Talk:Digital Audio Broadcasting/Archive 1
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Archive 1 | Archive 2 |
Merged page
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)
DAB in the UK
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)
- This section of the article is definitely POV - and would appear to come from a specific commentator who is rabidly anti-DAB on Usenet.
- The criticisms are quite trivial in my opinion, and unless someone gives good citiations from other websites, I will actually remove the sections. Anon Dude 17:41, 24 July 2006 (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 (?!)
- The criticisms of DAB sound quality are frankly inaccurate - yes FM definitely sounds better on a decent stereo in a good reception area with external aerial. But that isn't the only way people listen to FM, small radios (such as bedside radios) that use a simple wire for reception often sound far superior on DAB than the a similar FM radio would. A better wording would be that "With good reception, it is always possible to get higher sound quality on FM stations than on DAB." It's also ignored that the national mono music stations aren't available nationally on FM, so the implication that that makes them worse quality on DAB than FM is absurd.129.67.21.202 03:15, 2 February 2007 (UTC)
- Excellent point! And I had my comment on FM reception needing to be optimum deleted by Digitalradiotech. I have restored my post but I am sure that as soon as he comes back online he will delete it. 159.134.128.202 20:12, 5 April 2007 (UTC)
- Yes, certainly an excellent point that ≈everyone can suscribe to. However, as 159.134.128.202 points out, one person (DigitalRadioTech) is constantly removing every piece of balanced information. This is not a good situation. I suggest you people keep up editing this article for the better. If DigitalRadioTech is contiuning the vandalism, we could ask the administrator to talk him right. For now i will once again remove the silly links to his own website. Ga-david.b 18:35, 30 April 2007 (UTC)
- Can I remind you of the Wikipedia:Assume good faith and Wikipedia:No personal attacks. Calling someone's links to a website 'silly' doesn't comply with these. They may possibly be misguided, or the source may be unreliable, but it is not appropriate to call them silly. WLDtalk|edits 07:18, 1 May 2007 (UTC)
- Of course you can remind me of good fait etc, but that doesnt help when the person who is creating all the trouble – DigitalRadioTech – is not participating in resolving the problem. I improved the article by pointiong to the original sources of the same information, only to see my effort ruined the very next day. I find that rather silly, and i can’t help slipping my thounge. Also bear in mind that me using the term "silly" is not what is causing all this wandalism here. Ga-david.b
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)
- I can provide verifiable references for all the flagged comments. I haven't got the time to add them now, but I'll try and add them tomorrow. The sources for the info will mainly be Ofcom documents, because they said that 90 stations won't be able to transmit on DAB, mainly because smaller stations can't afford it. Some of the comments may need to be revised, but I disagree that the section should be deleted. Digitalradiotech 19:28, 13 May 2007 (UTC)
- I agree - just delete the section. The user Digitalraditech has been allowed to keep this section here for far to long. Note that he is only refering to his own website, and not to a credible source. Ga-david.b 12:46, 18 May 2007 (UTC)
DAB2
could you please give some link about DAB2? --Pejman47 10:53, 10 October 2006 (UTC)
- There are a number of mentions of DAB2, DABv2 and DAB+. Googling for these doesnt pull up any references for these terms (other than some chat). I propose we remove these terms from the article? Smiker 20:33, 6 November 2006 (UTC)
Incorrect technical description of orthogonality
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.
POV
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)
- I have added the POV tags to identify that the article is not NPOV. I make no claims of doubt of the authenticity of the references, rather the relevance. In order to not revert war over the tags, I was keen to have an independent opinion, hence the {{pov-check}}. NPOV means that the article need make no judgements. e.g. genocide states what it is, not that genocide is considered to be bad, or reference surveys that state that 98% of people thought it was bad. I believe those references can still be cited but in a neutral way. Smiker 12:18, 8 November 2006 (UTC)
- I'll do a quick NPOV test on this article soon. However, I see a problem with "Criticisms of DAB in the UK". Since some of it is general in nature, shouldn't the general stuff be with the technical section? Also, there is a repeating sentence in the article. -Daniel Blanchette 21:01, 8 November 2006 (UTC)
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)
- Thanks for your response. Just to clarify a few things:
- My only reasons for reverting the POV tags were that I felt there was a POV issue, and it was being removed by anonymous editors without discussion on this page. I still feel these issues have not been resolved and hence the request for a neutral opinion rather than just revert warring.
- My original justification for POV tags was not references for facts, however some facts have needed sources which I am glad to see.
- If you want my opinion I do beleive that DAB quality in this country has been compromised by the low bit rates. However, this is an encyclodpeia so we need to present everything (including facts) neutrally.
- To take you concorde analogy, if the article stated "concorde is worse than a jumbo because the seats are smaller", you have a mixture of a fact and an opinion. Even if I could quote a citation that shows that 90% of people agreed, it unfairly pushes that POV. However, I can compare the seat sizes and leave the reader to make an opinion. So is there a way for DAB that we can quote the facts and leave the opinion to the reader?
- To look at this positively how can we create a good article? To quote on POV:
"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??
- Reply by JMcc.
My edit was nothing to do with censorship. My reasoning is:
- The Manual of Style states that: "Normally, the first paragraph summarizes the most important points of the article. It should clearly explain the subject so that the reader is prepared for the greater level of detail and the qualifications and nuances that follow. If further introductory material is needed before the first section, this can be covered in subsequent paragraphs."
- The article therefore has to explain what DAB is before digressing into the particular problems in a particular country. The article is about digital audio broadcasting not DAB in the UK. Putting a detail point about the UK is at variance with the MOS guidelines about the intro. After explaining the basics of what DAB is and how it differs from FM, only then is it possible to describe its claimed benefits. These also have to be general. However in this section it clearly states there is a trade off between the number of stations and the quality and specifically refers to the criticisms of the UK's implementation of it.
- I have no rights over and above any other user such as you. However we are all learning from each other. My reasoning about asking you not to reverse my edit is that you are a new user who has not yet registered, and so you probably do not yet fully understand about the structuring of articles and about keeping country specific comments in their place. I have only been editing on Wikipedia for about 18 months but I hope other more experienced users would back me up on this.
- You are quite right I do not understand OFDM and my congratulations to you if you do. I came across the article when it was a mess. It has now been restructured so that future edits can be made in an organised way. The claimed benefits have to be explained as well as the downsides. There is plenty of scope for you to do this in this section, but please do not mess up the intro.
- Your credibility would be greatly enhanced by registering as a user. You would then be able to sign your contributions by adding the four tildes at the end. JMcC 15:11, 14 November 2006 (UTC)
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.
- It is hard to communicate with someone whose ID keeps changing. Vandals, fanatics and new users tend to be anonymous, so many will view your contributions with suspicion, however worthy they might actually be.
- I have no problems with an argued objection to each claimed benefit, but the claimed benefits (even if false) have to be there to explain why anyone bothered with the technology, however misguided they may have been.
- The article is titled 'Digital audio broadcasting' not 'Digital Audio Broadcasting' and so Eureka DAB is just a sub-set, with the UK within that, even if it is a large sub-set.
- I do not disagree with anything else you say. This discussion started by you putting a claim about quality in the UK in the intro. It is not censorship; it is merely putting the information in a logical order. JMcC 16:45, 14 November 2006 (UTC)
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)
- Well, there's certainly a difference of opinion between editors on this article. A step towards resolution of this issue would be to ensure that all statements made are backed up by verifiable sources. One of the problems is that audio quality is pretty much subjective, and testing protocols to eliminate subjective bias are drawn out and expensive, so few are done. I don't think anyone disagrees that at a 'high enough' bitrate, MP2 will give better audio quality than FM, but (and it is a big but), actual listening conditions and actual interference, as well as the use of less than the maximum possible bitrates muddy the waters a great deal. I'm sympathetic to those who are not impressed with current UK DAB implementations. I have had to deal with voice codecs over a variety of bitrates and interference, and now that I am attuned to the distortions, I find most VoIP, mobile phone, and DECT implementations to be terrible - but in a commercial sense, they are 'good enough' - but unlike FM, where you can invest in a better antenna and a better amplifier, you can't improve much on the quality 'designed in' to the digital codecs chosen. It might be politic to propose changes here on the talk page, rather than editing the article so we can demonstrate consensus being reached, rather than change by fiat. WLDtalk|edits 09:23, 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)
- My understanding of Wikipedia policy is that the article should be a neutral presentation of the (verifiable) facts. In the case of DAB, my current opinion (with very little evidence to support it) is that there is sufficient discussion about the quality of DAB to merit a statement in the introduction saying something along the lines of "the acceptability of the audio quality of DAB is disputed by a significant number of people" - so long as that statement can be verified by a cite, preferably to an academic source, or failing that to a reputable non-academic source. A single person's differing opinion does not make it into a dispute meriting an encyclopaedic entry - industry discussion in technical publications, industry newsletters, and the general press probably does. The details of the debate, pro- and anti- points, and their respective rebuttals should be further on in the article, all supported by verifiable citations to high-quality sources. The article itself is not the place to conduct the debate, and neither is the talk page - Wikipedia is not the place for doing this, as the talk page is about the article, and how to improve it, not about the subject of the article (a fact often missed) - there are pleanty of other web-fora and usenet discussion groups for the debate itself, and Wikipedia is not one of those. Wikipedia reports that facts contained in verifiable (usually secondary) sources, and does not editorialise, or synthesise new opinions from existing facts. Sometime this means Wikipedia misses 'breaking' news/ideas, but this is no big deal in the scheme of things. Regars, WLDtalk|edits 14:39, 19 April 2007 (UTC)
- I'm not sure that the debate is about the quality of DAB, more as to whether the bitrates used in some territories are sufficient, which is kind of different. I did try and meet in the middle with my comment regards the criticisms regards low bitrates and the link to the criticisms section, but the edit was just reverted without comment. Your, "the acceptability ..." sentence would do just fine with some brushing to make it clear that it's an implementation issue that's teritory specific, but I suspect that any attempt by anyone to make changes along these lines will just be reverted. I really would like the DAB article to be complete and informative, and this includes the fact that there is criticism of it from some quarters, but currently it's all very out of kilter at the moment. We do have an interesting parallel with DVB-T. This is also replacing analogue TV in the UK, and bitrates at times are very low and are often criticised by sports fans. But the wikipedia DVB-T article doesn't kick straight into attacking DVB-T because of the old MPEG2 codec that it uses, nor hinting that it's obsolete is deployed in the UK now that H.264 is coming along. --Ian 15:29, 19 April 2007 (UTC)
- The Wikipedia:Ownership of articles policy comes into play here:
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)
It's also woth reading the essays (not policy) :Wikipedia:Tendentious editing and Wikipedia:Don't be a fanatic. There is room in the article for well-sourced information from reliable sources - any reader should be able to check that material added to Wikipedia has already been published by a reliable source (Quoted from the Wikipedia:Verifiability policy), so if such information is being deleted, it should not be (so long as it is relevant). - On another point, skewed language should be avoided, as it is not neutral. Also, weasel words and peacock terms have no place in the article (Wikipedia:Avoid weasel words, Wikipedia:Peacock terms).
- Having thrown a load of policy and guidelines into the mix, I'll step back - any edits Must (policy)/probably should(guidelines) conform with the above, and any editor can remove text that does not conform. Regards, WLDtalk|edits 16:17, 19 April 2007 (UTC)
- The Wikipedia:Ownership of articles policy comes into play here:
- I'm not sure that the debate is about the quality of DAB, more as to whether the bitrates used in some territories are sufficient, which is kind of different. I did try and meet in the middle with my comment regards the criticisms regards low bitrates and the link to the criticisms section, but the edit was just reverted without comment. Your, "the acceptability ..." sentence would do just fine with some brushing to make it clear that it's an implementation issue that's teritory specific, but I suspect that any attempt by anyone to make changes along these lines will just be reverted. I really would like the DAB article to be complete and informative, and this includes the fact that there is criticism of it from some quarters, but currently it's all very out of kilter at the moment. We do have an interesting parallel with DVB-T. This is also replacing analogue TV in the UK, and bitrates at times are very low and are often criticised by sports fans. But the wikipedia DVB-T article doesn't kick straight into attacking DVB-T because of the old MPEG2 codec that it uses, nor hinting that it's obsolete is deployed in the UK now that H.264 is coming along. --Ian 15:29, 19 April 2007 (UTC)
Spliting off sections
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)
- I agree that this information does not belong in the main article; it completely breaks the flow and looks ugly. However, I'm not sure it needs to exist on Wikipedia at all - it's not useful or interesting information; anyone who would be interested in all the exact frequencies can find the details from the ETSI standard, which is freely available.
- However, if a new article is created, I think that the values should be in tabular form, showing the grouping in the Band III frequencies. Oli Filth 18:42, 22 October 2006 (UTC)
Claimed Benefits
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.
- I would have thought it would be more acceptable even to you to have a section called 'Claimed benefits' because the very title shows these could be disputed. That these benefits are claimed is irrefutable. However to maintain a NPOV these claimed benefits have to listed and described, even if you later demolish each one in turn. JMcC 15:47, 14 November 2006 (UTC)
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.
Would a WRTH help?
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)
Tidy up
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)
Only UK perspective in the introduction text? Fading
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)
- In response to Mange01: Have you ever actually heard DAB in Sweden? I believe there were an *extremely* low number of DAB receivers sold in Sweden up to now, and now the government has scrapped plans to use DAB, so I would imagine you haven't heard it yet. However, I know a couple of audio engineers that work in the Swedish broadcasting industry, and I'm sure they could provide you with a brief explanation of precisely what they think of the audio quality on DAB - I know for certain that they will say it sounds worse than FM.
- I was worried that you were going to ask that. :) Well I have heard FM fading while driving on countryside roades. Have you? People say that is not a problem in the U.S., but I doubt it is only a problem in Sweden. I have also heard MPEG layer 2 192 kbps demo files on the Internet, which is . I don't find any good sample file right now on the net. The samples at [3] at your impressive site does not work. This article, or the MPEG-1 Audio Layer II article, should have a link to the samples. That should solve the dispute. FM and DAB with fading should also be illustrated with sample files. Mange01 15:47, 18 December 2006 (UTC)
- You also talk about the "advantages" of DAB for a country like Sweden, and yet fail to mention any disadvantages, such as that DAB is a ridiculously inefficient system which is ridiculously expensive to transmit, and for a country the size of Sweden, that would be a very, very bad thing indeed. For instance, the commercial radio stations wanted to use 128 kbps, no doubt because it is a lot cheaper to transmit at a lower bit rate.
