Thankyou for the antenna calculation; smaller than I had assumed – no doubt future boy racers will opt for two fins joined together with a wing!

Just a small point about multiple antennas on a car.
You said “No doubt a technical solution (other than multiple antenna arrays on a car)”

Personally although I’m against using multiple antennas at lower frequencies I think it is perfectly acceptable at 3G frequencies, where the wavelength is much smaller. If I understand correctly 3G uses frequencies a bit higher than 2Ghz. A few calculations give the wavelength at 2Ghz to be about 15cm, so a 1/4 wave antenna would have a length of just 3.75 cm, and spacing between antennas, in a multi antenna system would also be something similar to this.

So rather than having to fit multiple antennas to a car, you could be fitting just one small plastic box that would already have the multiple antennas built into it.

I’m sure somebody could design an elegant looking small plastic box to go on a car, perhaps a small aerodynamic looking fin or something. I don’t see that being a being problem.

@Peter Wilkinson
I’m assuming, that the reason for mobile operators currently backing away from unlimited mobile broadband, is the cost of providing data capacity. Basically they can’t afford to do it at the moment. However the different mobile operators are competing with each other for customers, and most people would prefer an unlimited connection. So if better technologies make it more affordable to provide it, then perhaps we will eventually see unlimited services being offered. Or perhaps broadband with a higher download limit, that does allow people to listen to a reasonable amount of internet radio. Who knows, we will have to wait and see what happens.

Indeed there may well be merit in your vision of the future of 3G system networks but are you also hinting at a Pay as you Listen scenario?

Nevertheless relieved to know that one does not necessarily need a degree in broadcast engineering to appreciate what ones ears tell you! From the moment I first heard DAB on a high end Arcam unit at the Bristol HiFi show a few years back, I thought that it was a backward leap in sound quality compared to FM.

An inappropriate observation I hear James muttering, but perhaps one needs to be outside of the wood to see the trees. Obviously one would not make the same comparison to AM (Amplitude Modulated as distinct from Frequency Modulated).

DAB does have some technical merit, despite its MPEG2 origins,such as transmitter overlap/combining without phase anomalies. However the extent of data reduction (MUSICAM system) employed by broadcasters is way in excess of that recommended by the BBC`s own R & D engineers back in 1994 when they stated the minimum bit rate for digital STEREO broadcasting to be 190kbps; below which all sorts of audible nasties would manifest themselves. Current transmissions ranging from 80 to 120kbps thus being a contributory factor to the ABYSMAL quality compared to FM that some of us can hear. I hasten to add I do not expect Bernie Grundman or Mobile Fidelity Sound Labs mastering quality, just something better than FM for the exercise to be worthwhile.

Thus I am not adverse to progress but when DAB, as currently implemented, is falsely promoted (just listen to the adverts over the last few years) by the industry as an improvement over FM in order to boost sales, I sense commercial exploitation and manipulation. I wonder how many of those dedicated DAB radios sold have been returned for a refund (as per my son`s)and how many of those combined DAB/FM radios sold are merely used in FM mode out of desperation! Neither statistic will ever be recorded let alone officially voiced and we will eventually have DAB by default at a theoretical sale threshold of 51% digital radio units in use (2015 or later).

Nevertheless some comfort can be taken from the Minister`s (Mr.Vaizey`s) statement yesterday that all future DAB chipsets are to incorporate a DAB+ module, although no DAB+ broadcast commitment is being made at this stage. Possibly a case of paying lip service to current criticisms but only time will tell.

Whatever the future outcome, 3G and other internet based technologies included, FM will indeed continue, as James has rightly said, BUT only for local radio stations – there will not be any National service.

“The thing that did strike me about all this is that you seem to have based everything on the 3G networks as they are today. Now I’m not saying that mobile broadband will definitely change in a way that makes it ideal for internet radio, but I wouldn’t rule it out either.”
…absolutely, I think we’re agreed. However, given that the 3G networks aren’t even ubiquitous today (3G isn’t even consistently available on the M25!) would tend to indicate that this is many years in the future, and it’s a tremendous risk to bet the future of the entire radio industry on the mobile networks implementing “new protocols which would probably need to be invented”. That’s why I haven’t done it.

In terms of audio quality: it would appear you believe ‘abysmal’ to mean something different than I do, or the majority of the listening public (who increase their radio listening after purchasing a DAB radio). I can hear the digital-ness of a DAB signal, and it does sound ‘different’ to FM; but ‘abysmal’ it isn’t. However, I’m pleased that, unlike others who frequent alt.radio.digital with you, you’re not trying to claim that DAB sounds worse than AM.

I’ve just read your comment about DAB sound quality:

“The audio quality of DAB is perfectly acceptable to most, and for most stations is considerably better than anything but a perfect FM signal. Using the word ‘abysmal’ next to DAB’s audio quality betrays a lack of understanding about the subject matter.”

Well perhaps you are not listening to the same DAB that used to drive me mad. I think Abysmal is an appropriate description for DAB sound quality, and just to prove that I do understand the subject matter:

DAB is based upon the mp2 codec, which needs about 256k to provide good sound quality for music. But with DAB they mostly use about 1/2 that.

