)
14:28, 13 May 2009 (UTC)
The Intro starts by slamming DAB sound quality on a quite theoretical point of view.
Also, one of the main sources is http://www.digitalradiotech.co.uk/dab/worldwide_dab.htm but this site is somehow not thrustworthy. Have a look at the front page: http://www.digitalradiotech.co.uk/
Also, one of the other sources, the Norwegian doctor Sverre Holm ( http://www.duo.uio.no/sok/work.html?WORKID=52348), claims that the FM is comparable with 160kbits DAB transmissions, while the last source - David Robinson – is not available online, and also seems to have some sort of connection with the biased source
I have now removed the biased source, and adjusted the introduction a little to reflect the only reliable source, the Norwegian Sverre Holm. —Preceding unsigned comment added by 84.48.121.36 ( talk) 11:34, 16 November 2009 (UTC)
The Sound Quality section contains the following odd statement:
The UK government doesn't decide on transmission bitrates. This is largely decided by the BBC and OFCOM, neither of which are part of the government. The audio bitrate on digital TV channels varies (many use 128k), but it takes up a very small part of the total TV signal bitrate anyway and the subject is nothing to do with DAB.
I'm inclined to remove all this, as it contributes little to the article and is really just a confused grumble about low audio bitrates. Do others agree? -- Ef80 ( talk) 19:30, 3 December 2009 (UTC)
This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 | Archive 2 |
This page now incorporates content formerly on Digital Audio Broadcast. I combined and edited the material for continuity, but I don't vouch for accuracy or objectivity. RussBlau 20:43, Apr 5, 2005 (UTC)
was merging a good idea? I thought one page was only for DAB whereas the other was for digital radio in general. Mavros 01:31, 6 Apr 2005 (UTC)
Some of this article sounds a little too POV, regarding the quality issues demonstrated by DAB/Eureka147. 86.134.80.40 19:41, 16 December 2005 (UTC)
P.S. can someone stop deleting this discussion about 'DAB in the UK' - cheers Anon Dude 17:41, 24 July 2006 (UTC)
Anon Dude, all the UK hi-fi magazines are in agreement that DAB sounds worse than FM, and people that understand the technology all agree that DAB sounds worse than FM, so why are you disputing this?
If hi-fi magazines and broadcasters agreed (that the sound is worse on 128k digital than analog FM), then you'd have a case for neutrality. But hi-fi magazines by themselves represent a range of opinions somewhat narrower than the whole of concerned parties, despite their experience and scientific means of analysis. Perhaps the statement could include a phrase like, "Although DAB has the potential to deliver high quality sound, most UK broadcasts are being sent at 128k which is considered lower quality than traditional FM." Then one could provide references from a couple of hi-fi magazines.
I would suggest that the criticism of the 128 rate in the UK may belong in a section some way down the article which could be about criticisms of particular DAB-implementations. However, in the first paragraph it seems to be zooming in on too much detail and/or POV. Also, the UK is European. www.danon.co.uk 20060904
Another Anon Dude - does anyone have any dates for FM being switched off?? To me this is going to be far more problematic than switching off analogue TV! The sheer number of radios in the UK (several per household, one in every car, several in every office [possibly small/portable], portable radios, ...) in comparision to the number of TVs (several per household [at most]) will make the task harder. Furthermore the advantages of FM to DAB don't seem all that great (?) whereas digital TV gives extra channels. Okay, there are extra DAB channels - but who cares? The extra TV channels seems more advantageous (?!)
That section may have to be deleted completely. There is ongoing discussion on removing criticism from articles because they violate WP:V and WP:NPOV. See Wikipedia:Criticism and Wikipedia:Templates for deletion#Template:criticism-section. Sorry folks, if it can't be verified with reliable sources and if conensus and Jimbo Wales is to go by, it's all gotta go. -- tgheretford ( talk) 16:23, 13 May 2007 (UTC)
could you please give some link about DAB2? -- Pejman47 10:53, 10 October 2006 (UTC)
The orthogonality section is incorrect. "Orthogonal" does not mean that two waves have a 90 degree phase difference (in quadrature). And in OFDM, sub-carriers are not in quadrature with each other - this is in fact impossible because they're at different frequencies, so talking about phase difference is meaningless!
The reason the sub-carriers are orthogonal is because the frequency difference between any two is a multiple of the reciprocal of the symbol period - and do therefore "integrate to zero" over one symbol period. See OFDM#Mathematical description to see how this works.
Oli Filth 11:55, 22 October 2006 (UTC)
I have made some edits to improve the overall Pov and neutrality. This should acknolowedge the different opinions of DAB but keeps them in an objective viewpoint. There were a number of subjective opinions thrown in which are still acknowledged but retained in a relevant section
81.98.161.0 13:22, 22 October 2006 (UTC)
Added POV tag to critisms. The point of the article should be to clearly state what DAB is, how it works, where it is implemented and how (technically). By definition, comments on quality are a point of view. The anonymous proponent of this section has removed this tag previously by ascertaining that 'they are facts with citations'. While I dont doubt that, they are still facts to support that POV. Comments such as "are worse than" are clearly subjective and we really dont need comparisons in the article at all. Otherwise we will end up comparing everything. Smiker 17:25, 4 November 2006 (UTC)
One or more users are continually adding POV tags to cast doubt on the validity of the information. This user or these users began by asking for references to the claims, which were duly given, and yet still this user or these users are adding POV tags. For example, the references for the issue of audio quality are to some of the most respected broadcasting research organisations in the entire world -- such as the BBC R&D department and the Communications Research Centre in Canada, and yet this user who seems to think he knows better than these people just adds a POV tag to cast doubt on these findings.
Listening tests that have been internationally standardised allow for objective quality measurements, and doubts raised over these "POV" issues have all been qualified by references, so there is no POV issue here.
Furthermore, to suggest that the phrase "is worse than" cannot be used is simply ridiculous. For example, would you have a problem with someone saying that a dial-up Internet connection at 56 kbps provides a worse user experience than a broadband Internet connection?
One of the main selling points of DAB has been that it claims to provide better audio quality, and there is such a claim in the first paragraph of this page, where it says that DAB was designed to offer enhanced fidelity. It is a fact that the audio quality on DAB is lower than on FM, and this has been proven by listening tests, so it is correct to point out that the claimed enhanced fidelity hasn't actually materialised. — Preceding unsigned comment added by 82.3.254.113 ( talk)
In response to Smiker: You have continually added POV tags to this page. At first the reason you gave was that no references were given for facts that had been provided. I added references for each request. And now that you seem to have run out of requests for references, you've started doubting the POV of the whole page.
If anybody has a POV here it is you. Why would anybody object to facts (with references) being put on a Wikipedia page unless they had some POV?
98% of stereo stations on DAB in the UK use 128 kbps MP2, and 128 kbps MP2 provides lower audio quality than on FM. That is a FACT.