- Please define efficient. It is frequency spectrum efficient compaired to FM. FM requires 0.3 MHz per programme. The frequency reuse factor is aproximataly 15, resulting in 1/15/0.3 MHz = 0.22 programmes per transmitter site and MHz. DAB with 192kbps codec requires 1.536 MHz * 192kbps / 1136 kbps = 0.26 MHz per channel. The frequency reuse factor for local programmes and multi-frequency broadcasting networks (MFS) is 4, resulting in 1/4/0.26 MHz = 0.96 programmes per transmitter site and MHz. 333% as efficient! For single frequency networks (SFN), for example of national programmes, the channel reuse factor is 1, resulting in 1/1/0.25 MHz = 3.85. 3.85. 17.3 times as efficient as FM!. However, I suppose that L-band frequencies are inefficient for hilly terrain, and for indoor communication. Do you mean that a higher number of transmitter sites or higher transmission power required in DAB for full coverage, because of the L band frequencies. Or do you only mean that digital equipment is more expensive for the moment? Mange01 15:47, 18 December 2006 (UTC)
- Furthermore, in your version of the introduction you suggest that one of the objectives of DAB was to design an EPG. The EPG was only designed recently, I'm afraid, and the original objectives were drawn up in the 1980s.
- Also, your suggestion that 192 kbps MP2 should "clearly be better than FM" is based on what, exactly? Here's the results of a probably the most quoted blind listening test, and 192 kbps MP2 was classified as being "Slightly annoying": Soulorder paper.
- The simple fact is that the vast majority of DAB stations sound worse than FM, and trying to change the introduction is simply providing misinformation seemingly based on nothing more than your own belief, and you probably haven't even heard DAB in your own country yet! Digitalradiotech 16:35, 12 December 2006 (UTC)
Merge into OFDM article
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)
- Good initiative! Mange01 21:37, 3 December 2006 (UTC)
- Well, why did no-one disagree with the merger proposal? The page was clearly tagged in advance of the move, yet no objection was raised.
- Firstly, no discussion was started explaining the pros of the merge. Secondly, I didn't realise it was going to be a verbatim dump of the content from the DAB page!!
- I'm not quite convinved it 'completely disrupted' the ODFM article, since it was inserted into an already existing section concerning DAB radio.
- Indeed, but the vast majority of the content that was inserted is already covered in the OFDM article, so it just introduced a lot of redundant material. Also, it would mean that the section on DAB would have gone into disproportionately more detail than the sections on DVB, etc.
- Anyone have any preferences for where the OFDM content goes? It may need a new page, then. Its just with DAB 2 rolling out, the DAB page is only going to get larger, and there really isn't the space for the ODFM content any longer. I assume we can all at least agree on that point. Timharwoodx 17:04, 4 December 2006 (UTC)
- Agreed. My view is that seeing as most of the info is already covered in the OFDM article, it doesn't really need to go anywhere. We just need the briefest of overviews on the DAB page (e.g. "DAB uses coded, DQPSK-modulated, OFDM...") and an appropriate link on the DAB page. Oli Filth 18:01, 4 December 2006 (UTC)
- Okay, so edit it down. I'm sure no-one has any issue with that. Timharwoodx 18:32, 8 December 2006 (UTC)
- I've re-read the stuff from the DAB article (currently sitting at Talk:Orthogonal_frequency-division_multiplexing#Removed_text, and there doesn't really seem to be anything to add to the OFDM article that isn't already covered. At some point I may insert a brief summary (as I suggested above) into the DAB article. Oli Filth 18:53, 8 December 2006 (UTC)
Intro
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 agree, because I think this page should be about DAB, not Dab - 95%+ of the content is about DAB already, probably nearly all of the people that edit the page are referring to DAB, and I'm not even convinced that "Digital audio broadcasting" deserves a page at all, because the broadcasting of audio is synonymous with radio, and there is already a Digital Radio page with links to the different systems. However, this is a debatable point. Also, as someone else has said on the discussion page, there seems little point in having content about the US on this page, as the US hasn't adopted DAB. Digitalradiotech 15:45, 15 December 2006 (UTC)
- Your wish is my command. Having done that, now please take me through step by step which statement in the claimed benefits that you disagree with and suggested how it could be re-phrased. JMcC 19:14, 15 December 2006 (UTC)
- To be honest, I think saying "Not to be confused with digital radio" makes it more misleading, because it makes the page more to do with Dab, and not less. The page is, as I've said, about 95%+ about DAB, and FM and all the other broadcasting systems will have their own page, so DAB should have a page of its own rather than it being combined into a single page together with the generic "Digital audio broadacsting". Digitalradiotech 20:26, 17 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.
- NO. I slightly revised someone elses formulation. I tried to be objective, but the Digitalradiotech seemes biased by some reason. Mange01 00:03, 21 December 2006 (UTC)
- I am definitely not biased. And I am not the one that is trying to mis-inform people here.
- If you’re serious about not mis-informing, then start adding relevant information at the appropriate place, and stop adding that "sound worse"-criticism in the intro. Yes, I know that’s your slogan on both your own webpage and on the usenet, but this is an encyclopdia article about DAB, and not a place to broadcast your own, subjective opinion. Beside, the same information is already present in the criticism section of the page. Comment added by Ga-david.b (talk) 28 December 2006 (UTC).
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)
- Reference number 1 does not compare with FM, but with CD. Have you read reference number 2? See [[4]]. It states that for similar quality as FM, at MP2 with least 160 kbit/s is required, and to almost guarantee that the quality is better, 192 kbit/s is required. I therefor changed the article to the following. It shold be shortened, but first of all we must agree on the facts.
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)
- David Robinson, who wrote reference 1, used FM samples that had poor reception quality. How do I know that? Because I know David Robinson, because if you read reference 1 you'll see that I co-authored the report that the article is about (I write the digitalradiotech.co.uk website).
- I asked you a question last time, and you don't seem to have answered it: have you EVER listened to DAB yourself? And from reading your personal page, you don't indicate that you have any interest in or knowledge of digital audio coding, so why do you now think you can lay down the law about digital audio coding all of a sudden? I'm sure you have an excellent knowledge of the subjects you know about, but I'm a firm believer in sticking to the subjects that you know about and let those that have a good understanding of other topics deal with them. Digitalradiotech 10:52, 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.
- Event if it’s a recption issue, it still is bad SOUND. If it’s broadcast quality you’re concerned about, then you should write about the broadcast quality, not about SOUND. You simply can’t know what kind of reception (and what kind of SOUND) people experience. Comment added by Ga-david.b (talk) 28 December 2006.
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.
- No i havent hidden anything - i’m simply moving facts to their appropriate place. Yes, sometimes people get better sound with FM, and sometimes (most often if you ask a norwegian) they don’t. Big deal? I think not. It’s not worth spending several lines in the precious introduction. Comment added by Ga-david.b (talk) 28 December 2006 (UTC).
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.
- ACC+ will allow more stations with the same quality, but there is no plans for ACC+ broadcasts in UK, denmark, norway. So whats your point? I’m simply improving the article. Comment added by Ga-david.b (talk) 28 December 2006 (UTC).
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)
- Another fact is that bit rates vary. For instance several norwegian stations share broadcast at nighttime. Have you accounted for that? And btw: using a page like digitalradiotech.co.uk as a reference doesnt really convince me; the page seems to be quite biased. Comment added by Ga-david.b (talk) 28 December 2006
Link to Benefits vs link to Criticism
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)
- Having "despite the benefits" straight after the list of original objectives suggests that all of the original benefits were fulfilled. The benefits and criticisms sections are linked to in the contents list, so I don't think it's absolutely necessary to have links to them in the intro and readers can easily find them if they want to. Furthermore, the link to the criticisms section coincidentally didn't even work... Digitalradiotech 12:33, 27 December 2006 (UTC)
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.
- Personally I think you are destroying the article and made it worse than before. An important aspect of Wikipedia is to let everyone contribute, but looking at the history of the DAB article, I discovered that you are removing important contributions to this arcticle. I tried to make this article balanced, and cleaning out both both pros and cons from interesting facts, but right now this article is just bad. I’m seroiusly considering labeling the whole article as POV. —The preceding unsigned comment was added by Segrov (talk • contribs) 00:26, 30 December 2006 (UTC).
- Personally I think you are destroying the article and made it worse than before. An important aspect of Wikipedia is to let everyone contribute, but looking at the history of the DAB article, I discovered that you are removing important contributions to this arcticle. I tried to make this article balanced, and cleaning out both both pros and cons from interesting facts, but right now this article is just bad. I’m seroiusly considering labeling the whole article as POV. —The preceding unsigned comment was added by Segrov (talk • contribs) 00:26, 30 December 2006 (UTC).
- I find it amazing that *I'm* being accused of being POV when all I'm actually doing here is stopping the DAB fanatics from building a completely inaccurate page that would be no different from a glossy advert for DAB. Using examples that you yourself have done: why is variable bandwidth a benefit for DAB over FM? You've already got a sub-section on more stations; you've already got a section on DAB's better spectral efficiency (which obviously implies that it can carry more stations). So why is this a separate benefit that the bandwidth can be varied? And another of yours was about metadata and RDS. Auto-tuning is a STANDARD feature of RDS, and yet you tried to suggest that DAB not having to change frequencies was a benefit.
- And obviously an important element of Wikipedia is that a large number of people build the pages, but the crucial issue is that the information be correct, and I'm sorry, but Gaga-David makes up information, so I *will* revert things he says that are wrong. And the last change you've made was to revert back to his incorrect description of the situation with DAB in Sweden. The crucial parts where he's just making things up was where he said that the Swedish government has somehow overruled the cultute minister. No, the culture minister said that the old DAB system has no future in Sweden, and I guarantee that the old DAB system will not be used in Sweden, because it is completely inconceivable that Sweden will adopt the old DAB system now that DAB+ is around the corner, so nothing has changed whatsoever- renewing a licence to allow transmissions to continue is merely to allow tests of DAB+, not to stick with a system that both the outgoing and incoming Swedish governments have refused to use.
- The sad truth here is that the old DAB system is an old system that should never have been adopted without being upgraded first, and all you and a couple of other people seem intent on doing is trying to hide the old DAB system's problems that really are major problems. I fully support the new DAB+ standard, so as time goes by and more countries decide to use the new DAB+ standard, this page will become more positive about DAB, but until this happens DAB's problems should not be hidden. Digitalradiotech 11:14, 30 December 2006 (UTC)
- Well, if you are to sure that you posess the truth, then you should convert to some kind of religon. DAB is an issues that have both pros and cons. Sadly, this wiki-article is more about some kind of theroetic sound issue that only hi-fi enthusiasts would care about.
- You say that you are afraid that someone would make this an advert for DAB. If you ask me, a glossy advert would probably be for the better instead of this very long repetetive criticism about sound quality. Right now, the same phrase is repeated 3 times. That is not necesary.
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 agree, the whole article needs a makeover. The opening paragraphs should be dedicated at intorducing the whole concept of DAB, and not on some minor technical mumbo jumbo. I recently browsed thorught the edits done to this site, and i must say that the whole DAB-page seems to be hijacked by one or two digitalradiotech-kind of users.
- If other users agree, we could revamp the whole article. I suggest a typical wiki-article layout, with a brief introduction to the subject in the heading and a criticism-section at the end. I have several ideas, but i need some support from other users as i am afraid the whole changecould quickly be deleted by the same hi-fi enthusiast. Segrov 23:40, 19 January 2007 (UTC)
- Segrov, I agree totally. The article at the moment reads like nothing else I've seen on wikipedia handling a technical subject such as this. It really is turning into a copy of Digitalradiotech's web site (which I hadn't seen before it was mentioned here). Where there are criticisms, then put them in the right place, with the right references and add balancing material where it exists. I had an initial stab at this but it's been reverted, twice, which kind of discourages me from trying again.--Ian 12:28, 19 April 2007 (UTC)
Metainformation
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)
- AF (auto tuning) on RDS provides the ability to switch frequencies when listening to the same station, and I can't believe that this isn't standard on car stereos across Europe that use RDS. Digitalradiotech 13:00, 27 December 2006 (UTC)
- Metainfo is more than autotuning. it’s also about genres, songtitles and other useful info.
- AF if anything is auto-retuning rather than tuning - one still needs to know that BBC Radio 1 broadcasts on 98.3FM, but once tuned to that station your radio will stay on it. Very few FM radio's (I've only ever seen 1) have any sort of auto tune functionality (i.e. the ability to find all broadcast stations and present those in a list). Both DAB and FM have a form of frequency following - on DAB this allows a car radio to automatically retune to the same station as the local multiplex changes - i.e. your radio can stay tuned to XFM Midlands while driving between Mansfield and Cambridge by automatically tuning from 12C (Now Nottingham), to 11B (Now Leicester), to 12D (Now Peterbourgh) to 11C (Now Cambridge) - this is pretty much the same as the AF service on FM-RDS. However the implementation of this by some multiplex operators ((former) Capital and Emap being two offenders) means that it isn't seamless. Secondly there is also the ability to follow multiple local stations round - e.g. Hereward, Leicester Sound and Trent FM, or XFM Midlands and XFM West - where as the FM RDS implementation in the UK doesn't offer that (and I am unsure if this is possible). With regards to the additional stations - I have only ever seen the Programme Name, Now Playing and similar content provided by the BBC on their national stations and the former GWR "The Mix" stations.
- About the possibility of following local stations in the same media group via RDS - I believe it is technically possible, if the PI codes for both local stations are the same, then the tuner will switch to the other station. I believe I expierienced this once a few years back on my way out of Kent when my radio tuned from Invicta FM to Capital FM (formerly both Capital FM Network stations). While this is is possible, I'm not sure if it is good form to do so. I'm sure someone knows more than me about it though! James MSC 20:56, 9 January 2007 (UTC)
- Not quite so. The RDS transmitter has to be programmed with various AF frequencies for the receive tuner to know where to look. Its not based on PI codes. —The preceding unsigned comment was added by 86.4.28.112 (talk) 22:00, 9 January 2007 (UTC).
