A discussion on digital radio technology

You say RTE are doing DAB NOW, but they're not, they're testing DAB, so both of us are talking about things in the future.

Anyway, I don't see what your point is, because by the time Ireland starts a commercial DAB service DABv2 receivers WILL be available in the shops -- probably in UK shops and selling well.

You said that it would take TEN YEARS to get new receivers in the shops. Look at DVB-H, the standard was only released last year and yet, if I remember correctly, Nokia, Samsung and LG are all releasing DVB-H mobile phones in the next few months and Crown Castle are starting rolling-out DVB-H commercial services to 30 American cities starting in a few months' time and there's 2 commercial DVB-H launches in Italy starting this year.

And DVB-H will have required quite a lot of experimentation to get the time-slicing right, because that's totally new technology to the standard.

Compare that with DABv2: as I seem to have had to say hundreds of times on this thread so far, DMB is virtually identical to DABv2 and both the main DAB module designers (they account for about 95%+ of all DAB modules) have already released DMB modules, so the software IS EFFECTIVELY DONE.

And I repeat again: Radioscape's modules are all pin-compatible, so it is literally simply a case of loading new software onto an EXISTING module and putting that into an EXISTING radio -- e.g. Roberts' DAB radios all use Radioscape modules, so all they need to become DABv2-enabled is new software loaded into them.

Look at the differences between DABv1 and v2:

* new AAC/AAC+ audio codecs
* new RS FEC coding

Both of these are already present in DMB, so Radioscape and Frontier-Silicon have already written the software.

What on earth would take so long to change?????

david23 wrote:

There seems to be some confusion here. In this article RTE's head of operations says "this could very soon be all over the country". He goes on to talk about DAB-only content being launched on the multiplex in September 2006, so it doesn't appear from this that they will be pulling the plug after 3 months. Have you read something different?

I think I've read that they're currently test transmissions, and I think I've seen people say that on here as well. Is that wrong?

But if Ireland is now transmitting DABv1 forever, you have my very deepest sympathy, because Ireland -- like the UK -- won't be able to receive high audio quality on digital radio, which is obviously a great shame for the Irish public.

MYOB wrote:

Lack of interest from radio makers, because nobody is going to be transmitting compatible signals. Why bother paying an extra licence fee and using no doubt more expensive decoder modules (as well as having to change your own software to support it) when theres nothing to listen to?

DVB-H was defined in the original (1994) DVB-COOK as far as I can remember, I would have to check the physical document, but I seem to remember it being there. Thats 11 years to testing, 12 to public access.

And as someone else has said, RTE intend to be fully operational and out of testing by the end of this year. There will not be any DABv2 receivers available by then, simple as that.

Then you have my deepest sympathy, because DAB at bit rates below 224kbps sounds very poor, and at 128kbps, like we have in the UK and which you will end up with, it sounds abysmal.

And, no, DVB-H was not defined in 1994. DVB-H is a new system that resulted from work on testing the feasibility of using DVB-T when mobile, which started in 2000 with the MOTIVATE project. It was found that mobile DVB-T required diversity reception to work well at lowish SNR, so they decided to design DVB-H with one of the main objectives to solve the diversity reception issue, which they did by adding the MPE-FEC.

Actually, looking at the DVB-H specification (ETSI EN 302 304) it was released in June 2004, so it wasn't last year as I originally said. But Nokia has their 7700 mobile phone with DVB-H available by about summer last year, which is about 1 year after the spec was ratified. The spec hadn't been passed by the ITU though.

MYOB wrote:

Once again, patronising isn't needed

Its been a long time since I read the DVB-COOK so I was unsure. However, new standards occasionally get jumped on by manufacturers before release - 802.11g wireless was, as is 802.11n wireless now. However, when a format has almost total lack of interest from the end-use manufactuers - in this case, the people who make the radios, Roberts, etc - its going to languish as a never-adopted format, or at best make a few minor appearances.

I seem to remember Ofcom pushing like crazy for DMAC and HD-MAC to be the UK's satellite formats? Did anything come of it? A bankrupt satellite company, and that was that.

Once again, I wasn't patronising.