You mentioned genocide, and that it doesn't say that it's a bad thing. The killing of a large group of people based on their ethnicity is so obviously a bad thing that it doesn't need to be said. In contrast, DAB is advertised as providing better audio quality, and Ofcom-commissioned market research showed that by far the most-cited "main advantage" of digital radio by people that listened via analogue radio was that they expected it would provide higher audio quality.
Let's use a more appropriate analogy to your genocide one: Say if Concorde was still flying. Most people will already know that it can break the sound barrier, and those that don't know this will read it in the first paragraph. However, if Concorde almost never actually breaks the sound barrier when it flies, and if you can provide a reference to something that verifies this, then why would that not be relevant to a page about Concorde? That is a perfectly reasonable fact to give.
The same is true for DAB. DAB was originally meant to provide higher audio quality than FM, and virtually everybody expects it to provide better audio quality than FM, but the simple fact is that it does not actually provide better quality in practice - it provides worse quality. And I'm sorry, but I fail to see how saying this on this page is in any way POV - it is a simple statement of fact, and backed up by references.— Preceding unsigned comment added by 81.107.209.177 ( talk)
"4. It follows the neutral point of view policy. In this respect: (a) viewpoints are represented fairly and without bias; (b) all significant points of view are fairly presented, but not asserted, particularly where there are or have been conflicting views on the topic"
When I used the hypothetical analogy of Concorde not breaking the sound barrier, the only point of the analogy was to look at another example where the performance that would be expected by the majority of people to be provided actually wasn't being provided in practice, and it would, therefore, be perfectly correct to refer to this on a Wikipedia page.
Your analogy is comparing the number of seats on Concorde and a jumbo, which has nothing to do with the expected performance of an aeroplance - I was using the performance parameter of speed.
And I've thought of a far more relevant analogy: the VHS vs Betamax format war. VHS beat Betamax in the format war, but ask *any* BBC engineer which provides the better picture quality and they will say Betamax. And looking on the Wikipedia page for Betamax, it says precisely that:
"A multitude of technical drawbacks along with the proprietary nature of the Betamax format hurt it in its competition with VHS, in spite of the Betamax's superior video quality"
So, ask yourself why it is perfectly fine to say that Betamax provided superior video quality and it's not okay to say that FM provides superior sound quality. I'll tell you why people have a problem with the *fact* that FM sounds better than DAB: the people who are opposed to this fact being presented on this page own a DAB portable radio and quite like DAB. Hence, the people who are deleting this unfortunate fact are the ones displaying a POV, not me - they're basically censoring the information on the page. This isn't North Korea, and facts should not be deleted just because some people don't happen to like the facts.
You know, I wouldn't mind if the audio quality on DAB and FM was close, but FM sounds miles better than DAB. I review DAB/FM tuners and DAB/FM portable radios for a UK hi-fi magazine, and the difference in audio quality between the two systems is enormous - Radio 3 is the only radio station that uses 192 kbps, and that sounds better on FM, so trying to cast doubt overy whether 128 kbps MP2 sounds worse than FM (which I've given a reference for as well) is simply laughable.
This is a *fact* backed up by a reference. So deleting this fact is simply POV and censorship.
To JMcc: You complain about "detailed information" being in the summary, and yet you leave in the sentence that says that DAB was originally designed to provide "higher fidelity". It is simply censorship to leave in the summary the fact that it was originally meant to provide higher fidelity and delete the fact that it doesn't actually provide this promised higher fidelity in practice.
Could you also tell me what gives you have the right to tell me not to edit the page??
My edit was nothing to do with censorship. My reasoning is:
Firstly, just because I have not registered does not mean I have not been adding content to Wikipedia for some time, and I am aware simply from reading Wikipedia pages what the general structure should be. And the credibility of the content I add should stand on its own without my having to register first to gain credibility from others. I don't provide incorrect information.
And the term "DAB" is really just synonymous with the Eureka 147 system now. The term used to be used in America, but they seem to have stopped using it now, probably because the acronym is the name used for the Eureka 147 system. So I don't think systems used in the US are relevant on a page about DAB - they should be linked to from a page about "digital radio".
You also have to consider that DAB has only started selling in any quantity in the UK and Denmark, and both of these countries provide audio quality inferior to on FM due to the bit rate levels used. Furthermore, because of the inefficiency of the MP2 audio codec, which has to be transmitted at very high bit rates to match FM-quality (224 kbps is usually equated to FM-quality), DAB basically sounds worse than FM in all countries - with the possible exception of Estonia, where the handful of stations are transmitted at 256 kbps.
So I'm afraid that continually deleting the fact that the audio quality on DAB is worse than on FM is in actual fact simply censorship.
Okay, I've now registered. The problem I have is that if you have a section titled "benefits" - whether prefixed by "claimed" or not - it's going to read like an advert for the technology, and that's exactly how it does read. And on the subject of the page being about Dab rather than DAB, the vast majority of the page is about DAB, so the name of the page needs to be changed to DAB (or Digital Audio Broadcasting) to reflect this, and there should be a separate more general page for Dab. HD Radio, DVB-H, DVB-T, DMB, FM, etc, all have their own pages, so DAB should have its own page too. 82.3.84.224 19:09, 14 November 2006 (UTC) Sorry, must have signed out, but I've signed in now. Digitalradiotech 19:10, 14 November 2006 (UTC)
A huge problem with this DAB article is the massive influence from british writers writing on british deatails regarding sound quality. As I understand, DAB can sound worse than FM in Great Britain, but rememeber that the UK is not the only country whit DAB transmissions. For instance, Norwegian listeners has benefitted from a grat increase in sound quality through DAB. Several technical publications in norway has written positive articles on DAB and DAB sound quality, like this editorial from Norwegian journal heavyweighter Teknisk Ukeblad [1].
This article currently stinks of some personal axe grinding by a small group of people (or maybe just one person?) in one geographical region. The whole issue of DAB quality needs to be kept in one small section of the article IMO though this could be referenced in the intro. I'll have stab at this over the weekend - I'm sure it can be done in a way that's informative, NPOV and looks far more professional than it does currently. However, as the information I added on the high-level of listener satisfation with DAB quality in the UK, along with reference to a well conducted survey, was removed by an anon editor, I suspect that this article will remain a mess due to someone wanting it to simply be a slur on DAB. -- Ian 08:05, 19 April 2007 (UTC)
My addition of links to favourable user surveys to the "Criticisms" section seems to have survived (for now!) but my removed of the criticisms from the into (where they do not belong IMO) was reverted without debate or comment. In the intro I had, "However, as with any digital transmission system, quality depends on the bitrate used, and there have been criticisms of the low bitrates used for DAB in some territories. See Criticisms Of DAB.", which I think is informative, balanced, NPOV and leads people to the criticisms if they are interested rather than forcing them down the throat of those just wanting to learn about DAB. What do others think? Should this article (or any article really) open up with detailed criticisms rather than starting with a balanced overview? -- Ian 12:20, 19 April 2007 (UTC)
Some contributors feel very possessive about material (be it categories, templates, articles, images, essays, or portals) that they have donated to this project. Some go so far as to defend them against all intruders. It is one thing to take an interest in an article that you maintain on your watchlist. Maybe you really are an expert or you just care about the topic a lot. But if this watchfulness crosses a certain line, then you are overdoing it. Believing that an article has an owner of this sort is a common mistake people make on Wikipedia.