- About the possibility of following local stations in the same media group via RDS - I believe it is technically possible, if the PI codes for both local stations are the same, then the tuner will switch to the other station. I believe I expierienced this once a few years back on my way out of Kent when my radio tuned from Invicta FM to Capital FM (formerly both Capital FM Network stations). While this is is possible, I'm not sure if it is good form to do so. I'm sure someone knows more than me about it though! James MSC 20:56, 9 January 2007 (UTC)
- AF if anything is auto-retuning rather than tuning - one still needs to know that BBC Radio 1 broadcasts on 98.3FM, but once tuned to that station your radio will stay on it. Very few FM radio's (I've only ever seen 1) have any sort of auto tune functionality (i.e. the ability to find all broadcast stations and present those in a list). Both DAB and FM have a form of frequency following - on DAB this allows a car radio to automatically retune to the same station as the local multiplex changes - i.e. your radio can stay tuned to XFM Midlands while driving between Mansfield and Cambridge by automatically tuning from 12C (Now Nottingham), to 11B (Now Leicester), to 12D (Now Peterbourgh) to 11C (Now Cambridge) - this is pretty much the same as the AF service on FM-RDS. However the implementation of this by some multiplex operators ((former) Capital and Emap being two offenders) means that it isn't seamless. Secondly there is also the ability to follow multiple local stations round - e.g. Hereward, Leicester Sound and Trent FM, or XFM Midlands and XFM West - where as the FM RDS implementation in the UK doesn't offer that (and I am unsure if this is possible). With regards to the additional stations - I have only ever seen the Programme Name, Now Playing and similar content provided by the BBC on their national stations and the former GWR "The Mix" stations.
Regarding the channels for the Canadian usage of the L-band
Shouldn't that belong in the L-band article? -Daniel Blanchette 20:53, 16 February 2007 (UTC)
Text moved from Talk:Dab
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)
Edit war ....82.20.7.186
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)
- Hi, also unregistered user from IP 82.20.7.186 does not do edit summaries. When reverting sections, please add summary of edits and your reasoning (e.g., reverting to orig version...edit changed meaning too much..)Nazamo 17:06, 26 February 2007 (UTC)
- Hi Nazamo, I have noticed an identical behaviour from a user named DigitalRadioTech, and believe that he also is the person behind a decent handfull of other ip-adresses behaving just a similiar way doing the same things. In other words: one person is trying to control this website. I have read your edit, and i think it is a very good one. Luckily there are people working to preserve and improve on your effort, as you can see from the article history. Segrov 20:24, 6 March 2007 (UTC)
- I've just compared Nazamo's final contribution with the final edit provided by 82.20.7.186 (which was myself) [5], and "good faith" or not, I reverted the comments in the introduction because I considered them to be incorrect. That is not vandalism, that is simply seeking to provide accurate and unbiased information. For example, you said: "Unlike with FM, there is no hiss with a weak signal on a DAB signal". That couldn't be less balanced if it tried, because you are saying that FM has problems when it has a weak signal (obviously true) without mentioning that DAB has its own problems when the signal is weak. For example, I live 5 miles away from the transmitter for my local DAB multiplex, and that multiplex merrily bubbles.
- You also questioned "my credibility". Well, my job is to write about digital broadcasting for a UK hi-fi magazine, and I studied digital communications and DSP on an advanced course (as opposed to conversion course) MSc, and I've written an extensive website about digital radio technology. Digitalradiotech 10:36, 9 March 2007 (UTC)
- Hi Nazamo, I have noticed an identical behaviour from a user named DigitalRadioTech, and believe that he also is the person behind a decent handfull of other ip-adresses behaving just a similiar way doing the same things. In other words: one person is trying to control this website. I have read your edit, and i think it is a very good one. Luckily there are people working to preserve and improve on your effort, as you can see from the article history. Segrov 20:24, 6 March 2007 (UTC)
- Look, I have followed this debate over half a year now, and I am not the only one questioning your lack of objectivity. If you had bothered reading the talk-pages instead of reverting everything, then you might have noticed that there has been several complaints about your biased writings (And I am not refering to your fight with G.A. David). I know very well who you are, and I know that you are well renowned for having no credibility in the DAB-debate, despite your freelance writings for one hi-fi magazine. For instance, have a look at this site: http://www.avihifi.co.uk/ - it’s one of many websites complaining about you. Your credibilty is not doing very well...
- I exchanged a few emails with the managing director at AVI, and in one email he said: "I don't give a shit about MP2 or any coding for that matter". So I think I can live with being attacked by someone that thinks that the audio codec and bit rate is irrelevant. Oh, and please evidence about these other "many websites complaining" about me. And one last thing, if you know all about me, I think this begs the question who are you, and do you work on DAB? One thing I remember is that you're from Norway, and I know from correspondence with people in Norway that there is a handful of people that work on DAB in Norway who will not accept the views of anybody else about the audio quality on DAB. Are you and G.A. David 2 of these people, by any chance? It is all well and good slagging me off, but it is only fair that I know yours and GA David's background. If you're ordinary listeners, then I suggest you gain some respect for me, if you work on DAB then admit so.
- There is no need for me to elaborate on my background because unlike you i don’t pretend to be mr. very important. But you have huge problem. First you try to impress everyone with your background, but when we take a closer look, it’s all just fake. You are not the editor og even an employee of the Hifi-magazine you freelance for. I have read the email from Price. And you havent been writing for VG either (as you claim somewhere on this webpage). VG simply printed your letter to the editor.
- I don't make myself out to be Mr Very Important; the reason I've given information about myself was because my credibility was being called into question by Ga-David. And in your next paragraph, you call my credibility into questin again, and you even have the audacity of calling me a liar.
- Yes, you really do pretend to be someone very improtant when you demand me to gain some respect for you. Segrov 20:56, 18 March 2007 (UTC)
- Considering that you say I've got absolutely no credibility then yes, absolutely you should gain some respect for me. Digitalradiotech 22:43, 18 March 2007 (UTC)
- As you have read the email you mention, you must therefore be in or connected to the Norwegian DAB industry. Therefore, it is wholly unsurprising that you and your sidekick Ga-David are trying to hide the truth here -- presumably he is in the Norwegian DAB industry as well? Your industry is well-known for being extremely dishonest. For example, the email you mention that was sent to the editor of the magazine was obviously an attempt to get me into trouble. I had already exchanged a few emails with Oddvar Kirkbakk, and after someone in Norway had written (incorrectly) that I was the editor of the magazine, Oddvar Kirkbakk could have either emailed me to ask me, or (as I'm sure he did) emailed any of the numerous people in the UK DAB industry that he will know to find out that I'm not the editor. But no, he emailed the editor to try and get me into trouble.
- The reason why i read that email is because it’s in the public. The whole process of adapting DAB in Norway is a pretty transparent provess with most of the official documents available for those who wants to read them. If yor were such an expert about everything DAB, you should have known that. Segrov 20:56, 18 March 2007 (UTC)
- Then when he'd found out I wasn't the editor of the magazine, he went on to describe me as being a "music journalist", which is obviously a lie, because I write about hi-fi, not music. The section in the report about me also lied about me not understanding digital radio technology. As I've just said, I exchanged a few emails with Oddvar Kirkbakk (he emailed me first...) in which we discussed how good the technologies of which DAB is comprised are. And yet the section about me said that I don't understand the technologies at all, which is a blatant lie.
- Furthermore, I have never said that I'm an employee of the magazine I write for. All I ever say is that I write for them. I write at least one article per issue for the magazine, and usually more than one, so I think it is a fair description of what I do.
- And you are lying when you say that I've said that I write for VG. All I have ever said is that I have had articles published in VG and another national Norwegian newspaper. And you are lying when you said that I sent a letter to the editor that was published. I was asked to write an article, and that article was then printed in VG. Digitalradiotech 15:01, 18 March 2007 (UTC)
- Readers letters are not the same as an article. Your "article" was published under a huge header clearly stating that it was readers letter, so you are obviously not telling the truth here. [3]Segrov 20:56, 18 March 2007 (UTC)
- Firstly, that link is to a file upload website, so where did you originally find that file? I'm afraid that I still think you are in the Norwegian DAB industry.
- I suggested to the same person that had asked me to write an article for DG(?) that it would be a good idea to write an article after Prof. Holm's report. He agreed, and he said he'd be able to get it printed in a paper, so I wrote the article. I did not send a reader's letter to VG, so you are lying. Furthermore, the suggestion that I've "finally" got one of my reader's letters printed is absolutely typical of the dishonest Norwegian DAB industry, because I have never sent a reader's letter, not least because I don't speak Norwegian and never read Norwegian newspapers. Digitalradiotech 22:43, 18 March 2007 (UTC)
- After reading your ramblings on this page, it’s more obvius than ever that you are an ordinary person with a i-hate-dab-agenda. Maybe you have know something about radio, but since you have been caught several times in not telling the truth, there is simply no reason anyone should trust you. Your credibility is non-existent, and since you can’t find any references confirming your claims, you should stand down and let your writings be corrected. If not, I will have to label this page as disputed. Segrov 20:35, 17 March 2007 (UTC)
- Please provide a single example of me not telling the truth! I hate liars, and I will not descend to yours or the rest of the DAB industry's level. And the only accusations of me lying consist of lying about me lying!!! Just look at your accusations of me not telling the truth above, with regards who I've written for. I've told the 100% truth here, but you've tried to accuse me of saying that I'm the editor of the magazine and that I'm employed by the magazine and that I've "been writing for VG". These are all untrue and I have not made ANY of these claims - but they're all good character slurs, aren't they?...
- And I find it amazing that someone from the Norwegian DAB industry has the audacity to suggest that I have no credibility!! It was incompetent of the UK to launch the old DAB system in 2002, but Norway was the last country to commercially launch the old DAB system in around 2005 and DAB sales have been very, very low and you will have known that DAB+ was being designed from October 2005 yet you've continued with the old DAB system. That, my friend, is gross incompetence, let alone lacking in credibility! Digitalradiotech 15:01, 18 March 2007 (UTC)
- You must be quite desperate when youre guessing that I’m working for the DAB-industry. I’m just a john doe who sees through your charade. Segrov 20:56, 18 March 2007 (UTC)
- Where did you find the scan of my article then? Digitalradiotech 22:43, 18 March 2007 (UTC)
- And on the subject of my credibility, I've been saying for about the last 3 years that DAB is inefficient and that DVB-H and DMB are better systems to use because they are fara more efficient due to their use of AAC+ and RS error correction coding. What has DAB+ just adopted? AAC+ and RS coding. Suffice it to say that I could not care less about anybody that questions my credibility, because I seem to have a knack of getting things correct. Digitalradiotech 23:39, 12 March 2007 (UTC)
- I judge Nazamos edit to simply be more correct and neutral than your version. It is well written with a good flow, and it also includes your point of view. Nazamos edit is just what the DAB article needs. Nazamo is more in thouch with both the pros and cons, while you seem to be only interested in the cons. Segrov 21:23, 11 March 2007 (UTC)
- I changed his version because it was inaccurate. Digitalradiotech 23:39, 12 March 2007 (UTC)
- To bad you changed it a version with false claims made up by yourself.. You should change it back. Segrov 20:35, 17 March 2007 (UTC)
3RR
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.
- DAB was developed for several reasons, and your claim about sound-quality is a highly dubious one as youre point has nothing to do with the sound ordinary people are experiencing, but instead seems to be about bitrate broadcast quality. 195.159.3.166 16:45, 9 March 2007 (UTC)
- In the first paragraph of the first section of the DAB specification document it says: "1 Scope - This European Telecommunication Standard (ETS) establishes a broadcasting standard for the Digital Audio Broadcasting (DAB) system designed for delivery of high-quality digital audio programme and data services". I'm afraid there's no escaping from the fact that DAB was intended to provide high audio quality. Digitalradiotech 19:18, 9 March 2007 (UTC)
- Yes, but DAB were also created with several additional challenges in mind, like better economics and simpler to use. So it is wrong to only focus on one aspect of DAB. Also, the sentence about Digital transmission techniques makes up a nice introduction for DAB, as DAB is a Digital transmission technique. Not everyone knows that, and there it is in its place. A long article like this really benefits from a brief introduction before narrowing the text on more specific DAB-aspects... Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- The sentence starting "Digital transmission techniques were developed because" is nonsense. This is a page about DAB, not about digital transmission techniques. Digitalradiotech 00:02, 13 March 2007 (UTC)
- So DAB is not a digital transmission technique? Ga-david.b 15:05, 16 March 2007 (UTC)
- No, DAB is not a digital transmission technique! DAB is a system. Digitalradiotech 16:48, 16 March 2007 (UTC)
"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.
- No, this sentence does not imply DAB perfection - it simply implies that DAB is far better than FM at this particular point. 195.159.3.166 16:45, 9 March 2007 (UTC)
- It is obvious that that sentence tries to assume that DAB doesn't suffer from problems with weak signals, which is nonsense. Digitalradiotech 19:18, 9 March 2007 (UTC)
- Well, DAB have less problems with signals, so i don’t really see a problem with at sentence implying that DAB has less reception problems than FM. Why do you want to try to hide such a fact? Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- A weak signal is by definition a problematic signal on whatever system you are referring to. Digitalradiotech 00:02, 13 March 2007 (UTC)
- It’s far less problematic with DAB. It’s as easy as that. Ga-david.b 15:05, 16 March 2007 (UTC)
- Try re-reading what I said until you understand it. Digitalradiotech 16:48, 16 March 2007 (UTC)
"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.
- And I can assure you that i hear that 128kbit DAB sounds better on my desktop that any FM signal i can receive. And most people cant hear the difference, but preferes less hiss and noise, so your claim is very dubious. There have been done very fex listening test on ordinary table radios, but most people can listen, and they are just as right as you when the disagree with your preference. 195.159.3.166 16:45, 9 March 2007 (UTC)
- I see that below you've referred to what Professor Holm said in his report, but here you're saying that he's wrong. So we've got a professor of signal processing saying that DAB sounds worse than FM, we've got someone that took a PhD in perceptual audio coding (the exact field of reduced bit rate audio coding) that says that DAB sounds worse than FM, we've got engineers from the BBC R&D department implying that DAB sounds worse than FM, and you've got me, someone that writes about DAB for a living and who reviews DAB/FM tuners and portable radios saying that DAB sounds worse than FM. So, could you enlighten me what experience you have that allows you to tell all of these people that they're wrong and you're right? Digitalradiotech 19:18, 9 March 2007 (UTC)
- Oh my, you havent read prof. Holms report, have you? Well, to bad for you, as Holms summary is very clear about that the quality problems only occur on proper stereo systems, and table radios are most often mono. Prof Holm also thinks DAB is a good thing, but he simply wants more bandwidth. He suggest that 160kbits are enough for most channels to match FM in sound quality, but research from the broadcasters shows that most listeneres by far can’t tell the difference between 128kbits and 160kbits. So here you have a proper professor opposing you, a freelance writer with a master degree. Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- Of course I have read Prof. Holm's report - the summary is written in English. As well as the issue about stereo, he said that the sound quality on DAB was flat due to the bit rate levels being too low and he actually said that 160 kbps should be the minimum bit rate level used and that "The reason is that the bit rates for all the channels in the Norwegian DAB network today are much lower than what scientific evaluation of audio quality has recommended, i.e. lower than 192 - 256 kbps which was projected when DAB was debated in Stortinget (Norwegian Parliament) in 1998." and "More demanding material should have the same quality as mp3 at 128 kbps, i.e. 192 kbps in DAB." and "The broadcast companies want us to make a choice between FM, with the best audio quality in stationary receivers". As usual, you are completely ignoring facts that you don't like. And in complete contradiction to what you've just said, Prof. Holm clearly agrees with what I'm saying. Digitalradiotech 00:02, 13 March 2007 (UTC)
- Prof. Holm says 160kbit equals FM.
