IET
Decrease font size
Increase font size
Topic Title: Energy consumption and reception of Digital Radio compared with Analogue FM
Topic Summary: Portable and Car Radio performance (Analog FM DAB and DRM+ compared)
Created On: 26 April 2013 09:54 PM
Status: Read Only
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 26 April 2013 09:54 PM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

I am looking for evidence on the energy performance and reception performance of the two main digital radio standards (DAB and DRM+) compared with Analog FM

Conclusion of a report written by Lindsay Cornell

"RESULTS OF THE DRM+ HIGH POWER FIELD
TRIAL IN THE UNITED KINGDOM"

http://public-service.net/docu/WHP199.pdf

"Conclusions
DRM+ was extensively tested in the UK in a highly credible 'real environment'. The frequency and antenna system was previously used by a commercial FM station. A large number of measurements were taken over an extended period and extensive geography with a calibrated receiving system and analysis was performed on the data.
The trial has shown that DRM+ is capable of excellent coverage in good quality at reduced power levels compared with FM and that as expected 4-QAM was more robust than 16-QAM. Urban coverage was superior to FM, especially in the more rugged 4-QAM mode, because despite a few
drop-outs, the overall subjective experience was found to be better than that of FM with noise, clicks and fuzz. The audio decoding method includes error concealment algorithms to fade-out to silence when audio frame errors are detected and fade-in again when the error rate falls. In rural areas, the coverage was also excellent although terrain shielding did cause some audio failure, although this was comparable to the experience with FM from the co-sited transmitters."

So DRM+ is better on balance in terms of mobile reception and energy efficiency than Analog FM. I know that DAB is considered worse than Analog FM in terms of mobile reception and energy efficiency.

Therefore I have started to ask the obvious question again.

Why are are we moving to the in car use of DAB when it is worse than either of the other two alternatives, doing nothing or gradually moving over to DRM+ in the FM band. I think there are 4 digital DRM+ channels added for each analogue FM channel lost, so a gradual rollout would not be two difficult.

I doing think there have been any comprehensive engineering trials comparing the three technologies side by side, in terms of energy requirements, reception performance etc.

Ofcom have denied all responsibility for the digital switch over pollicy which is interesting, so I have sent an email to the dept of Culture. Media and Sport and now await there reply.

James Arathoon



-------------------------
James Arathoon
 26 April 2013 10:10 PM
User is offline View Users Profile Print this message



ectophile

Posts: 546
Joined: 17 September 2001

I can't seriously imagine the BBC telling all its listeners "Throw away all the new digital radios you've just bought. We're switching off DAB and using DRM+ instead. So you're going to have to go out and buy a whole new set of digital radios".

It's not going to happen, even if DRM+ is better.

-------------------------
S P Barker BSc PhD MIET
 26 April 2013 11:54 PM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

How many people have a DAB radio in their car?

Apparently uptake of DAB is at 30% (indeed I have been given a DAB radio for free, but it useless and I never use it).

Once uptake reaches 50% (however that is calculated - useless freebees included I presume) the remaining 99% of people with analogue radios still fitted in their cars will suddenly find they have no service.

Who is being unreasonable here and who is being unreasonable?

How come you equate keeping Analogue FM, or gradually and intelligently moving to a mix of analogue FM and DRM+ radio channels in the FM band, as being a draconian move to suddenly ban DAB. I said nothing of the sort.

It is the DAB ethusiasts who want to deny competition and choice, and get rid of other options before they have been properly evaluated by consumer watchdogs and independent engineering experts.

Whether the Department of Culture, Media and Sport will allow a privately funded DRM+ consortium to openly compete with DigitalUK (owned by the cultural elite, the BBC, ITV, Channel 4 and Arqiva) for car radio listeners I don't know yet.

Ofcom certainly aren't interested in getting involved, which is slightly strange. However the BBC know all about DRM (the original version on the AM band) and because they are broadcasting using DRM digital radio across most of europe right now.

So the BBC license fee payer is funding DAB here and yet DRM elsewhere across europe.

James Arathoon

-------------------------
James Arathoon
 27 April 2013 08:57 AM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

Originally posted by: ectophile

I can't seriously imagine the BBC telling all its listeners "Throw away all the new digital radios you've just bought.".


That's exactly what the cultural elite will have us do anyway by abandoning DAB for the improved DAB+ standard, which the older and the cheaper players won't be able to convert to.

This is what "which?" are saying at the moment

http://www.which.co.uk/technol...guides/dab-explained/

"What will happen if DAB+ replaces DAB?"

"If DAB was dropped in favour of DAB+, radios that can't be upgraded to receive the DAB+ signal would become obsolete. However, many newer DAB radios contain a multi-standard chip, so they are DAB+ compatible. Other models with a USB port or wi-fi connectivity may be upgradable in the future.

If DAB+ was adopted in the UK, it's likely that there'd be a period when the two digital systems would run alongside one another. This would allow some stations to be broadcast in the new format and some in the old, giving listeners time to switch to the new standard. We look for DAB+ compatibility in our digital radio tests."

So we are going to end up with two switch-offs that make hardware obsolete. The FM switch-off still officially set at 2015 and the evental switchover from DAB to DAB+.

Which? again....

"Is it worth buying a new digital radio?"