You cannot stop everyone in the world from editing "your" stuff, once you have posted it to Wikipedia. As each edit page clearly states:
If you don't want your material to be edited mercilessly or redistributed by others, do not submit it. (emphasis added)
In addition to the two technical sections that have been identified to merge to their articles, I think it would be good to move the list of frequencies to a seperate page. Any comments? Smiker 18:05, 22 October 2006 (UTC)
This section seems to have been written on the basis of a single user's experience and/or what he has read in advertising material for the DAB system. It is therefore a POV section rather than containing reliable and/or verifiable facts.
The author of the section fails to understand how OFDM works. In particular, OFDM can not eliminate the problems associated with multipath propagation, which seems to be the main thrust of the section. And DAB receivers do not go from a state of effectively perfect reception to muting in one small step - there is a relatively large transition, with receivers producing a "bubbling mud" sound in between what appears to be perfect reception and full muting. Some would describe this as DAB having a "shallow digital cliff". FM, on the other hand, "degrades gracefully", and it may or may not result in the signal being "swamped by noise" - situations that could lead to DAB reception failing may not give rise to FM reception failing, because DAB is wideband and FM is narrowband, therefore you could have a situation where opposite ends of a DAB channel's bandwidth (1.5 MHz between them) are in a deep fade, which leads to too many bit errors, which leads to reception failing, and this would obviously not be a problem with FM because of its much narrower bandwidth.
Furthermore, describing FM reception as being "swamped by noise" is negative language, and yet the section uses no negative language for DAB reception - just that it mutes, which it doesn't anyway.
The issue of SFNs (single-frequency networks) also gives rise to problems with DAB reception that would not happen on FM, because FM doesn't use SFNs. Reception with SFNs is problematic when signals travel farther than intended, possibly due to lift conditions, but also due to terrain.
Mobile digital communications is a complex subject, and I would suggest that only those that actually understand the technology should write sections about it, and someone simply repeating what they have read in material provided by organisations seeking to promote this technology has no place on Wikipedia.
You wrote the whole section from your own experience, and you tried to explain why the claims about reception were correct. Merely adding the word "claimed" to the section title does not justify copying claims made in adverts onto Wikipedia.
Back home I have a bunch of back editions of the WRTH. One of them (I think it was the 2002 edition) lists in detail DAB, DRM, and WorldSpace. I'm planning on coming from university for the Christmas break anyway. If I can manage to bring it back to uni, I'll probably look through the WRTH section and fix the article accordingly. Would this work? - Daniel Blanchette 20:28, 29 November 2006 (UTC)
I hope folks like what I've done. Added a criticisms of DAB section - that was a major omission. POV requires both angles to be covered, so if there is a benefits section, logically a criticisms section must also exist. If I can add an opinion to the discussion page, DAB was a good idea, but using a codec such as MP2, which is well known for being poor at low bitrates, as DAB has been used in practice by broadcasters, was a simply disastrous decision. I'm delighted DAB are finally starting to admit their choice of codec was wrong, and are adopting AAC+. But why oh why did they spend several years trying to force a 'worse than FM' standard on us all? Thank goodness consumers voted with their feet, and refused to accept this rubbish. One of the biggest consumer standard fiascos I can recall, that has severely damaged the credibility of radio, in the eyes of the IPOD generation. Timharwoodx 13:31, 2 December 2006 (UTC)
Couldn't agree more. Digitalradiotech 23:41, 7 December 2006 (UTC)
Regarding the introduction text: "The original objectives of converting to digital systems were to enable higher fidelity, more stations, less inteference, mobile services and additional information such as text, although in practice the vast majority of radio stations on DAB sound worse than on [[FM]."
This does not sound like a balanced encyclopedic text, and only has a UK perspective (and perhaps only Eureka perspective). Many other countries, for example the Scandinavian countries, has offered 192 kbit/s and higher, which should be clearly better than FM. See [2] for a list of countries.
Those who claim that this text should be kept, please give references that support for that the text is valid outside UK.
The main advantage with DAB was that it did not suffer from fading to mobile listeners. In many European countries, for example Sweden, the FM transmitters have quite low power and are quite sparsely deployed, resulting in fading when you drive car on the country side. You mention interference, but co-channel interference may still be an issue in DAB.
I therefor suggest the following formulation "The objectives of converting to digital systems were to enable higher fidelity, more stations, less fading to mobile users, mobile services and additional information such as text and EPG, although some argue that since several DAB radio stations in some countries have lowered their bitrates in order to make available more stations, DAB can sound less superior than FM."
In Sweden we have called DAB = dead and buried for a long time, but I don't think that was because of sound quality issues, but because it did not give any interesting extra channels, because of poor coverage, and expensive receivers.
The section about "Criticisms of DAB standard" is a great idea. However, that section is not very well written. Why not take the above formulation by Timharwoodx into that section?
Mange01 01:41, 8 December 2006 (UTC)
Recently, the description of OFDM that was present in this article was moved verbatim into the OFDM article; this completely disrupted the OFDM article. I've reverted the removed text; it can be found on the talk page for OFDM. Oli Filth 21:31, 3 December 2006 (UTC)
The first sentence should say what the article is about. Given that the term 'digital audio broadcasting' has two meanings, this has to be said in the first sentence. The problems that this dual purpose causes perhaps should be solved by splitting the article into two: one called DAB (Eureka 147) and another called something like Digital audio standards. The urgency to point out the shortcomings of DAB in the second sentence would then look less odd. JMcC 12:31, 14 December 2006 (UTC)
I'm happy with the new Introduction written by JMcC, thanks for doing that. There's a couple of typos, but the content is correct, which is the important thing, and it is definitely right for the page to be about DAB rather than Dab, so thanks for doing that as well. Just one thing though, the URL still says Dab rather than DAB, so I think it would be a good idea to create a new DAB page and have the Dab page redirects to the new page.
I'll go through the Claimed Benefits with you when I've got a bit more time. Digitalradiotech 13:40, 18 December 2006 (UTC)
I agree with the current version of the sentence, which has not been written by myself, but my Mange01:
"The original objectives of converting to digital systems were to enable higher fidelity, more stations and more immunity to multipath than in analog FM radio. However the bitrate of 224 kbps [1] that is necessary to achieve adequate quality in MP2 is rarely used, and so in practice the vast majority of radio stations on DAB sound worse than on FM[2] for stationary reception."
I suggest we leave it there.