- Prof. Holm says 160 kbps has "an audio quality similar to FM". Get your facts right. Anyway, I disagree with Professor Holm about this. Digitalradiotech 16:48, 16 March 2007 (UTC)
"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+.
- So then you agree with FM being worse than DAB in the car. This is BTW just the same as Prof. Sverre Holm says in his report on DAB audio where he writes the following "The broadcast companies want us to make a choice between FM, with the best audio quality in
stationary receivers, and DAB which is best in a car." [4] 195.159.3.166 16:45, 9 March 2007 (UTC)
- Do you not see the contradiction in quoting Prof. Holm saying "FM, with the best audio quality in stationary receivers" and above claiming that DAB sounds better than FM?????? Digitalradiotech 19:18, 9 March 2007 (UTC)
- The point here is that Holm is very clear about DAB being the superior solutions for car radio, even with todays bitrates. You see, Holm doesnt have a bias problem, so he can be honest about facts like this. Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- He says this about what DAB should offer but doesn't: "Reception without garbling in cars". That hardly backs up what you're saying. Digitalradiotech 00:02, 13 March 2007 (UTC)
- Then read again: "...DAB which is best in a car". It’s as easy as that. Ga-david.b 15:05, 16 March 2007 (UTC)
- But he also says: "Reception without garbling in cars", which implies that his experience of DAB reception isn't good in cars... Digitalradiotech 16:48, 16 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.
- You basically saying that this is correct (and we all know DMB share the same broadcast system as DAB, and also transmit DAB for audio-only broadcasts) so why remove it? 195.159.3.166
- Err, no, I'm saying there's 2 versions of DAB, which is obviuosly true, because there's DAB and there's DAB+. Digitalradiotech 19:18, 9 March 2007 (UTC)
- DMB is a DAB-based standard wich truly shows the flexiblity of the system. Why do you want to hide this fact? Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- This is a page about Digital AUDIO Broadcasting, not mobile TV. DMB is a mobile TV system. Also, DMB cannot be a version of DAB, because it's called DMB.
- Obviously you are not that expert you claim that you are. What kind of uni gave you your title? I seriuosly suspect for trying to hide that you don’t have the education that you claim to have. Ga-david.b 15:05, 16 March 2007 (UTC)
- I'm certainly not going to say which universities I've attended considering that you seem to be unhinged and showing a propensity to stalking. But suffice it to say that I do have the qualifications I say I have, and couldn't care less if you don't believe me. Digitalradiotech 16:48, 16 March 2007 (UTC)
"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.
- Several receivers kan be upgraded: Keenwood and JVC makes stereos where the DAB-module can be exchanged for a different one, and several other radios claim that they are upgradeable - as for example Pure The Bug. 195.159.3.166 16:45, 9 March 2007 (UTC)
- The Frontier-Silicon Chorus 1 DAB receiver chip is not powerful enough to support DAB+ according to Frontier-Silicon, and all of Pure Digital's existing products use the Chorus 1 chip, therefore The Bug is not upgradeable to support DAB+. As for the car stereos, the fact that you can take a module out and put another back in its place at extremely high cost is not what I call "upgradeable", because I'm talking about software upgradeability. Digitalradiotech 19:18, 9 March 2007 (UTC)
- Well, the sentence you removed were talking about upgrades i general. That means both hardware and software upgrades. So i suggest you leave this... Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- Upgrading the hardware in a receiver is either impossible or unfeasible expensive - i.e. it is cheaper to buy a new receiver. Therefore, software upgradeability is the only relevant form of upgradeability. Digitalradiotech 00:02, 13 March 2007 (UTC)
- No, it’s not. And anyhow, earlier you said that this WERE correct - there are software-upgradeable radios. Ga-david.b 15:05, 16 March 2007 (UTC)
- There is ONE software-upgradeable DAB radio, which isn't even available in the shops in the UK, and I doubt it will be in Norway either. Digitalradiotech 16:48, 16 March 2007 (UTC)
"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)
- then simply edit the text about Switzerland instead of removing this piece of important information. 195.159.3.166 16:45, 9 March 2007 (UTC)
- Look, if you're going to continue to revert back to edits that contain lies then I'm going to revert straight back to an honest version. Okay? Digitalradiotech 19:18, 9 March 2007 (UTC)
- I’m not lying. I write in good faith, and when i see inforamtion that are misleading, i will try to improve upon it. I will remove switzerland from the list, and I suggest that you leave this sentence alone for now. Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
- The version you revert to is incorrect. Digitalradiotech 00:02, 13 March 2007 (UTC)
- It’s probably more correct that your version since you are not able to back up our claims. Ga-david.b 15:05, 16 March 2007 (UTC)
- Just to add something: After both myself and the Norwegian person were asked to discuss this issue on here, the other person has simply reverted back without discussion. I'm sorry, but if he cannot justify his claims on here whereas I am perfectly willing to justify ALL the claims I make, then I feel well within my rights to revert back to the correct version. —The preceding unsigned comment was added by Digitalradiotech (talk • contribs) 16:11, 9 March 2007 (UTC).
- I beg you pardon - the article history clearly shows that you reverted before discussing here. Now you are critisizing me fr doing the same thing? Also - remember that I did not write the intro at first, so I am not the one who should defend it, but I will defend the text because it is so obvius that you are misleading readers in this case. 195.159.3.166 16:45, 9 March 2007 (UTC)
- Sorry, but I don't understand your gibberish. Digitalradiotech 19:18, 9 March 2007 (UTC)
- I’m impressed. Ga-david.b 17:06, 12 March 2007 (UTC) aka 195.159.3.166
A "neutral" point of view
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 prefer DigitalRadioTech's version of the first line "The original objectives of converting to digital transmission...". However, the next sentence ("However, ...") presents only the most negative case, and should be qualified with something along the lines of "At appropriate bit-rates, these objectives can be achieved...".
- I think your suggestion is a good one. I suggest you edit these sentences as you think they should sound. Ga-david.b 14:43, 16 March 2007 (UTC)
- I think that's implied by saying that bit rates below 192 kbps sound worse than FM, but I'm willing to be flexible if I can agree on the wording.
- DigitalRadioTech, could you explain how the figures on your site for the breakdown of bit-rate vs. country has been compiled from the source at [7], as it's not immediately obvious? (Self-referencing is only a good idea if the reference can withstand scrutiny; otherwise, it raises questions of bias.)
- I simply count the instances of radio stations using different bit rate levels on the individual country pages / sections of a page on [8].
- I might also add that linking to your own site that states "DAB sounds worse than FM" as its opening title will not endear editors to assume that you are taking an unbiased stance on the issue. Oli Filth 01:23, 13 March 2007 (UTC)
- I'm not going to remove "DAB sounds worse than FM" from the header of my web pages, because I think it's an important part of my website, and I provide honest and accurate information on my website despite what others would have you believe.
- Feel free to put whatever you like on your own website. What I'm pointing out is that when you self-reference to such a website, it is then very easy for an editor with an opposing view to claim that your edits are biased, or that you're trying to push your own agenda upon the reader. Whether or not this is the case, I have no idea, I'm merely pointing out a potential problem.
- Ultimately, if I'm referring to information on my website that is factually correct then that's all that should matter.
- Gosh, and you claim to have a university education? But still you don’t understand simple concepts like credibility, and that information from you website is NOT credible? You know, if you HAD been credible, than you wouldnt need to accuse everyone else of lying all the time. Since you can’t back you claims with anything credible, i will edit this article to something more along Oli Filts suggestion. Ga-david.b 14:43, 16 March 2007 (UTC)
- The claim that "below 192 kbps ... which means that they sound worse than FM" does not agree with the cited reference, which specifies that "160 kbps = about the same as FM, but sometimes better, sometimes worse". Therefore, either the claim needs to be changed, or the percentage needs to be altered to show the number below 160kbit/s.
- You are not the only one who has observed this. Dr. Sverre Holm, Professor of signal processing at the Centre for Imaging, Department of Informatics, University of Oslo, claims that 160kbps will suffice to achieve a sound quality comparable to FM. [5] Also of note is that Prof. Holm bases this statement Soulodre § al. "Subjective evaluation of state-ofthe- art two-channel audio codecs,” (J. Audio Eng. Soc. 1998, vol. 46, no3, pp. 164-177.).
- Furthermore it is also of interest to notice that several broadcasters have replied to this study, an pointed out that dr. Gilbert Soulodres has monitored the sound quality on DAB through frequent evalutaions, and this is necesary as the encoders are being improved frequently. You can have a look at the charts on this page to see that the sound quality is probably even better than FM on 160kbps: [6]. Unfortunately I can’t find these published in an approriate journal, so I can’t reference these samplings properly on Wikipedia. So until we find a proper reference, i would settle with the claim that 160kbps generally equals FM. Ga-david.b 14:43, 16 March 2007 (UTC)
- The reference is to a web page that consists of David Robinson's submission to an Ofcom (or Radio Authority) consultation, and I know that David used FM samples with poor reception for that listening test, and he now considers that FM provides better audio quality than what he put in his results and he co-authored an article with myself in which we said that Radio 3 on FM sounds better than Radio 3 on DAB, and Radio 3 uses 192 kbps on DAB.
- If there is a source that corroborates this, then you need to find it and specify it in the article, and find a suitable reason as to why the claims in the current link are incorrect (from an objective point of view). At the moment, the article text and the cited reference disagree; this is not an adequate situation.
- Also, from my own listening experience, FM sounds better than all 192 kbps MP2 radio stations on DAB (that's Radio 3 only) and on the digital TV platforms, so it is simply massively incorrect to suggest that FM doesn't sound better than even 160 kbps. So no way will I accept this under any circumstances.
- Unfortunately, your own experiences are neither here nor there when it comes to providing information on Wikipedia, as this would be original research. What is important is verifiability. The current reference cites information that appears to be based on a listening test with a sample population greater than 1 (the use of error bars would imply this!); if your own subjective personal experience disagrees with this, there's not a lot that can be done about it, I'm afraid.
- With regards to the listening test, it was only David Robinson that carried out the test, and the error bars were for different audio samples.
- According to that webpage [9], the data was taken from a paper by Soulodre et al, from the JAES, and therefore not carried out by the author of the webpage.
- The MP2 data points will be, but David Robinson did the FM testing himself from samples he'd got from people at the same uni he was at at the time and the reception quality of these samples was poorHe now owns a Denon TU260L Mk II FM/AM tuner, and his opinion of FM quality is a lot higher than it was.
- You raise a good point that the source of the FM metric is not provided. (However, his opinion is of no relevance!)
- He didn't need to provide a source, he did it himself. He does have a PhD in perceptual audio coding, which happens to be the exact field we're discussing here. So if you're saying that his opinion is of no relevance because he's just some ordinary Joe then I'd suggest that you're getting a little bit too big for your boots here. Furthermore, since when did the views of hi-fi journalists become irrelevant all of a sudden when talking about audio quality???
- His opinion is of no relevance because on Wikipedia, people's opinions are not reliable sources of information.
- The best you can hope to achieve (currently), is to find a verifiable reason why Robinson's webpage is unreliable or incorrect, and then remove the link. But then the claim in the article would be unsubstantiated, and would also have to be removed.
- You see, this illustrates the core of the problem here: We have a person – Digitalradiotech – editing Wikipedia, beliving he is an important authority on DAB-issues. I believe that his writings on this article has a mis-informing agenda, and his own website also suggests this. Ga-david.b 14:43, 16 March 2007 (UTC)
- I've changed the link to an article published in the October 2005 issue of Hi-Fi World magazine. Digitalradiotech 10:50, 13 March 2007 (UTC)
- This brings me back to the problems with citing ones' own website. The PDF you linked to was created today, at the same time as your last edit to this article, so you evidently placed it on your site for the specific purpose of providing support to your side of the argument. The fact that you can add or change, at will, anything on your site to provide corroboration to edits that you make here is clearly a dangerous state of affairs; what's to stop me, Ga-David, or anyone, doing exactly the same thing?
- You didn't have any problems linking to my website before, and you merely said that I might get some people's backs up because I dare to tell the truth by saying that DAB sounds worse than FM. Anyway, I've tried taking pictures of the article in the actual magazine: [10] [11]. They're as good as I could get them, I'm afraid, but you can make out the text if you compare it with the PDF. And the only thing I changed in the PDF was to add the issue date and the magazine it was published in.
- That's actually not what I said or meant. I mentioned that self-referencing should particularly be able to withstand scrutiny (implying "with respect to verifiability, no original research, and neutral point of view"), more so than other references, as it could be easily be construed that you might be forcing a bias. The ante is raised yet further if the sources being cited are augmented to suit the current status of the Wikipedia article.
- This isn't merely self-referencing, this was an article about DAB published in a respected hi-fi magazine.
- This is an article written by you, so it is an over-obvius example of self-referencing and it should be removed. Ga-david.b 14:43, 16 March 2007 (UTC)
- Even so, Wikipedia policy is not overly-keen on self-referenced material.
- The problem is exacerbated by the fact that any attempts to web-search for the title, etc. of the article you posted on your site returns nothing. Now, I'm not suggesting for a moment that you faked the article (I assume that you are editing here in good-faith), but of course, any editor with an opposing view would be justifiably free to make such a suggestion.
- The fact that this Hi-Fi World article turns up no Google hits also implies that it's never been cited, meaning that it is less than notable. The fact that it itself cites no references for its claims, means that is also not verifiable. Anyone would be entirely justified in claiming that such an article is not a suitable reference for a Wikipedia article.
- You won't find this article on the Internet, because I've only just uploaded it today.
- …And it’s not being neither cited nor mentioned because the author is not worth citing. The author has a big reputation of having an agenda, and therefor he is not credible. The author is Digitalradiotech. Ga-david.b 14:43, 16 March 2007 (UTC)
- The fact that there is apparently a source (Souloudre et al) with an alternative result (not to mention, a peer-reviewed, widely-cited source), means that merely stating "they sound worse" in the Wikipedia article is not verifiable, as it is disputed. Either an appropriate reference should be used, or a more rounded discussion of the available sources should be added, or all such blanket claims removed completely. (I am aware that the quantitative difference between the two sides of this particular argument is small, almost insignificant, as most stations are at 128kbit/s, so quibbling over 160 v. 192 seems beside the point. However, it does seem be subject to a large number of edit reversions.)