And I don't see what point you're trying to make about 802.11n, i.e. the pre-n stuff. What relevance has that got to DAB or DVB-H?

And I somehow doubt Ofcom were pushing DMAC or HD-MAC like crazy, seeing as Ofcom is only about 2 years old.

MYOB wrote:

I don't see being provided with a service which our licence fee has already paid for as being short changed. As I said, if a worthy sucessor ever gets off the ground, it will be replaced. And we'll have actually had something in the interim, rather than waiting and waiting and waiting; which is what you seem to think is the ideal option

Yes, you are obviously being short-changed if you're going to be stuck with a digital radio system that WILL NOT provide audio quality that comes close to matching FM.

At the end of the day, if a digital radio system that is meant to be a successor cannot match the audio quality of the preceding system then whichever public service broadcaster adopts it is obviously short-changing its listeners.

And as for you ending up with DABv2 like all the other countries, don't you realise that what you're saying you want is to receive low audio quality for about 10 years while all the other countries wait a few months and get high audio quality from when their service begins.

But hey, if that's what you want...

MYOB wrote:

Namely that if a pre-standardised technology is good enough to be used, it will get used before the IEEE/ITU/whoever actually standardises it. I don't see any DABv2 kit out on the market, do you? How long since its first draft was written?

You obviously don't pay any attention to what I write then, because as I've said on numerous occasions, DABv2 is virtually identical to DMB, and DMB is already operational in South Korea and is currently testing in the UK.

s/Ofcom/whoever was in charge of satellite back then. Cable Authority or similar. Predecessor of Ofcom. Either way, the UK governmental agency with responsibility for direct broadcast satellite systems initially -required- any licence takers to be able to use DMAC transmission, with an option of HDMAC for HDTV. BSB did use DMAC but it flopped. Now they're recommending that people support DABv2, which isn't even in public use yet... history repeats itself.

History repeats itself? Erm, if DABv2 never sees the light of day then you'd be right. Unfortunately, DABv2 will see the light of day and receivers WILL be made for it and countries will adopt it -- why on earth would they adopt DABv1 when DABv2 is available??

digitalradiotec wrote:

Is there some important news that I've left off my website? If there is, please let me know. I've written an article about Ofcom saying that the UK should adopt DABv2 but haven't updated my home page yet, but I can't think of any other important digital radio news.

And no, I'm definitely not looking for a scrap, although by the looks of it a lot of other posters on this forum are looking for a scrap with me.

Well obviously you're waiting for the tests to fail before you'll write about it, since you come across as quite obsessed about DAB.

Why not make some contributions to other topics on the board? You might learn a bit more about what RTÉ actually do then.

david23 wrote:

According to the respected UK audio coding expert Dr David Robinson (whose work is quoted extensively on your website) 192kbps MP2 is "rarely worse than FM, sometimes much better". He describes 160kbps MP2 as being "similar" to FM. Do you disagree with his view on this?

http://www.david.robinson.org/commsbill#1_2_3

I know David, thanks, and I know that his view on this has changed completely. He now has a far higher opinion of FM than he did.

FYI, when he wrote that article he only went off a few FM samples that were unfortunately provided by a couple of people with so-so FM reception, and IIRC mainly of classical music (so no pop or rock music masking the hiss...).

David now has a Denon TU260L Mk2 FM tuner (I've got the Denon TU260L Mk1, and they are excellent tuners even though they only cost about £100 -- I think David got his for about £30 on ebay), which is probably why his view on FM has changed so markedly.

MYOB wrote:

Virtually identical != the same

Erm, yes, but virtually identical does mean that they're very, very, very, very, very, very nearly the same, which means that there's very, very, very, very, very little work needs to be done to alter the code to support DABv2 if DMB code has already been written -- which it has.

In your little world, it sees the light of day. But have any broadcasters and any radio (NOT decoder module) manufacturers committed to it yet, anywhere in the world?

So, you have a go at me for being patronising and obnoxious, and you say

"In your little world"????????