There is a temptation to put too much in the intro. The new third paragraph beginning "DAB is operated in Band III.." is fine except it should be in the main body. The intro just has to tell people the main gist of the article. Putting this much detail too early does not make for easy reading. Since there seems to have been agreement on my moving out of the non-DAB stuff, adding 224 kbps and some other improvements, I hope I will be trusted on this one as well. JMcC 19:29, 18 December 2006 (UTC)
I beg your pardon about adding 224 kbps - I thought it was Mange01.
I would obviously be against moving the audio quality issue out of the introduction.
Personally, I think the long introduction is good, because much of the rest of the page is, well, poor. Over half of the page is about country-specific implementations, and a lot of the content is out-of-date or hardly relevant. The UK, Denmark, Norway, Switzerland and Germany (in that order) are the only countries you ever really see mentioned on the Wohnort site - ironically, the first article on there is about Canada, but DAB is almost dead in Canada now that they've got 2 satellite digital radio systems operating. The rest of the world is basically uninterested, despite what some would have you believe.
People have said "DAB has been introduced in ..." Well, it depends what they mean by "introduced". For example, DAB was "introduced" in Sweden in about 1995, but in total I believe less than 1000 receivers have been sold! I don't call that introduced, I call that wasting electricity. And this applies to lots of countries - there's basically no interest other than the 5 mentioned above, and out of those, it's only actually selling in reasonable quantities (relative to population) in the UK and Denmark - it's apparently impossible to find a DAB receiver in the shops in Germany.
So I'd suggest that the introduction stays as it is, and the country-specific stuff is condensed, discarded or moved. Digitalradiotech 02:00, 19 December 2006 (UTC)
The original objectives of converting to digital transmission were to enable higher fidelity, more stations and more resistance to noise, co-channel interference and multipath than in analog FM radio. However, the bitrate of 224 kbps [1] per audio programme that is necessary to achieve a non annoying near CD music fidelity in the MP2 audio codec is rarely used, and so in practice the vast majority of radio stations on DAB sound worse than CD players. In fact, in some countries less than 160 kbit/s is used, resulting in worse musical fidelity than FM [2] for stationary reception. For mobile non-line-of-sight reception at far distance from the transmitter, for instance at highways in hilly terrain terrain, FM suffers from fading caused by multipath, and may sound much worse than DAB. On the other hand, DAB still has very poor coverage in rural areas in most countries, meaning that this advantage seldom can be exploited.
Mange01 00:03, 21 December 2006 (UTC)
First of all: sign up with Wikipedia, because you're anonymous at the moment. Secondly, this is not an advertisement for DAB, this is an encyclopedia, and "innovate" can only be used when something new has happened, but DAB has been transmitting since the mid 1990s, so it is one of the oldest wireless digital systems around, so no way on this earth can you use the word "innovate". Thirdly, your comment about "FM can sound pretty shitty" is a RECEPTION issue, but people get bad reception on BOTH DAB and FM, so you cannot use this. There are already caveats about FM's failings, and I've not objected to keeping them in.
At the end of the day, there is no getting away from the FACT that the broadcasters are letting radio listeners down by broadcasting sub-standard audio quality. Which begs the question: why on earth are you sticking up for them? Surely you want better quality too? All you are doing is trying to HIDE FACTS from anybody that wants to be INFORMED. If you think that 128 kbps MP2 or 160 kbps MP2 is anywhere near FM-quality then you are, I'm afraid, completely wrong.
If DAB was as good as you are trying to suggest it is, then it wouldn't have been upgraded to incorporate the AAC+ audio codec. It really can be boiled down to that. The old version of DAB is a poorly designed system which should have been upgraded in the 1990s, but wasn't. It is also on its way out now that DAB has been upgraded, so the sooner you realise this then the sooner we can both stop wasting our time arguing about a few words on a page on Wikipedia.
Now, I suggest we discuss the issue here so that we can come to some agreement on the wording, rather than playing ping-pong with the introduction. Digitalradiotech 16:32, 21 December 2006 (UTC)
And I'll add something further: if you are not able to justify what you've written on this dicussion page, then you simply should not write it in the first place. Your removal of the 99% figure is no different from a lie, because it is a verifiable fact with a reference provided. So either leave that 99% figure alone, or justify why you have changed it. The word "most" is inappropriate to describe a situation where the percentage is 99%. Digitalradiotech 19:43, 21 December 2006 (UTC)
I strongly believe that both benefits and criticism deserves a link in the intro. This is en encyclopdia, and should include an easy way to get the full insight in both pros and cons of the subject. If not a link to the benefits are to be displayed in the same sentence as the criticism, I suggest that everything from the second sentence and out should be removed from the intro. Right now i re intorduce the link, and then the users can voice the view here...(Regards, Segrov, 25th of december 2006)
To Sergov: apologies for removing your section on variable bandwidth - I reverted the Norwegian ranter's additions at the same time as you had added the section (see the times in the History), so your section got removed at the same time. I'll put the sub-section back in.
This article may as well be written by the guy from www.digitalradiotech.co.uk and is completly laughable. DAB, like all mass consumer technologies, is aimed at the mass market not a small minorety of Hi-Fi buffs. I agree with your removal of the constant bias of this article and hope you'll delete more of it.
I have added metainforamtion as a benefit of dab, because even though RDS in theory offers this is a feature, i still havent seen it implemented anywhere in Europe; to my knowledge neither Denmark, Sweden, Norway, Germany, The Netherlands, Belgium or Spain has these features in action, but the same countries offers this in their DAB implemetations. Also, most RDS iplementations i have experienced only offer the name of the station, not the name of the program name, the name of the artist, epg and similiar content. (Written by Segrov on the 25th of dec, 2006)
Shouldn't that belong in the L-band article? - Daniel Blanchette 20:53, 16 February 2007 (UTC)
I'm moving this text here from Talk:Dab. -- Geniac 08:02, 18 February 2007 (UTC)
DAB stands for Digital Audio Broadcasting. DAB is a digital radio system, which was developed by the Eureka 147 Project. It offers near CD-quality sound, more stations, additional radio and data services and therefore wider choice of programs, the ease of tuning and interference-free reception for the listener, plus the information potential of data, graphics and text. For the broadcaster, DAB provides a means of reaching listeners with sound quality on an equal footing with the CD player, and the ability to offer extra, potentially revenue-creating, services. Transmission will also be cheaper.
Over 475 million people around the world can now receive over 1,000 different DAB services. Commercial DAB receivers have been on the market since summer 1998. There over 250 different DAB receivers commercially available (as of August 2006) and the numbers continue to rise.
So whats Wrong With FM and AM?
We live in a digital world. Just about every communication process we engage in, from making a phone call to booking an airline ticket . FM was invented in the 1940s, AM in the 1920s. So radio is using a delidigital age. Furthermore DAB Digital Radio has many advantages and benefits for all concerned.very system that is anything up to 70 years old. DAB therefore is taking the oldest of broadcast media into the digital age.