- Soulodre says nothing about FM. An appropriate reference has been provided, which is what you wanted.
- With respect, I'm not sure the reference is appropriate. As I mentioned, it doesn't state any references for its claims, and is apparently not notable. I'm sure I could find (if I looked for long enough) a third-party article of equivalent merit that states the exact opposite, publish it on my own website, and link to it here.
- The difference between you and David Robinson is that you're a recent graduate with an MEng degree and you've admitted that you know nothing about DAB, and he's got a PhD in the field that's being discussed. And if you still doubt whether he knows what he's talking about, he did invent this: [12] which happens to be supported by a few apps: [13].
- I'm wasn't attempting to compare myself with anyone, nor Robinson (I'm not sure how you managed to infer differently). I'm talking about the use of an uncited, unsourced (as in "it provides no references for its claim") magazine article as a reference (the one from Hi-Fi World). What I'm saying is that there's almost certainly an article in a magazine somewhere which makes an off-hand claim that (for example) 160kbit/s DAB is fine, but equally uncited and without references. What makes one more valid/reliable/etc. than the other?
- In general, the more contentious (or disputed) the claim, the greater the importance placed on the nature of the reference used to support the claim. The issue in question here ("<192kbit/s DAB sounds worse than FM") is clearly disputed, clearly contentious (at least as far as this Wikipedia article is concerned), and inherently a subjective notion. The only objective approach to reducing the subjective nature of the problem is to perform properly-conducted MOS tests with a suitable sample size.
- The Norwegian person contending this has admitted that he owns a DAB portable radio and a DAB car stereo. Other than that, and despite having asked him, he's provided no evidence that he has any knowledge about DAB other than the fact that he's bought a DAB radio! Suffice it to say that I think it is ridiculous that I'm even discussing this with you.
- Assuming a reference of this nature can be sourced, even then such blanket statements are misleading, at best. An analogy (albeit a weak one) would be the blanket claim "all humans prefer Coca-Cola to Pepsi", based on the result of a double-blind study. Something to the effect of "To the majority of listeners in the majority of situations with the majority of audio sources..." would perhaps be an appropriate qualifier. Oli Filth 23:33, 13 March 2007 (UTC)
- Coke and Pepsi have a different taste, and some prefer Pepsi and some prefer the taste of Coke. Nobody prefers lower to higher audio quality unless they're feeble-minded - I am willing to put a caveat after the claim that says that feeble-minded people prefer the sound of DAB, if that would help. Digitalradiotech 00:49, 14 March 2007 (UTC)
- The salient point of the analogy was the use of a study based on a limited sample (with a spread) to make blanket claims framed as if they were objectively true. Oli Filth 16:20, 14 March 2007 (UTC)
- Let me state again (as I imagine I'm at risk of appearing to take sides here) that I have no expert knowledge of DAB, nor opinion on the matter, nor vested interest in either side of this argument. My interest is in stabilising this article so that it is usable, and adherent to Wikipedia policy. Oli Filth 20:13, 13 March 2007 (UTC)
- Well, I've provided a good faith reference, so surely it's all sorted now? Digitalradiotech 22:25, 13 March 2007 (UTC)
- The "With mobile reception" should be expanded upon (e.g. "such as car radios"), as to the average reader, it may not be entirely obvious what this refers to.
- I agree, an would also like to add desktop radio as these also have more frequent reception issues with FM, wicth distorts the sound. As i pointed out to Digitalraditech: Prof. Sverre Holm only states that the sound problems appear on proper stereo systems, and desktop radios i general are mono. Ga-david.b 14:43, 16 March 2007 (UTC)
- Fair point.
- Whilst DMB might not be a "version" of DAB, it is certainly based on DAB (it uses the main logical channel of DAB, and therefore uses the entire DAB PHY, as I'm sure you're aware). It would we well worth at least mentioning its existence, with a link to the DMB article.
- I agree. And since DMB also can be confused with DAB, it is important to have this information close to the top of the article, as this is of useful information to the reader. Ga-david.b 14:43, 16 March 2007 (UTC)
- This page is about Digital Audio Broadcasting, so the thing that I object to is the Norwegian person trying to suggest that there's 3 versions of DAB, and DMB cannot be a version of DAB because it's got an 'M' in the title! I don't mind there being a link to DMB, but I don't accept that DMB is a version of DAB.
- If the introduction is going to state that "receivers that support the new DAB+ standard are expected to be in the shops by summer 2007", the availability of DAB+ services should be mentioned.
- Nobody knows exactly when DAB+ services will be available in the UK, but Malta wants to launch in July and New Zealand wants to launch in December.
- In that case, the "non-availability" of DAB+ services should be mentioned!
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)
- Yes, you have definetly been of help. I hope more people engage in this dialog as well. Ga-david.b 14:43, 16 March 2007 (UTC)
- Whether it helps or not will depend on whether you're trying to suggest that FM sounds no better than 160 kbps MP2. Digitalradiotech 02:37, 13 March 2007 (UTC)
- I'm not suggesting an opinion on this either way (because in all honesty, I neither know nor care). What I'm attempting to do is see if the current parties can approach a compromise, and also pointing out current flaws with the two versions of the introduction. Oli Filth 08:33, 13 March 2007 (UTC)
- If you have a look at DigitalRadioTechs talk-page (look at the history) then you will se that this is not the first time we are discussing. As you also can see, Digitalradiotech has not answered me elsewhere, suggesting that he might give up on this article. Digitalradiotech probably has a lot of knowledge in DAB, but unfortunaltely i can’t trust his information, and therefore I have tried to unbias and clarify the text as it has been the source of misunderstanding for a lot of people. Ga-david.b 14:43, 16 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.
- Thank you for willingly sharing your bias. Now, please find some sources people can trust when it comes to this sound-quality question. If you have a university degree, i guess you should have known about credibilty when referencing. Ga-david.b 13:00, 19 March 2007 (UTC)
- It's not a bias, it's the truth. Digitalradiotech 15:41, 19 March 2007 (UTC)
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".
- Well, it is proven that you are an infamous DAB-hater, and everyone can see that. Most people wont bother paying attention, but when. You even admit it yourself. How can wikipedia trust your information? Wikipiedia is an encyclopedia, not a soap box fro your personal opinions. Ga-david.b 13:00, 19 March 2007 (UTC)
- I don't hate DAB at all; I think the old DAB system is a very poorly designed system, and should never have been launched in the UK or elsewhere. But I support DAB+, so how can I be accused of being a "DAB-hater"?? And as for you having the audacity to accuse me of being biased, your edit changed 99%, which was a value that was referenced (and anybody could verify if they took the time to cound the number of stations transmitting at those bit rates), to "most", and you added ridiculous nonsense like "some FM stations some of the time". Basically, you are trying to hide the truth. I wonder why that is? Could it be that you work in the Norwegian DAB industry? They're infamous for being dishonest. Digitalradiotech 15:41, 19 March 2007 (UTC)
- Hint: your webpage gives you a credibility-problem. Ga-david.b 16:24, 19 March 2007 (UTC)
- My website has been suggesting for the last 3-4 years that systems that use AAC+ and RS coding should be used instead of the old and inefficient DAB system. WorldDMB have belatedly done exactly what I suggested they should do 3-4 years ago. Sorry, but I'm not the one with the credibility problem here. The people with a credibility problem are the Norwegian broadcasters. Which one do you work for, BTW? Digitalradiotech 17:30, 19 March 2007 (UTC)
- Sorry, have checked you claim of "creating" a DAB version with ACC-support, but i cant find your name in the references. Could you please provide som proof that the WordDMBforum is acting on your suggestion? Ga-david.b 22:21, 21 March 2007 (UTC)
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.
- The truth here is that your claims is contradicted by several people with Ph.D’s and therefor you claims are proven wrong. Ga-david.b 13:00, 19 March 2007 (UTC)
- I've told you before that David Robinson now thinks that FM sounds a lot better than he did when he carried out the listening test that I referenced, and the FM recordings that he used when he took the test were from a friend who had poor FM reception. As I say, all you're trying to do is hide the truth using technicalities. Digitalradiotech 15:41, 19 March 2007 (UTC)
- This is not relevant. Stick to facts, not personal opinions and other hersay. Get David Robinson, Gilbert Soulodre and Sverre Holm to change/update their reports to reflect this, or simply stop writing this kind of nonsense. Ga-david.b 16:24, 19 March 2007 (UTC)
- Okay, I've changed to a version that you CANNOT change. I have references that prove that 128 kbps sounds worse than FM, and 92% of stereo stations on DAB in the countries mentioned use bit rate levels of 128 kbps or below. I'm only doing this to shut you up, although I consider you and Segrov to be liars that work in the Norwegian DAB industry, and I don't really want to do this, and I'm only doing it because you're wasting too much of my time. Do not change anything else, and if you do I will just change it back without entering into discussion.
- It’s still biased and ignores the fact sound-qualtiy is far more than bitrates. But relax - I improved it for you. Hope to see you here again if you like to discuss these edits. Ga-david.b 22:21, 21 March 2007 (UTC)
- There is NOTHING WRONG with my credibility. I understand this technology FAR, FAR better than the people IN CHARGE of engineering at P4 and NRK!!! The emails I received from Oddvar Kirkbakk showed an almost complete lack of understanding of the important issues relating to DAB, and he's in charge of engineering at your national public service broadcaster! The same can be said for Paul Samsoe at DR (Denmark). The problem is that the broadcasters are basically clueless about digital technology. And there's an added problem with the Scandinavian public service broadcasters, because they naively seem to think that the BBC can do no wrong. Well, I'm afraid you're wrong. The BBC stopped being interested in engineering in the mid-1990s, so if you blindly follow whatever the BBC does, like you have done with DAB, God help you. Digitalradiotech 17:30, 19 March 2007 (UTC)
- Oh dear. How can one argue against a huge ego? Ga-david.b 22:21, 21 March 2007 (UTC)
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.
- Your personal opinions are welcome at your own webpage. Please stick to facts. Ga-david.b 13:00, 19 March 2007 (UTC)
- The above paragraph is not personal opinion, it is absolutely obviously true, and if you had any idea what you were talking about you would be able to see that. For example, NICAM, which uses a bit rate of around 724 kbps, is used by the BBC to distribute the signals to the FM transmitters. Now, surely you can understand that a digital stream with a bit rate of 724 kbps is effectively guaranteed to sound better than one at 192 kbps?? NICAM is basically 14-bit samples intelligently companded down to 10-bit with a 32 kHz sampling frequency. So if you then transmit that as an FM signal and you have a good SNR at the receiver you're basically getting very nearly CD-quality. If you can't understand that, then you shouldn't be editing this page. Digitalradiotech 15:41, 19 March 2007 (UTC)
- Major broadcastes stores all it digital music in MP2, with bitrates betwenn 192kbps and 256kbps. So how NICAM cant improve this sound. But these details don’t matter, because what matters is that you are not able to find any sources that can verify your personal opinion on this matter. Ga-david.b 16:24, 19 March 2007 (UTC)
What's happening on here is simply people trying to hide the truth using technicalities. Digitalradiotech 16:34, 16 March 2007 (UTC)
- To sum this up: DigitalradioTech has not been able to back his claims, and therefore i will remove his edits from the intro and replace them with credible information from Prof. Sverre Holm, Dr. David Robinson and Dr. Gilbert Soulodres. Ga-david.b 13:00, 19 March 2007 (UTC)
- And I will simply correct your claims. Digitalradiotech 15:41, 19 March 2007 (UTC)
- Go ahead, but provide credible sources for your information, or i will have to correct you once again. Ga-david.b 16:24, 19 March 2007 (UTC)
About the continous edits from DigitalRadioTech and why I keep reverting them
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)
- There is a bad situation developing here. One man's personal views are being imposed on this article while balancing improvements by others (that still leave criticisms on DAB where they belong) are reverted without comment. It really does look like Digitalradiotech won't settle for any introduction to the DAB standard that doesn't then immediately slam into criticising how it's being used in his own country. Even my addition of balancing links to end user surveys in the UK showing high levels of consumer satisfaction with DAB broadcast quality didn't survive. --Ian 12:36, 19 April 2007 (UTC)
- Yes, the situation is bad. I had some spare time earlier, and had the chance to help this article. But right now it is little i can do. DigitalRadioTech is not employed and can probably spend the whole day doing nothing but reverting this article. But I am wondering if i should label the article as POV. What do you think? Ga-david.b 18:29, 30 April 2007 (UTC)
3RR again
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)
Digital audio broadcasting should not redirect here.
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)
Why is this article still so biased and non-encyclopedic?
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.
- It is absolutely inevitable that DAB+ will replace DAB. For example, there's 120m - 150m FM radios in the UK, and there's only 5m DAB radios, and now DAB+ radios have started to appear and by this time next year the vast majority of "DAB" radios on sale will be DAB+ radios. The UK broadcasters privately admit that DAB+ will replace DAB and Ofcom privately admits that DAB+ will replace DAB. 81.107.219.7 11:46, 24 August 2007 (UTC)
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.
- Firstly, all of your edits to this article are highly technical, and they are therefore not appropriate for this page. If you want to start a new page on DAB technology then go ahead, but highly technical sections are not appropriate. One good example of one of your edits that no-one has ever removed is your explanation of DAB's superior spectral efficiency. Nobody other than people who've actually studied engineering to degree level will understand or be interested in what you wrote, so it's therefore not on the right page. There is a place for highly technical explanatinons, but this page is not that place.
- And DAB is not based on statistical multiplexing. If you think it is based on stat-muxing then explain how you can justify the use of the word "statistical". For something to use statistical multiplexing then there has to be some probability element at work and where there should be some time variability, but that doesn't apply with DAB. 81.107.219.7 11:46, 24 August 2007 (UTC)
So please everyone, try to use a more objective language.
Some suggestions for improvements:
- Don't put controversial stuff in the article lead. Instead different sections may state the arguments for and against DAB.
- The content in the article head is highly appropriate, so it should stay where it is. 81.107.219.7 11:46, 24 August 2007 (UTC)
- Move engineering details to the appropriate section instead of deleting it.
- I would suggest starting a new page for the engineering aspects of DAB. 81.107.219.7 11:46, 24 August 2007 (UTC)
- I would like to see a table in the end of the article that summarizes all technical facts (OFDM modulation parameters, frequency range, interleaving depth, etc), but I won't work on it. You may for example find such a table here: [14]
- If the audio broadcasting template is improved, it should be in the top of the DAB article.