So to make DAB work at only 128k they have to use intensity stereo, which is basically mono with a parameter for each sub band to decide the position of the sound between left and right. This creates a horrible flat quality to the stereo image, because all the phase information is lost.

The intensity stereo only works on the higher frequencies, but is still very noticeable. I tried listening to DAB for about 18 months, and found it increasingly trying to listen to. Then when I gave up and switched back to FM it sounded so soothing and easy to listen to compared to DAB.

In the end I didn’t need technical knowledge to notice what my own ears tell me, that DAB sounds horrible. But as it happens I do understand the reasons why DAB sounds horrible.

The thing that did strike me about all this is that you seem to have based everything on the 3G networks as they are today.

Now I’m not saying that mobile broadband will definitely change in a way that makes it ideal for internet radio, but I wouldn’t rule it out either.

Now I’d better confess at this point, that I don’t know all the details about all the new technologies. However I can see 2 main ways in which things could improve.

Firstly more advanced transmission systems, substantially increasing the data capacity in a given channel. That on it’s own probably wouldn’t be enough if everything was unicast.

But then why couldn’t they devise a system that broadcasts the most heavily used web streams, so that many users in the area could receive the same stream using the same bandwidth. Obviously existing protocols such as IP are not designed to work this way, so some new protocols would probably need to be invented. So why not invent them. For example, a mobile device could send a request via IP to say that it wants to connect to a stream, and then the mobile network could send a reply to tell the mobile how to connect to it. Either by connecting to a broadcasts channel, or by a unicast channel, which ever was the more appropriate for that particular stream.

There is of course the question of who will pay for such a system, and why. Well the new technologies would benefit the mobile phone companies. Why stay using the old 3G system when newer technologies will allow them to connect more customers, and hence make more money. Both increasing capacity, and using broadcast channels, would drive down the cost per customer. Allowing them to offer more services to more people, and hence make more money.

Also as technology makes it cheaper to provide services, mobile phone companies would want to start offering better value packages, to compete with the other mobile phone companies.

Now I realise that this is all probably many years into the future, and a lot of things could happen in that time. So none of this is certain. But I think it is a mistake to rule it all out, just because the 3G networks of today aren’t up to the task.

What more can one ask?

There’s no “followers” on here.

The ConLib administration isn’t getting rid of FM. It’ll still be part of the radio landscape.

The audio quality of DAB is perfectly acceptable to most, and for most stations is considerably better than anything but a perfect FM signal. Using the word ‘abysmal’ next to DAB’s audio quality betrays a lack of understanding about the subject matter.

Mr.Vaizey`s email address is vaizeye@parliament.uk

Suggest sending him some enlightenment as to the necessity to maintain FM as part of a multi-platform; especially while both coverage and quality (very low bit rates)remain so abysmal.

http://www.bbc.co.uk/radio/help/faq/dab_bitrates.shtml

However, it isn’t really fair comparing with online bitrates, as the codec used online are more efficient.

That’s why, of course, DAB+ would be useful, as the same bitrate gives better quality.

So, bitrates could be increased on DAB, but you would just get four 320kb/s on each multiplex.

James, when he was at the BBC, fixed it so that the iPlayer bitrates are the best, and there are also very good quality WindowsMedia streams.

http://iplayerhelp.external.bbc.co.uk/help/streaming_programmes/real_wma_streams

If the BBC dump the Asian Network from DAB, then there will be more for Radios 1 and 2.

“As part of the deal, up to 160 new DAB transmitters will provide better coverage for BBC digital radio over the contract period, which last until 2023. ”

http://www.ukfree.tv/fullstory.php?storyid=1107051161

No new money has been allocated to change this, whatever the Digital Economy Act says.

There is no switch-off planned.

Here’s what happens.

First, total digital radio listening has to get to over 50%. It’s less than 25% right now, and the BBC are performing considerably worse than commercial radio.

Second, the target date for this is 2013. I can’t see that happening.

Third, once the 50% has been hit, it’s then the government can decide to switch off some FM radio stations (like national FM radio and some of the big locals). The target date for this to happen is 2015.

If 50% has been reached in 2013, that means that FM switchoff could happen in 2015. Which, I might remind you, is the date of the next election, which has already been announced.

1. It would be a brave government to be responsible for forcing 45% of the population to buy a new set of radios for their minority-used sets in the house.
2. It would be a really brave industry to switch off a platform which still serves around 45% of its listeners.

Now, given that, I’d humbly submit to you that there is no chance of FM switchoff as one big hit.

My view, for what it’s worth, is that individual stations should be free to switch off analogue as soon as possible. Absolute reckon they might not bother reapplying for their AM licence. I wouldn’t blame them, since they’ve already hit the 50% figure, and their AM transmitters cost a huge amount. But: a big FM switchoff? Nah.

Now, continue stirring up false worries for people, but really, I can’t see anything to be worried about in the future. The future of radio is a multiplatform future.