Furthermore DAB Digital Radio has many advantages and benefits for all concerned.Digital Audio Broadcasting provides crystal clear sound that is comparable to near CD quality - you can hear music as though you're in a first class concert hall, or listen to a discussion programme as though you're right in the studio. Remember what vinyl LPs sounded like compared to CDs? That's the difference between analogue radio (like AM and FM) and DAB. DAB is almost immune to the sort of interference that can make listening to today's conventional AM or FM radio less than satisfying. If you listen to FM in the car, you may have noticed hisses and plops as you drive along. That's caused by multipath interference when the FM signal bounces off buildings, trees and hills and arrives at your receiver out of phase with the main signal, confusing the transmission. But DAB is revolutionary because inside the receiver is a computer which sorts through the myriad multipath signals and other distortions to enhance the main signal. This means that even in the most difficult listening environments-like the centre of a city with high-rise apartment and office blocks-the DAB signal remains absolutely perfect. DAB receivers are intelligent and smart. —Preceding unsigned comment added by Tom129 ( talk • contribs) 12:47, February 15, 2007
That reads like an advert to me. -
Daniel Blanchette
20:57, 20 February 2007 (UTC)
Hi, The unregistered user from IP 82.20.7.186 has reverted good faith edits. I tried to improve the flow of the text by converting bulletted sections into paragraphs. I am guessing that the IP 82.20.7.186 user may have penned these sections originally. User IP 82.20.7.186, Wikipedia editors are only supposed to use reverting for vandalism. When you submit text, it is on the understanding that other editors will trim it, copyedit it, modify it. If you want to have your text sit unedited on a webpage, get your own web page. This is a communal project. One person submits content, others re-draft it, trim it, add to it. I made "good faith" edits to improve the content. Much of the content was kept, because my edits were mostly about form and writing style, not content. Please consider registering IP 82.20.7.186, because it helps other users to chat with you. As well, it helps other users to assess an editor's credibility. When you edit as an anon user, we have no way of knowing if you are an experienced editor, or a person who has just made their first Wiki edit. Nazamo 17:02, 26 February 2007 (UTC)
There is far too much pointless reversion bouncing back and forward. If this doesn't stop, people are going to end up being reported for Three-revert rule. Please stop it; it doesn't help anyone. If there are differences of opinion on the article content, then discuss them here, rather than continually reverting back and forth.
It seems that the prime offenders currently are Digitalradiotech and 195.159.3.166.
Oli Filth 13:16, 7 March 2007 (UTC)
Here's the comparison between the two edits: [6], and I'll go through what is wrong with the points he makes below.
"Digital transmission techniques were developed because digital transmission has the potential to provide a higher fidelity,"We're not talking about "digital transmission techniques", that is a general area, we're talking *specifically* about DAB and why it was developed. It was developed to provide higher audio quality. It does not in reality provide higher quality.
"Unlike with FM, there is no hiss with a weak signal on a DAB signal." That implies that DAB is perfect with weak signals, which is nonsensical rubbish. DAB, like ALL wireless communication systems, displays problems when the signal is weak - this is by definition, because otherwise the signal wouldn't be described as being weak.
"However, most of the stereo stations in the leading countries using DAB (UK, Denmark, Norway and Switzerland) use a bit rate below 192 kbps MP2, which means that these stations sometimes can sound worse than FM for stationary reception of music on high-end HI-FI equipment". That is simply a massive, massive, massive misrepresentation of the truth. Firstly, I have provided references that showed that literally NINETY-NINE PERCENT of stereo radio stations on DAB in the countries mentioned use bit rates below 192 kbps, and yet User 195.159.3.166 changes this to "most". He also adds the caveat "on high-end HI-FI equipment" to try and suggest that FM only sounds better than DAB on very expensive equipment. Well, I write DAB/FM tuner and portable radio product reviews for a hi-fi magazine, and I can assure you that you can hear that DAB sounds worse than FM even on portable radios, which are the least capable radio devices in terms of their ability to reproduce high-fidelity, so if you can hear the difference on these then you can obviously hear the difference far more on all more capable devices. Basically, his caveat is nonsense.
"With mobile reception like a car stereo, DAB is usually better than FM, because FM stations' sound has problems caused by multipath interference, noise and co-channel interference." DAB is not "usually better than FM" in cars, and the sentence provided in the edit I prefer is correct: "With mobile reception, FM can suffer from fading caused by multipath, and can sound worse than DAB." Firstly, DAB sounds worse than FM on car stereos whenever there's no problems with FM reception, and the only time I notice any problems with FM reception in my car is when I'm travelling down the motorway at 70mph+.
stationary receivers, and DAB which is best in a car." [4] 195.159.3.166 16:45, 9 March 2007 (UTC)
"This means there are effectively now three different versions of the DAB system: the older one, developed in the late 1980s, and an upgraded version, which has been named "DAB+", as well as DABs multimedia sibling DMB". DMB is not a version of DAB (Digital AUDIO Broadcasting). DMB was designed for mobile TV use.
"Existing DAB receivers are incompatible with the new DAB standard unless they are upgradeable". Actually that can be changed now, because there is ONE DAB receiver that's just come out (the Morphy Richards 27024 DAB/DRM radio) that can be upgraded, but all the others cannot.
"Established DAB-countries like UK, Denmark, Norway etc have no plans in abandoning the established DAB standard." That's making an assertion about future events, and Switzerland is one of the "established DAB countries" and it has already advertised station slots using DAB+. Basically, if this sentences stays then it needs editing to be balanced. Digitalradiotech 11:08, 9 March 2007 (UTC)
I'd like to present the views of someone who hasn't been involved in this debate, and hopefully bring some further objectivity and neutrality to this. To state my credentials (as they seem to be important to some people here), I'm not an expert on DAB, although I have an MEng and do wireless comms DSP for a living, and have edited a wide variety of comms/DSP/maths Wikipedia articles. Here are my comments:
I hope this helps. I also hope that those involved in the current edit war would add their responses to my thoughts before engaging in yet more to-ing and fro-ing between the same two versions of the introduction. Oli Filth 01:18, 13 March 2007 (UTC)
I'm starting all these indentations again from zero, because all of the above has become too messy.
Right, Ga-David raises 2 issues: my "credibility" and what Professor Holm says. Firstly my "credibility". In terms of education, I have a 1st class MEng degree (that stands for master of engineering), an MSc in digital comms and DSP (subjects directly relevant to digital radio technology) and another 1st class undergraduate degree from the Open University that consisted of engineering and computer science subjects. Next, I write for a hi-fi magazine primarily about DAB, and I also write DAB/FM receiver reviews for the same magazine. And I've been "commentating" on DAB on my website since I set it up in March 2002, and my website has been calling for the use of digital radio systems that use the AAC+ audio codec and Reed-Solomon error correction coding for around 3-4 years -- WorldDMB has in the last few months finally announced the new DAB+ standard where DAB has adopted the AAC+ audio codec and RS error correction, i.e. precisely what I recommended 3-4 years ago. Oh, and my website popularised the name "DAB+" about a year ago, and lo and behold that's what they've called it.