Mange01 08:45, 16 July 2007 (UTC)
- I agree - have removed biased/controversial (indeed duplicate) details from the intro. This article is inded biased - and people continue to make it worse.Chrisp7 09:40, 24 August 2007 (UTC)
- The content of the head of the article has been debated on this talk page at extremely great length, and it has gone through many edits before it has *finally* come to a point where it was stable because people accepted the facts stated and the references that backed up these facts, and you just came along and simply removed it all. You justified your removal of the text by an assertion that it was POV, but it is not POV because the facts all have references and a balanced view is given - i.e. caveats have been added to make sure that the text in the head is fair. 81.107.219.7 11:46, 24 August 2007 (UTC)
- You added additional sections of debatable POV which I removed.
- No, I reverted the intro back to a previous version - I added precisely ZERO characters. I REVERTED other sections where someone else had also deleted sections where they shouldn't have deleted anything. 81.107.219.7 18:31, 24 August 2007 (UTC)
- I am talking about other sections which you changed - why are you changing what everyone else has changed? Why are you the sole person that is correct? All of your changes are 'anti' DAB, cant you see this? Chrisp7 09:53, 25 August 2007 (UTC)
- Secondly the intro to a subject should not be 80% based on criticisms of the subject! The intro should be an introduction into the standard itself. In addition the info is repeated in the main body of the text in the 'controversy' section so why repeat it? The section I removed is purely a repeat of that info. Please justify why it should be in the intro, also please identify yourself, it will make it easier for us all:)Chrisp7 17:44, 24 August 2007 (UTC)
- If you re-read the intro to the page, it is a wholly unbiased and accurate introduction to DAB, because it was originally designed to provide better reception and better audio quality and so forth, which is what the intro says, but unfortunately the way DAB has been implemented by the broadcasters has meant that DAB actually does not provide the things it was originally meant to provide, and that information is important and highly relevant to an introduction to DAB. Therefore, if you want to edit the introduction then discuss it here before you make any changes. 81.107.219.7 18:31, 24 August 2007 (UTC)
- The information in the intro is relevant to DAB and this is represented in the controversy section of the article, I say yet again - its a repeat of what is said there why is this required? Why is criticism of a subject in the introduction? In particular 80% of the intro. This makes no sense, please justify and answer my questions. What you have done is contrary to Mange01 and me and I suspect others - I await their comments and yours. In the meantime I will revert your main body edits and keep the intro to discuss.
- PS Are you Digitalradiotech? Please register, thanks Chrisp7 09:53, 25 August 2007 (UTC)
- Could you state your vested interests in DAB please, thanks. 81.107.219.7 13:48, 25 August 2007 (UTC)
- I have absolutely no vested interest in DAB, I read the article and was rather shocked as to how such a intro could exist on Wiki and I am sure everyone else agree with me. Please do not continue to remove pertinent sentences making POV seem like fact.Chrisp7 14:05, 25 August 2007 (UTC)
Biased, inappropriate and duplicated (from controversy section) introduction? Discuss
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)
- No, this is obviously not biased. 81.107.219.7 13:47, 25 August 2007 (UTC)
- Clever argument there. Please explain why this should be in the introduction and please explain why it isnt biased. Chrisp7 13:59, 25 August 2007 (UTC)
- No, you're the one who has turned up and simply taken it upon himself to delete a large section from the introduction without entering into any discussion first. I have already explained myself at very great length (digitalradiotech) as to why the text in the introduction is justified, and you have yet to provide a single justification for why it is not other than to say that you think it is biased, although you haven't even bothered to say why you think it is biased. Therefore, the onus is on you to explain yourself, not me. If you want to see my justifications just read this Talk page. 81.107.219.7 14:50, 25 August 2007 (UTC)
- Yes I came in and deleted it initially, however after a few edits, I found my efforts futile and decided to leave it in (as I mentioned before) and discuss the issue, which is the whole point of this section of the telk page. Ah so you are digitalradiotech, that all makes sense, why are you the only one editing this article in a biased fashion? No I have mentioned 3 seperate points a) its biased b) Its duplicated and c) It has no place in an introduction. It has a place in the criticism section, fine - but in an introduction it can be deemed as biased. I have placed it in here for discussion, I'd like to hear other people thoughts. In addition please stop deleting sentences from the main vody of the article or I shall have no other choice to report.Chrisp7 17:26, 25 August 2007 (UTC)
- Over the last few days all you have done until now is to simply delete the parts of the introduction that you don't like without discussing it first. And now you have explained what you don't like about the intro, I'm afraid that your justifications don't stand up to scrutiny. (1) your argument that it is biased revolves around you saying it is biased, but you obviously need to explain why it is biased, and provide evidence to prove that it is biased. (2) Of course stuff in the intro is duplicated in the rest of the page, because that's what an intro is for: to provide an introduction to the page. (3) The material about how DAB has actually been implemented does have a legitimate place in the intro, because the intro summarises what DAB is and why it has been developed, but you can't just say that it was designed to provide high audio quality without saying that the way it has actually been implemented by the broadcasters doesn't actually provide higher audio quality. Digitalradiotech 11:45, 26 August 2007 (UTC)
Response to RFC
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)
- Saying things like "proponents say that DAB provides better sound quality" is advertorial. Wikipedia needs to deal in facts, and the facts are that DAB sounds worse than FM, and the facts provided in the intro on this subject are backed up by references. Therefore they should remain in the intro. Digitalradiotech 16:17, 25 August 2007 (UTC)
- Do reliable sources indicate the proponents alleged better sound quality as a reason to use DAB technology? If so, this is worth mentioning in the lead. If there are not reliable sources indicating that proponents alleged improved sound quality, then improved sound quality should not be listed as one of the things proponents claimed is a benefit of DAB. There is nothing advertorial about this, when the very next sentence is "In practice, critics claim," and the list of critical claims that, if true, would negate the reasons proponents had for their advocacy. Where I come from, this is being neutral. What do you believe would be a more fair way to word this introductory summary?
- The current intro is correct on this: one of the main reasons DAB was designed was to provide better sound quality (there's masses of references for this), but in practice the vast majority (we're talking about 98%+ here) of stations in the countries where DAB is being promoted are using bit rate levels that are too low to provide audio quality as good as on FM. This is why the intro is worded as it is, and it has been through numerous edits to get it to the stable state it was at until Chrisp started to simply delete everything on the basis that he doesn't like the facts. Digitalradiotech 17:01, 26 August 2007 (UTC)
- Yet again please justify why 80% of an introduction to a subject should be criticism? Your arguments about the finer details are irrelevant in this case - I repeat why is such a large proportion devoted to criticism?Chrisp7 17:39, 25 August 2007 (UTC)
- This is the only sentence that you don't like: "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]." and that does not account for 80% of the intro. The next long sentence could be deleted for all I care, because it is only there to provide a caveat. The next paragraph is about DAB+, which obviously deserves to be in the introduction and does not constitute criticism as such. Therefore, your assertion that 80% of the intro consists of criticism is false, because there's only actually one sentence that is criticising DAB, and furthermore it is not criticism, it is simply laying down the FACTS. Digitalradiotech 11:49, 26 August 2007 (UTC)
- Also, DAB+ is not under development, DAB+ is an ETSI standard and there are already some receivers in the shops that can be upgraded to support DAB+. Also, describing DAB+ is merely being "more robust" is completely missing the actual advantages that DAB+ brings, which are that it will allow the broadcasters to provide higher audio quality than on DAB and that it will allow far more stations to launch. Digitalradiotech 16:20, 25 August 2007 (UTC)
- I was not familiar with the fact that DAB+ is a standard or with the reasons advocated for its adoption. Would it be correct to change the last paragraph of my proposed new lead to this: "Additional technical standards have been created and standardized under the term DAB+. Although DAB+ re-uses the DAB acronym, existing generation DAB receivers will not be able to receive DAB+ broadcasts. DAB+ proponents cite improved sound quality and ability for more stations to launch as reasons to switch from both FM and DAB to DAB+." Is that accurate? VisitorTalk 15:32, 26 August 2007 (UTC)
- The two main reasons why DAB+ was designed was to allow the broadcasters to provide higher audio quality and to launch more stations, so I don't agree with the use of the word "proponents". Digitalradiotech 17:39, 26 August 2007 (UTC)
- As I have no information about opponents to DAB+, how about this as the last sentence of that paragraph: "DAB+ was designed to provide higher editor quality the ability to launch more stations than possible with either FM or DAB." Is that correct? I don't understand what about DAB+ enables the launch of more stations: does it use less spectrum bandwidth per station? Reduce interference so stations can be closer together? Lower cost to broadcasters of equipping transmitters for the new format? For that matter, should DAB+ be included in the DAB article, or be its own article? VisitorTalk 08:52, 27 August 2007 (UTC)
- VisitorTalk, your intro is far more balanced, unfortunately I feel that too much emphasis is based on criticism of a standard in the intro, however I accept its a lot better and find this to be a happy medium. Chrisp7 17:44, 25 August 2007 (UTC)
- Thanks, I hope to find something that will acceptably give a concise overview for people new to the field, and acknowledge controversy with a neutral point of view. VisitorTalk 15:32, 26 August 2007 (UTC)
- By the way, I have no information about this subject other than this article, and no preconceptions or personal or professional interest either for or against the technical merits and commercial success of the format. I'm simply responding to the request for additional editing help with the article. VisitorTalk 08:52, 27 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)
- VisitorTalk - I fully support your version of the intro. Yoo have found that certain balance that is needed in an article like this. Please, go ahead and change the intro for the better.
- Ga-david.b 10:57, 7 November 2007 (UTC)
Sound quality
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)
- If you're so hell-bent on getting a mention of the criticism as a direct rebuttal of the claims of "good sound quality", why don't you take up my suggestion of combining the two sections into one, rather than repeatedly shoehorning your POV in wherever possible? (which, as you know, is going to get reverted, and get you blocked) Oli Filth(talk) 01:27, 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)
- I suggest removing these sentencens under the cricism:sound qaulity as i find the reference unreliable, as well as a poll on a website would not reveal a reliable opinion among the genereal public:
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 also have to mention that all links to http://www.digitalradiotech.co.uk/ website should be treated with care as long as its more like a personal website. Se http://en.wikipedia.org/wiki/Wikipedia:Reliable_sources/Noticeboard#Is_it_acceptable_to_use_your_own_website_as_a_source.3F fordi discussion. Ga-david.b 10:32, 15 November 2007 (UTC)
- After reading http://en.wikipedia.org/wiki/WP:RS#Self-published_sources, i have decided to remove the sentences in question. Ga-david.b 00:29, 16 November 2007 (UTC)
- Much as I know that Digitalradiotech isn't going to like it, and I can foresee an edit war occurring for the next week or so, I can't disagree with this. Self-citing non-rigorous polls and opinions from self-published material from one's own website is extremely difficult to justify. On the other hand, the links that simply tally up the number of stations at each bit-rate seem harmless enough; I think we can let those slide.
- In terms of the links that have been removed, clearly we should not lose sight of the fact that there is significant criticism of the low bit-rates. If we can find alternative, more suitable sources, then we should do so to avoid unbalancing the article. Oli Filth(talk) 00:57, 16 November 2007 (UTC)
- I certainly agree that bit-rate criticism is important. But there are already a very good reference for this in the intro. The following report is written by PhD. Sverre Holm at the University of Oslo and is very clear on that DAB broadcasts need 160kbps: http://wo.uio.no/as/WebObjects/theses.woa/wa/these?WORKID=52348 Have you read it? Ga-david.b 10:19, 16 November 2007 (UTC)
- I'm unable to read Norwegian, so all I can understand is the "summary in English"! Oli Filth(talk) 13:12, 16 November 2007 (UTC)
- That’s a valid point. Do you believe the summary will suffice? I can testify that it pretty much in line with the whole report. Ga-david.b 14:11, 16 November 2007 (UTC)
- Skimming the rest of the Sverre Holm's report indicates that he says :
- "Hovedpoenget i rapporten er at det ikke er vanskelig å høre problemer med lydkvaliteten ved stereo ved 128 kbps." "The main thrust of the report is that is is not difficult to hear problems with the sound quality in stereo at 128 kbps"
- "Det ble så spurt om hvordan det kan ha seg at et system som engang ble markedsført som å ha ’nær-CD’ kvalitet, i dag har dårligere lydkvalitet enn god FM stereo på noen av sine musikkanaler. Her baserte rapporten seg på det som er publisert i åpen litteratur og pekte på den store forskjellen mellom de engang anbefalte bitratene (192-256 kbps) og de som brukes i dag (128-192 kbps)" "...marketed as 'near-CD' quality, today has worse sound quality than a good FM stereo...open literature indicates the large difference between the recommended bit-rates (192-256 kbps) and those used today (128-192 kbps)"
- "More demanding material should have the same quality as mp3 at 128 kbps, i.e. 192 kbps in DAB."
- ...I think it supports the contention that replacement of stereo FM with DAB should be at bit rates above 128 kbit/s with current codecs. WLDtalk|edits 16:06, 16 November 2007 (UTC)
- Skimming the rest of the Sverre Holm's report indicates that he says :
- I guess this is suitable! Nevertheless, if we can find a full English-language source at some point, it would probably be preferable. Oli Filth(talk) 20:23, 16 November 2007 (UTC)
- I agree. On the other hand, i have been asking myself if the whole issue about bitrates really are such a big issue. I mean; most of the information aboute the "DAB sounds worse than FM" have been written by DigitalRadioTech in different forums and such. I also see that most DAB listeners are more satisfied with their DAB radio than their FM radio (Ofcom measured a satisfaction level above 90%, wich is quite outstanding results). Therefore i have a tiny hunch that the whole bitrate aspect is being based on more noise than facts. However, I’m more than happy to write about it, as I really wish for more bandwidth for DAB in Norway, where i live, and the bitrate talk is really helpful in regards to lobbyism efforts over here. Ga-david.b (talk) 11:32, 17 November 2007 (UTC)
Split section proposal
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 agree with you on a split, mostly because the article is to long. However, the current article should shortly mention the number of countries using Eureka 147. A tiny paragrahp could do. The new map could company both articles Ga-david.b 08:14, 15 November 2007 (UTC)
- I've now created the new article: Regional implementations of DAB. I'll work on a short summary paragraph to fill the left-over section stub soon. (Feel free to do this yourself if you feel like it!) Oli Filth(talk) 12:51, 17 November 2007 (UTC)
Changes to lead (and others!)