No country has formally committed to DABv2 yet, but the Australian minister virtually did when she said this:

"Let’s face it, adoption now of a standard that is already 10 years old and may well be superseded, for implementation in another 2 to 3 years, would, in my view, be irresponsible.
Markets like the UK do not have the luxury of contemplating these more advanced standards, given they have an existing platform and would therefore face legacy issues.
But Australia does not have those legacy issues. We need to be absolutely confident we are not adopting a platform that could shortly be considered a legacy problem.
We are not alone in being at this point. There are a number of other large markets yet to introduce digital radio, including France, that will also need to determine whether to adopt a mature and now inefficient standard, or take advantage of technological advances."

Face it, you're backing a system that is on its way out. End of story.

Reading Digitalradiotec's posts I'm reminded of the horror of the UK TV industry when Sky announced they would broadcast in 625 line PAL from Astra 1 rather than the spiffy D-MAC system that the BBC, IBA and BREMA were sponsoring.

And who won out? The definitely superior D-MAC or the widely available PAL?

Likewise most would agree Betamax was a superior system to VHS, yet VHS won out in the end, simply because more manufacturers were geared up to provide kit.

We can argue the toss as to the superiority of DAB V2 over DAB V1, but at the end of the day, there's a lot of DAB V1 receivers available at a lowish cost and RTÉ want to reach that audience.

Maybe there's a better alternative, but right now those recievers are not available and for me personally, DAB is way superior to FM.

Why? Because here in North London we are plagued by pirate stations that camp near the frequencies of licenced stations and the result is bad interference that renders the FM versions of those stations unlistenable.

I happen to live in a reception black spot for UHF TV and FM radio. So I can only pick up the BBC FMs and Classic FM clearly on FM in my kitchen. With my DAB radios (yes, I have a few around the house ) I can get all the local London FM stations clearly and of course the extra DAB stations as well.

I can listen to Virgin, Capital FM and Smooth FM in DAB in my car and I don't get pirate stations ruining the reception across the city. DAB reception for me is far more stable than FM and I won't be ditching DAB any time soon.

Of course I can get RTÉ Radio 1 on LW as well but if a cheaper, portable DRM receiver with DAB V1 and if possible DAB V2 comes along, I'll buy that.

I've encouraged my friends to buy DAB radios and without exception, they all love it, as DAB gives a wider choice and interference-free reception.

MYOB wrote:

I'm not "backing" DAB, I'm saying its completely pointless to stand still and wait, for all eternity, for 'something better' to come along.

Look at any field of broadcasting or technology and you'll see that if you stand still waiting, you'll be waiting forever. You can wait and wait and wait for whats coming next, and you'll never get there as there will always be a new development or a replacing technology

RTE have the equipment, and they have transmissions. There is no point in them waiting for an unspecified length of time to jump onto a system that absolutely nobody is using yet.

You are definitely backing DABv1 -- if you weren't this evening must have been a long hallucination.

And as for waiting for all eternity for something better to come along, clearly you don't take much notice of what I write, because as I've said many, many times, DABv2 standards will be out in the next few months (I've seen this in an article written by a senior member of the worldwide DAB industry), and as I've also said many, many times, receivers can be ready very, very soon afterwards.

My point about waiting is that if you rush in now you're stuck with DABv1 for probably 10 years until you can switch over to DABv2 like everybody else. Or, you can wait a few months (literally) you can start with DABv2 and you won't have to endure 10 years of low audio quality.

You like to post history lessons about broadcasting, so here's one of my own: look at how long FM and AM have been going, and then think about how long DAB will be around if you adopt it. That's why I'm so adamant that you've got to choose the right system FROM THE START.

rlogue wrote:

Maybe there's a better alternative, but right now those recievers are not available and for me personally, DAB is way superior to FM.

Why? Because here in North London we are plagued by pirate stations that camp near the frequencies of licenced stations and the result is bad interference that renders the FM versions of those stations unlistenable.

I happen to live in a reception black spot for UHF TV and FM radio.

Sorry, but DAB provides massively inferior audio quality to FM. You may get poor FM reception and pirates, but you are unlucky. Sorry, but that is the truth whether you're willing to accept it or not.

128kbps MP2? Do me a favour - it's unlistenable rubbish on a hi-fi system. I don't care about audio quality on small portable radios, but I'm not listening to that muck on my hi-fi system.