I've been interviewed for articles in the Guardian (twice) and the Daily Telegraph, and my website has been mentioned by the Sunday Times. I've written articles about DAB for 2 of the leading Norwegian national newspapers -- one article was published a couple of weeks ago. I've been contacted via my website by people from the City asking for advice, as well as numerous broadcasters from around the world and people working on digital broadcasting, not to mention several hundred individuals saying how much they liked my website -- about 1200 or 1300 people have joined my newsletter. On a debate about DAB on a Radio 4 programme the person that was complaining about the audio quality on DAB quoted my website verbatim, and the French radio broadcasters also quoted my website pretty much verbatim in their responses to a consultation about digital radio -- which is pretty much the event that led to DAB+ being designed.
The only people that question my credibility are the DAB broadcasters. What an amazing coincidence that is. And I've also asked Ga-David more than once if he works in the Norwegian DAB industry, and he's ducked the question each time. So I'll ask again: Do you work in the Norwegian DAB industry? If you do work in the Norwegian DAB industry then I'm sorry but your industry is well-known for being dishonest, and if you don't work in the Norwegian DAB industry and you're just an ordinary listener that owns a DAB radio, then I suggest you learn some respect for people that understand this far better than you do.
And Ga-David himself even admits "Digitalradiotech probably has a lot of knowledge in DAB", but of course he qualifies this with "but unfortunaltely i can’t trust his information".
The TRUTH here is that FM outclasses DAB in terms of audio quality. I've reviewed virtually all of the DAB/FM tuners that are available in the UK, and the radio station I use to gauge how good or bad the tuner sounds is Radio 3, because that is the highest audio quality source on both DAB and FM. Radio 3 is the ONLY radio station on DAB in the UK that uses 192 kbps, and Radio 3 is the BBC's 'flagship' radio station in terms of audio quality. And the simple fact is that Radio 3 sounds significantly better on FM than on DAB.
Comparing technologies it should really be obvious that FM sounds better anyway. FM isn't all-analogue as most people seem to think it is. The signal that is distributed to the FM transmitters is digital: in the case of the BBC they use NICAM (724 kbps, IIRC), and the commercial radio stations use APT-X at 384 kbps or 256 kbps. So in reality, if you have good reception quality on both DAB and FM -- which is the only fair way to compare -- then you're really comparing MP2 at whatever bit rate the station uses with NICAM or APT-X at far higher bit rates. It's no wonder FM sounds miles better.
What's happening on here is simply people trying to hide the truth using technicalities. Digitalradiotech 16:34, 16 March 2007 (UTC)
This article is constanly being reverted by DigitalRadioTech who quikly removes all edits that conflicts with his personal opinion. When ever someone edits text to be less biased towards a DigitalRadioTechs "DAB is BAD"-attitude, the edits are simply removed by DigitalRadioTech. He often operates under different ip-addresses as well, but i’m quite sure that most of these edits are made by the very same person.
I, GA-David (aka 195.159.3.166), am trying to keep other users constructive edits, so therefore you will se me in the log where i am trying to revert some of the vandalism from DigitalRadioTech - even though i have been threathened by the him. I know, it is not a good situation, but if anyone have a suggestion, please put a note on my talk-page. Ga-david.b 08:49, 30 March 2007 (UTC)
This is getting absurd, so I've reported both User:Digitalradiotech and User:Ga-david.b for 3RR; see WP:AN/3RR. It's nothing personal, but this is the easiest way to stop this stupidity. Oli Filth 18:53, 30 March 2007 (UTC)
This article is about a specific technology. While it is unfortunate that the developers of that technology have chosen to hijack a pre-existing generic term for their specific system, the terms can at least be distinguished by capitalization. Digital audio broadcasting ought to redirect to digital radio and not to this article. 121a0012 20:07, 14 July 2007 (UTC)
Someone is over and over again destroying this article by removing correct technical facts and introducing biased formulations that never would be accepted even in a high school essay. For example "DAB+ will replace DAB in all countries that use DAB". Of course we can not know that for sure.
I once started to work on this article, but someone removed perfectly correct technical facts that I wrote, for example that DAB is based on statistical multiplexing, and the main principles of the transmission. So I gave up. And now I found that the article still is poor.
So please everyone, try to use a more objective language.
Some suggestions for improvements:
Mange01 08:45, 16 July 2007 (UTC)
I just re read the intro. It is completely comprised criticism of DAB - how in the world can anyone pass this off as an unbiased, relevant and appropriate introduction?
"The original objectives of converting to digital transmission were to enable higher fidelity, more stations and more resistance to noise, co-channel interference and multipath than in analogue FM radio. However, in the UK, Denmark, Norway and Switzerland, which are the leading countries with regard to implementing DAB, the vast majority of stereo radio stations on DAB have a lower sound-quality than FM[1][2] due to the bit rate levels used on DAB being too low[3][4]. This assumes that the listener has good reception on both DAB and FM, however, but FM can suffer from fading caused by multipath when the receiver is travelling at high speed which DAB is less prone to. For stationary reception, FM can suffer from hiss when the signal is weak, whereas DAB produces a "bubbling mud" sound when the received signal is too weak for proper decoding."
I suggest deleting this whole paragraph and rewriting the introduction. Please can others comment on this, thanks. Chrisp7 10:11, 25 August 2007 (UTC)
The lead is very poorly written. My recommendation for a new lead: "Digital Audio Broadcasting (DAB) is a technical standard for radio broadcasting technology which is used by stations in several nations, particularly in Europe. The technology requires new equipment to be used by both broadcasters and listeners. As of 2006, approximately 1,000 stations worldwide broadcast in the DAB format, covering a total potential listening audience of 500 million people.
Proponents claim the standard offers several benefits over analog FM radio: better sound quality, more stations in the same broadcast spectrum, and increased resistance to noise. In practice, critics claim, broadcasters' choice to use low bit rate options of the standard have meant that listeners actually get worse sound quality than with FM.
Additional technical standards, said to be more robust, are currently under development under the term DAB+. Although DAB+ re-uses the DAB acronym, existing generation DAB receivers will not be able to receive DAB+ broadcasts."
The remainder of the article also needs significant editorial review, and more inline citations. The History section should remove references to specific technologies such as MP2 and OFDM.
If there is a Wikipedia article about "format wars," this would be an appropriate example and cross-reference.