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)
- P.S. I've just realised that the link to WP:UNDUE above doesn't really fit what I'm describing, but a similar principle applies. The lead should summarise the most important points of the article, preferably in an order that best reflects their importance, so that an ::::::::::::extremely casual reader can get some grasp of the issues just by reading the lead. Oli Filth(talk) 20:00, 16 November 2007 (UTC)
- I think both DAB, DAB+ (and also DMB, as they are all sibling technologies) should be summarized in the intro. They are all major standards, and being used every day. However, details, speuclations and technicalites should be kept out of the intro. (And by the way - most people who are going to use DAB+ would ver likely know the technology by the name DAB, so this makes it even more important to be strict about the amount of DAB+ speak Ga-david.b (talk) 11:04, 17 November 2007 (UTC)
- I'm not disputing that DAB+ should be summarised, simply that it's not the most important aspect of the article, and as such, shouldn't be placed first in the lead. Oli Filth(talk) 12:37, 17 November 2007 (UTC)
- Australian people would beg to differ, as they won't be using DAB at all, only DAB+. Digitalradiotech (talk) 15:43, 17 November 2007 (UTC)
- I expect a few readers to enter this wikipedia article after searching for the phrase DAB+ or even DMB, as they are somehow a buzzword these days, depending on where you might be located of course. However, no one would expect to read all the details about when or what radios supporting DAB in the intro. Heres a suggestion for an appropriate intro mentioning of DAB+:
DAB comes in several versions; the more common DAB, as well as the newly established DAB+, or the multimedia oriented DMB and DAB-IP.
- Oh, and one more thing -- according to the history section, DAB were developed during the eighties and ninethies. Ga-david.b (talk) 23:00, 17 November 2007 (UTC)
- DAB+ is a **major** development, and it is not backwardly compatible with DAB, and some countries will only use DAB+, and other countries will be adopting DAB+ in 2008/9, so if you think that the only mention DAB+ deserves in the intro is "as well as the newly established DAB+" then you are very sadly mistaken. For example, this is an English language version of Wikipedia, and Australian people speak English, and they will ONLY be using DAB+. In addition, the reference I provided that said that DAB+ will be used in the UK in the next few years was published by the DRDB, which is UK DAB's marketing arm, and is funded by the BBC and the biggest commercial radio broadcasters.
- The problem with the reference is that it is not traceable. It is not signed by anyone, and i can not find anything that verifies the content of it. On the other hand, the very same document had a reference to anothe document at world dmb forum that said that the UK will continue to use the establisehd DAB-version. And i also found another document confirming that there are no plans to allow DAB+ in the UK for quite a while. (http://www.which.co.uk/reports_and_campaigns/audio_visual/reports/audio/hi_fi_and_radio/Digital%20radios/digital_radios_essential_guide_574_66696_10.jsp). If you can find a reference outside your own website that says the opposite, i will be happy to change this.
- The document was published by the Digital Radio Development Bureau (DRDB) in January 2007, and the DRDB is wholly funded by the BBC and the biggest commercial radio broadcasters in the UK. If you don't believe me, then email the DRDB to ask them about it. Which? magazine, on the other hand, is not an expert source of information about DAB+, so information they provide doesn't carry any weight. And I repeat what I said last time: you know perfectly well that DAB+ stations will launch in the UK in the next few years - EVERYBODY with an interest in DAB knows this - so trying to claim that DAB+ won't be used in the UK is extremely dishonest. Digitalradiotech (talk) 11:22, 19 November 2007 (UTC)
- I am not in a situatiuon where I’m able to get your document verified, and if you are not able to verify it by an other means, you have a less credible reference, and should remove it or replace it.
- I am submitting your reference for wikiepedia review to get a second opinion on it.
- Just because something isn't available on the Internet other than on my website does not mean that this document isn't legitimate. Digitalradiotech (talk) 17:52, 19 November 2007 (UTC)
- That’s right, but you are the one that have exeptional claims and therefore it is your job to back up your exeptional claims with exeptionally credible evidence. I have provided you with two far more credible sourcese claiming the exact opposite of what you have written, and therefor it is a duty for me to remove your unverified claim. Ga-david.b (talk) 20:08, 19 November 2007 (UTC)
- I am not making "exceptional claims" at all. Have a read of this article: [15] in particular this quote: "Manufacturers are now building support for DAB+ into new receiver models in the expectation that this will be the common standard for sound-oriented services in the future." - and here's the Ofcom document from which that quote is from: [16]. If I wanted to link to that Ofcom document would you rule it out because it's not available anywhere else on the Internet?? There is ABSOLUTELY NO DOUBT that DAB+ will be used in the UK in the next few years. End of story. Digitalradiotech (talk) 20:57, 19 November 2007 (UTC)
- Once again you are refering your own website. Havent you learned anything?
- Explain to me what is wrong with my website hosting that document. Digitalradiotech (talk) 23:38, 19 November 2007 (UTC)
- Hey, I’m not the problem here. But you are breaching the wikipedia guide lines. Please read this: http://en.wikipedia.org/wiki/Wikipedia:Verifiability#Self-published_sources_.28online_and_paper.29 - then discuss with Wikipedia administrators if you believe that this rule should not apply to you. Ga-david.b (talk) 23:56, 19 November 2007 (UTC)
- As I've already tried to explain to you, my website is merely hosting that document, therefore the self-published sources rule doesn't apply, and I would be happy to discuss this with a Wikipedia admin. Digitalradiotech (talk) 12:39, 20 November 2007 (UTC)
- I certainly agree that DAB+ is a huge leap forward, but most people are interested in DAB in general (after all they are reading the DAB article after looking for info on DAB), and those who are interested in DAB+ will be reading the whole section dedicated to DAB+.
- Have a look at the pages for Microsoft Windows and Mac OS - these operating systems exists with a tremendeous amount of versions, but the articles have dedicated whole sections to the several versions (See http://en.wikipedia.org/wiki/Windows and http://en.wikipedia.org/wiki/Mac_os for what i find more readable.) Ga-david.b (talk) 10:51, 19 November 2007 (UTC)
- Also, EVERYBODY that has an interest in DAB knows full well that DAB+ will be used in the UK in the next few years, so attempting to use a reference to say that it won't be used is highly dishonest. You claim that you don't work for NRK or any of the other organisations involved with DAB in Norway, and yet you seem to do exactly what I would expect someone from those organisations would do - which is to cover up the truth about DAB+ so that people continue to go out and buy DAB radios that will be obsolete in the next few years. You have never provided a shred of evidence to support the fact that you don't work in the Norwegian DAB industry, and yet I'm consistently accused of being biased due to the fact that I run the digitalradiotech.co.uk website. So I think it's about time that you provided some proof of who you are, what you work as, and who you work for. Digitalradiotech (talk) 10:12, 19 November 2007 (UTC)
- Even if i where working for NRK or anything DAB related (wich i am not), that would not disqulify me from writing on this article as the wikipedia guidelines demands proper references for all my claims. Of course i have my opininon on DAB, just like you have, and that is why we need to agree on what we could write as a fact, and preferably we could both back up our claims with sources.
- Remember, you should be able to be better than me about providing references, since you have been writing about DAB for quite a while. Ga-david.b (talk) 10:51, 19 November 2007 (UTC)
- I'm not saying that you should not be able to edit the page. What I'm saying is that my identity is known and the website I run is known, whereas you are trying to pass yourself off as being a member of the public, when in reality it's obvious that you work in the Norwegian DAB industry, so it would be fair to admit this. Digitalradiotech (talk) 11:22, 19 November 2007 (UTC)
- I’m very sorry, but I do not work in the DAB industry.
- But my position and workplace is relevant. You MUST start referencing your claims. If I understand you correctly, it should be quite esay since "everybody knows" means that you can get someone to post a confirmation somewhere.
- If you are removing cited and referenced material, you can only do so it if
- 1) the reference is not credible (then you should point out why it is not credible here, and the we can go through the referenced material togeheter)
- 2) you have a better source of information that gives us better insight
- Anyhow - i have gone back to my good fait edit, and you can’t simply revert it without a reason. Ga-david.b (talk) 17:02, 19 November 2007 (UTC)
- Then you need to show that I'm not credible, or else you leave the cited reference to the DRDB's document alone. But bear in mind that if you say I'm not credible, that is libel, and I will sue your sorry ass.
- Of course you are not credible. No one are - that is why Wikipedia demands credible sources from everyone. Even if you were God almighty, people like me would demand a credible source for any claim. Ga-david.b (talk) 20:08, 19 November 2007 (UTC)
- If I'm not credible, why did 2 Norwegian national newspapers pay me to write articles about DAB for them? I'm sure you remember those, don't you, as you're a member of the Norwegian DAB industry. Digitalradiotech (talk) 21:00, 19 November 2007 (UTC)
- You need to have this argument with the wikipedia administrators as they have written http://en.wikipedia.org/wiki/WP:RS - Please read it.
- Now i would appreciate if you found a credible source from somewhere else than your personal website. Ga-david.b (talk) 23:23, 19 November 2007 (UTC)
- I'll say this slowly: my website is merely HOSTING the document. Digitalradiotech (talk) 23:35, 19 November 2007 (UTC)
- And as you agree that your position and workplace are relevant, could you say what your position and workplace are please? Thanks awfully. Digitalradiotech (talk) 17:52, 19 November 2007 (UTC)
- Since it is not important (and since i know how you write unpleasent carateristics about people on your website) i prefer to not reveal anything about myself. Instead, i prefer to back up my claims with credible sources, something you should do as well Ga-david.b (talk) 20:08, 19 November 2007 (UTC)
- I TELL THE TRUTH on my website, and if that means accusing people who have lied of being liars then so be it, and they simply shouldn't have lied in the first place. Digitalradiotech (talk) 21:00, 19 November 2007 (UTC)
- Please stick to the point and come up with a credible source for your claims or simply remove them. Ga-david.b (talk) 23:23, 19 November 2007 (UTC)
- My website is merely HOSTING the document. Digitalradiotech (talk) 23:35, 19 November 2007 (UTC)
Audio codec
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).
- It's simple to sort that one out - I'll just delete the word "arguable the" and put in "one of" instead... Digitalradiotech (talk) 15:08, 17 November 2007 (UTC)
- I believe your edit only made the paragraph go from bad to worse. Simply remove it as it is only speculation. The principle for inclusion in Wikipedia is very easy: If you can’t find anyone supporting your claim, then it’s probably not worth mentioning in this article. Ga-david.b (talk) 23:12, 17 November 2007 (UTC)
- You also deleted an ENTIRE paragraph on the basis of the use of the word "arguable". If I had done the same you would presumably mark my edit as being "vandalism". Digitalradiotech (talk) 15:10, 17 November 2007 (UTC)
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)
- I've put "arguably" in, so what on earth is your problem??? My reason for saying this is that changing from say vanilla OFDM to a slightly better form of OFDM, like the Chinese have done for their DTT system, gains you about 10-15% capacity. Changing error correction coding from convolutional to convolutional + RS coding adds about 20-30% capacity with all else being equal, and changing to turbo or LDPC coding might add another 10-15% on top of that. In comparison to those small improvements in capacity, the switch from MP2 to AAC+ has provided a 200% increase in efficiency in one fell swoop AND in future you can't rule out some new AAC++++ codec being designed that could say provide another doubling of the effective capacity of the system, whereas the OFDM and FEC side of things have very limited potential to increase the cpacity, as I've said.
- Probably the most important thing to the broadcasters at the moment is the transmission costs per station, because they're spending a fortune simulcasting on digital and analogue, and they're going to have to continue this until FM is switched off. And if you think this is some irrelevant fact, GCap Media spends something like £11m per year on digital transmission costs, which is about twice as much as it spends on analogue. And using AAC+ will result in them being able to slash their digital transmission costs. For example, if they chose to use the same level of audio quality (they won't, but just suppose), they would reduce their DAB transmission costs by a factor of 3. A third of £11m is a lot of money, and if you don't think it is then don't give up your day job to become an accountant. Digitalradiotech (talk) 15:10, 17 November 2007 (UTC)
- The problem with the word "arguably" is that absolutely anything is arguable. Have you had a chance to read WP:AWW yet? Oli Filth(talk) 15:19, 17 November 2007 (UTC)
- As I've removed the word "arguably", I can't be bothered to read the page you mention. Digitalradiotech (talk) 15:45, 17 November 2007 (UTC)
- If you're going to edit this page regurlarly, you probably should read some of the editing guidelines and policies, especially ones that people point you towards in discussions such as this. This isn't your website, where you're to free to put whatever you like. The Wiki editing policies (which you charmingly refer to as "pedantry") exist for a reason. If you choose to ignore them (or stay ignorant of them), then you only have yourself to blame for the resistance you experience to your edits (or in extreme cases, finding yourself being blocked). Oli Filth(talk) 15:50, 17 November 2007 (UTC)
- As for the technical arguments; as an example, moving from DQPSK to QPSK (for example) gives an instant reduction (like 10 times) in raw BER for a given SNR in a flat channel. Of course, the channel isn't flat, but combined with equalisation, one could get damn close. And of course, with equalisation, one could theoretically move to 16-QAM or higher (yes, I know this would increase the BER). Take DVB for example, also an OFDM system at heart, and achieves a spectral efficiency > 2 bit/s/Hz. This compared to DAB, at < 1 bit/s/Hz. (I'm aware this isn't necessarily a fair comparison, as I haven't compared the typical BER, which I don't have to hand). My point is/was that there's plenty of scope for improvement at the physical layer alone. Oli Filth(talk) 15:49, 17 November 2007 (UTC)
- I'm not saying there isn't massive scope to increase the spectral efficiency of DAB's modulation scheme, but even on mobile broadcacsting systems that can use 16-QAM, such as DVB-H, QPSK is typically used because the quadrupling of power needed to go from QPSK to 16-QAM doesn't stack up in ecomomical terms, because you only double the capacity, so it's cheaper per bit to use QPSK - there's a rule of thumb that transmission costs are linearly related to transmission power.
- Also, I'd argue that WiMAX simply would not use 16-QAM or 64-QAM if it used a weak error correction coding scheme, such as convolutional coding. Another example is HSDPA, which is using 16-QAM and higher(?), but it's able to do so because it's using turbo coding.
- The design of DVB-H is a good example of stronger error correction coding enabling the use of 16-QAM, because when they started looking into it they first used the DVB-T system and tried to receive that when travelling at high speed, but they found that the only way to feasibly receive a DVB-T signal reliably at high speed was to use antenna diversity (2 antennas at the receiver). But they wanted to receive a signal on handheld devices, so they added the MPE-FEC, which is a powerful 0.75 code rate RS code as a third layer of error correction coding, with the inner layers being an EEP convolutinoal code and a 188/204 code rate RS code (the inner 2 layers are almost identical to what's been adopted for DAB+). For example, here's a quote from the DVB-H Validation Task Force Report[17], page 7:
- "Thanks to the MPE-FEC, the DVB-H transmission performance, assessed both in the laboratory and in the field, offers a similar improvement in C/N performance to that obtained in DVB-T receivers using antenna diversity (6 dB to 9 dB)."
- So it's the error correction coding that enables the use of higher order signal constellations, which is why I consider it to be more important than modulation. Digitalradiotech (talk) 16:57, 17 November 2007 (UTC)
Error correction coding is more important than OFDM
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.
- I'm not saying it's more important, I'm saying it naturally falls under the higher-level heading of "transmission". If you like, we can put the stuff that's current under "transmission" under the sub-heading "modulation scheme", and then swap the order with "ECC", but both still under the "transmission" heading.
- Okay. But FEC goes above OFDM. Digitalradiotech (talk) 15:42, 17 November 2007 (UTC)
- As an aside, of course the choice of modulation scheme is important; the choice of OFDM makes the received signal particularly easy to equalise, or in the case of DAB, removes the need for equalisation entirely (as DQPSK is being used). I'm not however, going to attempt to offer an opinion on which is more important. Oli Filth(talk) 15:12, 17 November 2007 (UTC)
- I haven't said that OFDM is unimportant, I'm merely saying that FEC coding is more important than it as far as a digital radio system is concerned because which kind of FEC coding and what code rate level is used has a major effect on the reception quality. Digitalradiotech (talk) 15:42, 17 November 2007 (UTC)
ECC in DAB+
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)
- You're right, DAB+ doesn't use Forney interleaving, it uses a rectangular interleaver. Digitalradiotech (talk) 14:23, 18 November 2007 (UTC)
OSI stack
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.
- I'm happy to remove mention of the OSI model, as it's outdated, and stick to talking about FEC as part of the PHY. Although the DAB spec makes no distinction between stack layers (probably because it's a broadcast protocol), any other wireless spec (e.g. GSM, UMTS, HSDPA, 802.11, 802.16) puts FEC in the PHY. Oli Filth(talk) 14:27, 18 November 2007 (UTC)
DAB+ in the intro
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.
- Of course it's not okay. You've deleted the link to the document that's hosted on my website purely because it contains the fact that the UK will be launching DAB+ stations in the next few years, which is information that you're trying to hide, and you're also trying to hide the fact that existing DAB receivers cannot receive DAB+ stations. This is all information you're trying to hide because you work in the Norwegian DAB industry, and you don't want consumers to know the truth about DAB+. Digitalradiotech (talk) 12:59, 20 November 2007 (UTC)
- It is very sad that you are unwilling to find a solution.
- I've already made compromises in order to allow the intro to become stable, but you then came along and simply deleted a whole paragraph and replaced it with 2 or 3 lines and of course failing to mention facts that you want to hide from people. So it is you that is refusing to find a solution here, but the problem is you can't bring yourself to allow the truth to be told - hence why you have to resort to accusing me of writing the document that was in reality written by the DRDB, but you know that anyway. Digitalradiotech (talk) 16:07, 20 November 2007 (UTC)
- BTW, if you read what I wrote in my edit of 12:59 above you will see that I said precisely what information I am saying should be left in the intro, so I obviously am willing to find a solution. Digitalradiotech (talk) 16:27, 20 November 2007 (UTC)
- Please link to the diff where Oli filth came to an agreement with you. Ga-david.b (talk) 15:35, 20 November 2007 (UTC)
- Just look at how many edits and how much work we did on Saturday and Sunday, and yet the intro remained stable. This is how it should have stayed, but of course you won't allow people to know the truth about DAB+, so you had to continually revert it. Digitalradiotech (talk) 16:07, 20 November 2007 (UTC)
- In other words: you can not come up with a diff showing where you have come to an agremenet on the intro? Ga-david.b (talk) 22:28, 22 November 2007 (UTC)
195.159.3.166 (aka Ga-david.b)/MP2 tolerance for errors and Norwegian topography
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+.
- If my understanding is wrong, please let me know!
- If I'm correct, it looks like 195.159.3.166, which is likely Ga-david.b has a misunderstanding. If not, it would be useful if they could have cited what makes this rather odd statement about MP2 encoding and Norwegian topography correct. DAB using MP2 might be better than a theoretical DAB using AAC+, but DAB+ is AAC+ plus Reed-Solomon, which changes things somewhat.
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,
WLDtalk|edits 18:32, 20 November 2007 (UTC)
- Hi, yes i did add that a while ago. I have references in the written edition of Teknisk ukeblad, and i will provide it on the norwegian talk pages (I have to do it tomorrow as they are not a home). However, i might be wrong on this, or teknisk ukeblad can be wrong, so i welcome both a closer look, a possible rewrite and even more citations:) See you on the talk-pages! :) —Preceding unsigned comment added by Ga-david.b (talk • contribs) 22:33, 22 November 2007 (UTC)
- Yes, Ga-david is wrong. Have a read of the: | MP2 Robustness Myth sub-section. Topography is completely irrelevant. Try the | audio codec error simulator program I've written with some MP2 and AAC+ files (MPEG-4 AAC+ files that you've encoded yourself might not play back though due to CRC checks failing because files on a home computer are expected not to have errors) - there's some MP2 and MPEG-2 AAC+ files with and without errors added available to download from the | MP2 Robustness Myth sub-section as well.
- My program disproves that MP2 has a greater tolerance to errors than AAC+ (or any other audio codec), because for a specified BER (bit error rate) the program adds the appropriate number of errors purely at random, and although it's some time since I had a play with the program, my recollection was that MP2 is actually less tolerant of errors than the other audio formats.
- The other issue is how MP2 performs with the FEC coding on DAB and how AAC+ performs with the FEC coding on DAB+, and page 11 of the | WorldDMB DAB+ brochure shows that the combination of AAC+ with convolutional + RS coding is more robust to errors than MP2 with UEP convolutional coding.
- Page 8 also shows that tests have found that 40 kbps AAC+ provides similar or better audio quality to 128 kbps MP2 - just in case he disputes that DAB+ is 3 times more efficient than DAB. In actual fact, the gain in efficiency is greater than 128/40, because with DAB+ being more robust than DAB then a fair comparison of efficiency would set the robustness of the audio to be equal on both DAB and DAB+, so DAB+ would actually be closer to 3.5 - 4 times more efficient than DAB is. Digitalradiotech (talk) 11:50, 21 November 2007 (UTC)
Non neutral biased article
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)
A few issues need work.
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.
- It is factually accurate - why do you have a problem with it?
- Because it's not true that 98% of stations in Denmark, Norway, and Switzerland use 128kbps. -RC
- Fair enough, I'll change that. Digitalradiotech (talk) 07:51, 29 April 2008 (UTC)
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.
- Too low to provide good audio quality. 128 kbps provides poor audio quality. Digitalradiotech (talk) 20:30, 28 April 2008 (UTC)
- Poor is relative, and audio codec quality is completely subjective. -RC
- I've said worse than FM in the article. Digitalradiotech (talk) 07:51, 29 April 2008 (UTC)
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".
- See bottom of page 11 of this: [20] Digitalradiotech (talk) 20:30, 28 April 2008 (UTC)
- I saw it. It a blatant lie by omission. That paper cites [21], which itself says only at very low bitrates is it 3X. Furthermore, read the two sources I cited in the article, which give a very different estimate. -RC
- I've already changed this anyway. Digitalradiotech (talk) 07:51, 29 April 2008 (UTC)
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...
- It says "one of the most important", so I fail to see why you've got a problem with this. Furthermore, the choice of which audio codec to use on a digital radio system is without question a very important design decision - use the wrong audio codec and you end up in the mess the UK is now in - use the right codec and you don't end up in a mess.
- I'm going to edit the longer introduction where you have issues with it. If you have any further issues with the introduction, then discuss them on here first - please don't rever the whole lot, because it'll just end up in an edit war. These things are avoidable if people are reasonable. Digitalradiotech (talk) 20:30, 28 April 2008 (UTC)
- Ironic. So far, you're the only one who has shown a tendency to ownership and edit waring. I must decline your ultimatum. Here's a better one... BEFORE you revert ALL my changes (fully supported by citations) you'd better have a very good reason to do so. The fact that my changes weren't approved by you does not count. -RC Rcooley (talk) 00:46, 29 April 2008 (UTC)
- So you're accusing me of showing a tendency to ownership and then just a few words later you say "BEFORE you revert ALL my changes (fully supported by citations) you'd better have a very good reason to do so."?? You don't own this page any more than I do. I'll edit the things I've said I will above now. Digitalradiotech (talk) 07:51, 29 April 2008 (UTC)
- Removing well-supported and CITED content is vandalism. This is precisely what you continue to do. I did not tell you that you couldn't make any changes to the article. You, however, have repeatedly done exactly that by repeatedly reverting all my factually correct and cited changes. Your minor changes have helped little. The article remains extensively factually inaccurate. Rcooley (talk) 22:11, 29 April 2008 (UTC)
- Funny how you thought "removing cited content" was acceptable behavior when you did it to the HD Radio article. You criticize Digitalradiotech for vandalism, and then you turn-around and do the exact same thing over in HDR. Ironic. (Point: Do not delete several paragraphs of CITED information from HDR.) ---- Theaveng (talk) 11:52, 30 April 2008 (UTC)
- It all looks to be sorted out now, see [22] and [23]. Digitalradiotech (talk) 15:21, 30 April 2008 (UTC)
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)
- No responses in over 3 weeks. Consensus of one! Done, on all counts. Now it's all over but the shouting. Rcooley (talk) 21:52, 23 April 2008 (UTC)
Keep your debate out of HD RADIO article (pointing at rcooley)
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)
Changes made to intro
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)
- I think the article is improved, thank you. There are a few places that could perhaps do with a bit more work or expert knowledge on the subject.
- For instance, there is a section talking about BBC radio and bit rates for various channels, most notably BBC3. It ends with saying the bitrate was reduced to 160, but someday they might increase it back to 192. One gets the impression that being the government they will simply leave it at 160 forever and hope everyone forgets it once sounded better.
- Next there is a section on German DAB, talking about how they are more interested in money than quality, with the exception of BBC3 which had gone back to 192 kbits after complaints. I'm left thinking: BBC in Germany? Is it running at a higher rate than BBC in England? Did this sentence really belong in the previous section?
- The sections may be completely accurate as stated, but if so a little explanatory text to eliminate the sorts of confusion I illustrate above would be useful. When did the BBC lower BBC3? When did they say they would raise it? Did they ever do it? Is this really BBC3 in Germany we are talking about in the next section? What is the normal German bitrate? 128? 64?
- The front of the article gives the impression (at least to me) that DAB is in use and has been accepted for "many years" and has quite deep penetration compared to analogue radio, even though I don't recall seeing any penetration figures. Yet farther down the article there is a sentence stating poor acceptance because DAB is "quite new" or words to that effect. Some confusion could be eliminated by separating out when it was designed, when it became a government spec, when broadcasting equipment was installed (in various locations, since it probably differs), and whether in fact it is more than a few experimenters that are listening to it.
- One final thought. When I first tripped over this article I assumed that it was a summary article on Digital Audio Broadcasting techniques, of which they are several. I was quite surprised to discover it was describing a very specific European version that had apparently trademarked a generic term. If there is a generic artice on the subject, it would be worthwhile to have a redirection at the top of the page to point out the location of the more generic article.
DAB+ characteristics
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)
DAB versus DAB+ in Ireland
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)
Slimline DAB radios with IPOD docks- do they exist?
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)
DAB+ in Hungary
"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)
RfC: Is this article biased?
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)
DAB+ in Hungary
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)
Something is very wrong with this article
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)
- Where is the justification for the claim of bias? simply stating that a source is biased doesn't make it so. I could claim that the above text shows bias (in favour of low bitrate DAB, possibly from within the pro-DAB lobby.) The fact that the editor is anonymous doesn't help his case. However, I won't revert the edit at this time.
- Anybody who thinks 160k MP2 sounds as good as high quality FM from a hifi tuner needs to get their hearing checked out. --Ef80 (talk) 19:11, 3 December 2009 (UTC)
- It is easy to see that www.digitalradiotech.co.uk - just look at the banner, where it says "Join the Save FM Campaign". This website must be said to have a very concrete agenda, hence all the anti-DAB propaganda. DAB is a transmission and this Wikipedia article should point towards it advantages and disadvantages, and not be a part of a pro og anti-DAB propaganda campaign.
- I prefer DAB (and look forward to DAB+) radio for my kitchen radion simply because I live in an area with limited FM broadcasts with lots of noise. As most people i have an opinion, but i have no intention on brainwashing people at wikipedia. If this places me in the pro-DAB lobby, so be it :)
- I have now rewritten the intro to reflect both positive and negative aspects of DAB.
- BTW: the quote on 160kbits equals FM is from the sourced material in the article84.48.121.23 (talk) 13:24, 8 December 2009 (UTC)
- Your edits are highly biased. I have reverted to an unbiased edit to remove your pro-DAB bias.
- My edits are well referenced by published articles as well as statistics, and I can’t understand how you can find this kind of information for biased.
- Please elaborate, so i can understand your concerns. 84.48.121.23 (talk) 10:14, 11 December 2009 (UTC)
- I still can’t see you discussing your problem with the source i have been using, and how we should be able to display both sides of the sound quality argument. That’s to bad. Segrov (talk) 00:47, 19 December 2009 (UTC)
UK bitrate decisions
The Sound Quality section contains the following odd statement:
- The UK Government seeks to maximize licence-revenue from the available spectrum. Therefore it ‘squeezes in’ as many stations as possible.
- ‘Squeezing in’ techniques include:
- * Minimizing the bit-rate, to the lowest level of sound-quality that listeners are willing to tolerate. :This is generally 128 kbit/s for stereo and 80 kbit/s or even 64 kbit/s for mono, although with these mono low :rates acceptable quality is achieved with speech only.
- * Having few digital channels broadcasting in stereo.
- These factors reduce sound-quality to the point where it is technically inferior to FM.
- Maximizing Government license-revenue is not such an priority with TV, so BBC TV audio streams use a bit-rate of 256 kbit/s MP2.
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)
- Yes, i agree. I tried to ease the text a little bit. Feel free to improve, as my english is far from perfect. Also, some links are outdated. Segrov (talk) 00:04, 14 December 2009 (UTC)
- ^ [http://technology.guardian.co.uk/online/insideit/story/0,,1948524,00.html Guardian article
- ^ http://www.david.robinson.org/commsbill/#1_2_3
- ^ http://bildr.no/view/48137
- ^ http://wo.uio.no/as/WebObjects/theses.woa/wa/these?WORKID=52348
- ^ http://wo.uio.no/as/WebObjects/theses.woa/wa/these?WORKID=52348
- ^ http://www.radionytt.no/kommentar0705.htm