VisitorTalk 15:51, 25 August 2007 (UTC)
Support' VisitorTalk's version of lead - I cannot speak for accuracy, but it's a far more encyclopedic lead than what I'm currently seeing. There is no way round the new version being "advertising" of the format and it's wrong to put criticism of it in there (unless it's imminent danger of being wound up because it's widely agreed to be terrible!). PalestineRemembered 12:30, 11 September 2007 (UTC)
Digitalradiotech,
I'm sure you are aware that adding "those 94% of people are wrong" is completely inappropriate POV and original synthesis. If you aren't prepared to edit constructively, then please stop editing.
As for the links, yes, we're all aware they exist, and they're all already in the article at least once. The "sound quality" section already exists under "criticism", there's no need to repeat yourself.
Oli Filth( talk) 00:58, 13 November 2007 (UTC)
As for the latest edit comments, you know full well that you cannot meaningfully state that people's subjective opinions are "wrong". At any rate, this is original synthesis, as I've already pointed out umpteen times. Oli Filth( talk) 01:59, 13 November 2007 (UTC)
In complete contrast to this, however, a different poll about what people would like DAB to offer in future found that 92% of people would like DAB to provide higher audio quality than it does at present( http://www.digitalradiotech.co.uk/future_radio_poll.php ). This suggests that those who are content with the audio quality on DAB are unaware that they are being provided with audio quality that is worse than FM.
I've added a {{ splitsection}} tag to the Regional implementations of DAB section of the article. The article is currently 52kB in size, which is a little on the large size. The majority of this is contributed by the section in question, which in my mind, seems an ideal candidate for a standalone article. This would leave this article to be a discussion on the history/technical details/pros+cons of the DAB standard itself. Thoughts, anyone? Oli Filth( talk) 00:46, 15 November 2007 (UTC)
I disagree that in-depth info about DAB+ is "most important"; it's a standard that was only published this year, and isn't (AFAIK) yet being used anywhere, so undue weight considerations would apply here. By the "number of interested readers" argument, most would be interested in the existing system, for which the pros/cons/raison d'etre info is relevant (and normally expected in an article lead). Of course, these considerations may change in time, as interest, etc. in DAB+ grows. Therefore, I've rearranged the order, and attempted to incorporate the new additions as best I can, whilst also attempting to improve the readability.
As previously discussed several times, self-citing to this extent is frowned upon in Wikipedia, so please can we find some more independent sources to replace these links (Digitalradiotech, as you wrote the pages being linked to, presumably you know where this info originally came from and can provide suitable links or references).
I've removed the addition to the UK section, because as it stands, this interpretation is original synthesis. If "The reason why this happened is that DAB is a spectrally inefficient system, and because the broadcasters chose to squeeze too many stations onto the DAB multiplexes." can be independently sourced, then it can go back in. Oli Filth( talk) 19:39, 16 November 2007 (UTC)
DAB comes in several versions; the more common DAB, as well as the newly established DAB+, or the multimedia oriented DMB and DAB-IP.
As requested:
From a Wikipedia/article perspective, use of the word "arguably" with no source cited can only be construed as POV, I'm afraid (see also WP:AWW).
As far as the topic is concerned, as I've already suggested, it could also be argued that other system choices are equally critical for the performance of DAB. As far as spectral efficiency is concerned, the choice between code rates of 1/3 to 1/2 (for example) has as great an effect as the choice between codec rates of 128 to 192 kbit/s. Equally, differing choices of modulation scheme and pulse-shaping have significant effects on the spectral usage. The choice of interleaving depth is critical for the system's ability to cope with fast fading (i.e. the difference between it being usable in vehicles or not). The particular combination of all parameters directly affects system complexity, and therefore receiver power-consumption and cost, which are critical in a consumer application such as this. I'm sure you're aware of all this already, though. Oli Filth( talk) 14:51, 17 November 2007 (UTC)
Is is, deal with it, and you're showing your bias towards an area that you have a personal interest in by putting transmission above FEC coding. The things that matter to radio listeners are the content/stations, audio quality and reception quality, and FEC coding is the main determinant of reception quality, so stop trying to think you know better than me about digital radio technologies and their relative importance, because you don't.
The Error-correction coding section currently mentions that DAB+ uses Forney interleaving. However, the spec (ETSI TS 102 563) makes no mention of this; instead, all it describes is how the RS is performed on interleaved data, and that the data itself is forwarded in original order. On the other hand, the DMB spec (ETSI TS 102 427) does explicitly mention the use of Forney interleaving.
Does the article section need correcting? Oli Filth( talk) 14:06, 18 November 2007 (UTC)
Quoting from Computer Networks by Tanenbaum, section 1.4.1 "The OSI Reference Model":
"The physical layer is concerned with transmitting raw bits over a communication channel."
"The main task of the data link layer is to take a raw transmission facility and transform it into a line that appears free of undetected transmission errors to the network layer."
Basically, if you want to say it's in the phy then you have to remove the reference to the OSI stack, or you keep the reference to the OSI stack and put it in the data link layer. I'm easy, but as it stands it's incorrect. I'm going to undo your edit, but if you want to lump everything together as being in the phy then fine, so long as you delete the reference to the OSI model and the mention of the audio codec being in the application layer.
DigitalRadioTech, Here is the current paragraph in the intro:
DAB exists in several versions; the more established DAB, as well as the recent major revision DAB+ from 2006, and the video oriented DMB and DAB-IP wich is used for handheld tv broadcasts.
Will you be more happy with this? My concern is that the paragraph about DAB+ intro should be brief, and the we should go in depth on DAB+ in the apropriate section.
DAB exists in several versions; the more established DAB, as well as the recent major revision DAB+ from 2006, being approximately three times more efficient than DAB, but wich is not backward-compatible with the original standard. Several countries are expected to launch DAB+ broadcasts over the next few years. Also there is video oriented DAB versions DMB and DAB-IP wich is used for handheld tv broadcasts.
I believe Ga-david.b has edited from 195.159.3.166, at least from my reading of the 195.159.3.166 talk page [18].
Interestingly, 195.159.3.166 edited the Norwegian DAB article on 14 Nov 2006 [19] to include this sentence: "Men MP2-formatets fordel er at det har en større toleranse for feil bitfeil en mer kompakte om moderne formater som ACC+ og WMA, og dermed vil MP2 være bedre egnet for den norske topografien.". Roughly translated, this says "But the MP2-format advantage is that it has a greater tolerance for errors bit-errors than more compressed modern formats like ACC+ and WMA, and therefore MP2 will be better suited for the Norwegian topography". The current article has made some modifications to this sentence so it now appears as "Men samtidig har MP2-formatet også fordeler. F.eks. har det større toleranse for feil enn mer kompakte og moderne formater som ACC+ og WMA, og dermed vil MP2 være bedre egnet for den norske topografien hvor skog og fjell vil kunne gi ørsmå forstyrrelser.", which is roughly "But at the same time, MP2 format also has advantages, for example, it has greater tolerance for errors than more compressed and modern formats like ACC+ and WMA, and therefor MP2 is better suited to the Norwegian topography where forests and mountains will likely give greater problems (not sure how to translate "vil kunne gi ørsmå forstyrrelser")"
My understanding is that this is factually misleading (it is also uncited in the Norwegian Wikipedia), and that DAB+ using ACC+ actually has a greater tolerance of bit-errors than MP2 due to the additional use of Reed-Solomon encoding in DAB+.
The pdf here http://www.worlddab.org/upload/uploaddocs/WorldDMBPress%20Release_November.pdf gives an overview of the use of Reed-Solomon and AAC+.
Why this somewhat long screed? Well, I think Ga-david.b may be inadvertently incorrect in his/her knowledge of DAB and DAB+ and making good faith edits that are on the basis of incorrect knowledge/understanding of the subject matter. If that is true and we can correct that, then I'm sure the English article will benefit from that, *and* the Norwegian article (which would benefit from some citations and some minor rewriting)
Cheers,
WLD talk| edits 18:32, 20 November 2007 (UTC)
This article still has an enormous negative slant - my attempt to improve one small part a few months back (the introduction) have largely been in vain. The article makes continual references to the sourec of 1 individual who is in effect 'in control' of this page. A group effort is required to remove its bias and non neutral languange and references. Chrisp7 ( talk) 13:47, 2 February 2008 (UTC)
98% of stereo stations in the UK, Denmark, Norway and Switzerland (which are the only countries where DAB sales have taken off)
Those statistics are HEAVILY weighted by the UK having far more DAB stations. It's not fair to average an overwhelmingly large value with other tiny ones. I recommend either rewording the statement to single out just the UK as using 128kbit/s for audio, or using the worldwide averages instead, where the average bitrate is higher. "Taken off" isn't a useful or NPOV measure anyhow.
are using bit rates levels that are too low.
"Too low" for what and according to who? This is vague and inherently POV. I would suggest just specifying the relevant bitrates directly to make the point. More detail can be explained in the article, rather than putting so much in the intro.
DAB+ is approximately three times more efficient than DAB
This is oversimplified to the point of inaccuracy. That 3x figure seems due to the poor performance of MP2 at very low bitrates compared to HE-AAC. On further reading (of trev_305-moser.pdf) the figure is more accurately about 2X when using higher, more reasonable bitrates (ie. 96-128kbps). eg. "The bandwidth reduction for aacPlus transmissions compared to competing systems exceeds a factor of 2".
The choice of audio codec is one of the most important aspects in the design of a digital radio system,
Poorly worded and POV. I could just as well say modulation or error correction is the most important...
a network of transmitters can provide coverage to a large area - up to the size of a country
Liechtenstein or Russia? Not a useful metric...
I hope someone will work on these problems with the article. It's pretty good otherwise. If not, I'll eventually get around to it myself. Also, this huge talk page would benefit from being setup for auto archiving. Rcooley ( talk) 19:37, 31 March 2008 (UTC)
We're not interested. Coming into our area and BLATANTLY VANDALIZING and erasing several paragraphs of information that has been carefully written & supported by external references is NOT acceptable behavior. ----- Focus on your own backyard, and stay out of ours. DO NOT ERASE WHOLE PARAGRAPHS WITHOUT FIRST DISCUSSING IT in the talk page for hd radio. That is poor etiquette. ---- Theaveng ( talk) 14:02, 29 April 2008 (UTC)
I've edited the intro and removed text that might be deemed advertorial. I've also addressed all of the issues RCooley mentions above. I've also removed the text about GCap withdrawing its support for DAB and moved that to the Regional implementations of DAB page and put it in the UK section. I've slimmed down the section on DAB+.
I feel that the intro is now okay. Digitalradiotech ( talk) 09:55, 30 April 2008 (UTC)
Loren.wilton ( talk) 13:23, 30 April 2008 (UTC)
So, what are the specifics of DAB+? Canada's deployment of DAB calls for five music programs per channel, and an unknown (to me) number of non-music programs. The channels are 1.744 MHz apart. What are the comparable traits of DAB+? GBC ( talk) 01:40, 30 July 2008 (UTC)
Does it have copy protection? Towel401 ( talk) 00:47, 19 August 2008 (UTC)
Could somebody explain why, if DAB+ is far superior (as this article says), would RTÉ begin its DAB service this morning, 1 December 2008- http://blogs.rnw.nl/medianetwork/rte-to-launch-five-national-digital-radio-services- rather than a DAB+ service? I accept that RTÉ began its trial versions of DAB in January 2006, i.e. before DAB+ was released in February 2007. However, if the differences are so significant between both systems, why would they have not changed to the newer version by now, December 2008? Basically, I want to but a DAB type radio with Ipod dock, and I'm wondering which is the best system to buy now given the above. Thanks. 192.122.218.190 ( talk) 22:53, 1 December 2008 (UTC)
Does anybody know where one can find slimline DAB systems that have an IPOD dock? They all seem to be unnecessarily bulky- like something from the 1960s. What is the sense in such bulky designs in 2008? 78.16.192.72 ( talk) 23:28, 3 December 2008 (UTC)
"Hungary is due to launch DAB+ stations in 2008..."
This sentence is now iytdated. 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) 22:13, 15 February 2009 (UTC)
Is this article unbiased and balanced? Several people have over some time (a year or so) been complaining about a persons continous lack of will to change the introduction, as you might see from both the history as well as the talk-pages.
Yes. I certainly think so. Please fix. The opening is terrible. 124.157.251.100 ( talk) 09:22, 14 June 2009 (UTC)
Info (19 February 2009)
Info (19 March 2009)
Info (09 April 2009) —Preceding
unsigned comment added by
Kingdavid007 (
talk •
contribs)
14:28, 13 May 2009 (UTC)
The Intro starts by slamming DAB sound quality on a quite theoretical point of view.
Also, one of the main sources is http://www.digitalradiotech.co.uk/dab/worldwide_dab.htm but this site is somehow not thrustworthy. Have a look at the front page: http://www.digitalradiotech.co.uk/
Also, one of the other sources, the Norwegian doctor Sverre Holm ( http://www.duo.uio.no/sok/work.html?WORKID=52348), claims that the FM is comparable with 160kbits DAB transmissions, while the last source - David Robinson – is not available online, and also seems to have some sort of connection with the biased source
I have now removed the biased source, and adjusted the introduction a little to reflect the only reliable source, the Norwegian Sverre Holm. —Preceding unsigned comment added by 84.48.121.36 ( talk) 11:34, 16 November 2009 (UTC)
The Sound Quality section contains the following odd statement:
The UK government doesn't decide on transmission bitrates. This is largely decided by the BBC and OFCOM, neither of which are part of the government. The audio bitrate on digital TV channels varies (many use 128k), but it takes up a very small part of the total TV signal bitrate anyway and the subject is nothing to do with DAB.
I'm inclined to remove all this, as it contributes little to the article and is really just a confused grumble about low audio bitrates. Do others agree? -- Ef80 ( talk) 19:30, 3 December 2009 (UTC)