"Don't be put off buying a DAB radio

If you're planning to buy a new digital radio, don't let the news about DAB+ put you off. UK government [DigitalUK a public/private consortium to be correct] seems committed to a DAB, rather than DAB+ future and as a national digital radio switchover from FM to DAB is unlikely before 2015 at the earliest, any potential change to DAB+ looks to be even further off.

A multi-standard chip that's DAB and DAB+ compatible was introduced in 2009. Models fitted with this chip are future proofed for compatibility with DAB+ as well as being compatible with DAB. So DAB+ compatible models, or those that can be upgraded, are already available from many big players in the UK digital radio market, including Pure and Roberts."

So we currently have to buy bloated and energy inefficient hardware capable of meeting the specification for DAB and DAB+ to guarantee that our investment will not be obsolete a few years down the line. The broadcasters will have to modulate and transmit DAB and DAB+ signals in the switchover period which will eventually be needed.

Now the FM switch-off is still officially hanging over us and could currently come at anytime at all post 2015 (presumably after the next general election - as the policy it's not going to be a vote winner). In the meantime the Department of Culture Media and Sport and Ofcom are trying to say as little about it as they can get away with.

I think the cutural elite in this country have to decide exactly what they want to do before the next general election, otherwise a potentially new set of politicians will get bamboozeled by the civil service into the inevitibility of suddenly decommissioning 25 million analog car radios (on the FM band) with little or no warning.

I say take away DigitalUK's cultural monopoly on this and let car driving consumers decide, what they want in their cars the choices are DAB/DAB+ or DRM/DRM+ or continuing with Analog AM/FM.

James Arathoon

-------------------------
James Arathoon
 27 April 2013 11:26 AM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

Lets say the BBC take its national Radio 3 off FM and leave it on DAB etc.

(Apparently the perceived sound fidelity obtainable with DAB and DRM+ broadcasts compared with analogue FM is in large part subjective. I am not choosing Radio 3 for sound fidelity reasons, but because it is the least listened to BBC radio service on FM)

Now the BBC can add back Radio 1, 2 3 and 4 to a National DRM+ service for in car use with minimal disruption.

Commercial radio can do the same, lose the least listened to service on FM and then add it back as a DRM+ broadcast along with 3 other more popular commercial stations that also stay on FM for the time being.

Maybe there are some other things that can be done, such as sending digital data over radio to get digital radios to handover to commercial partner stations when you drive into a new region or put out separate travel information, something that home listeners aren't necessarily interested in.

It is well known that with DAB the problem with radio dead zones in our towns and cities will increase. The solution to this apparently is increasing the power of the transmissions and in some cases adding more transmitters.

How much energy is required for DAB broadcasts compared with DRM+ to get the same uk coverage and sevice levels? This is a legitimate question for an engineer to ask.

What if people start complaining about DAB car reception problems in our increasingly built up towns and cities? Potential problems that broadcast engineers have been aware of all along, but were too afraid to talk about publicly, for fear of offending the sensibilites of the cultural elite?

James Arathoon

-------------------------
James Arathoon
 27 April 2013 12:01 PM
User is offline View Users Profile Print this message



dsergeant

Posts: 4
Joined: 14 September 2001

There is some confusion here. DAB and DAB+ are two versions of Digital Audio Broadcasting. DAB is our current UK system, DAB+ is used by the rest of Europe.

DRM+ is the Digital Radio Mondiale system, originally developed for short wave broadcasting and some use there. A totally different thing from DAB.

What the report says (although I have not yet read it) is that DRM/DRM+ offers superior performance to DAB (and presumably DAB+) and by inference DAB in all its forms was the wrong way to go. And it seems only concerned with the power transmission of transmitters, not that of receivers which tend to be rather more power thirsty than their FM equivalents.

Also one of those who has a FM/DAB radio that spends all its time on FM...

-------------------------
dsergeant
 27 April 2013 01:24 PM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

dsergeant,

The above report only compared analogue FM with DRM+ (transmitted on the FM band).

But I agree clarity is not helped by using the DAB and DAB+ acronyms which represent incompatible technologies. Also DRM and DRM+ are confusing as well. DRM is a AM band digital modulation system and DRM+ is the technically equivalent FM band digital modulation system.

Large countries like india can cost effectively use DRM for national broadcast coverage, much smaller countries like the UK can choose to use DRM+ for national coverage (in energy, transmitter count and supporting infrastructure terms DRM+ will not be cost effective for national coverage in countries like India) .

All three (Analogue FM, DRM+ (Digitally modulated in the FM band, but using the same transmitter as Analogue FM) and DAB) should be properly compared for in car use (by experienced engineers) before we unilateraly decide to decommission 27.5 million car radios, 3.4 million truck and van radios, up to 178,000 bus and coach radios all in one go (2005 estimates from Wolfram Alpha)

I estimate that on average a new vehicle radio it will cost at least £200 to remove the old radio, and then supply and install the new radio. That is a cost of up £6.2 billion on new car radios. No doubt shortages in the supply chain will cause prices to shoot up, meaning the less wealthy are left listening to crackly AM analogue services, whilst the supply chain restocks with cheaper radios.

Taking BBC radio 3 off the air as a national Analogue FM broadcast seems to me like a very sensible strategy.

http://www.bbc.co.uk/blogs/rad...ut-awards-and-a.shtml

"The Radio 3 audience has dipped a little this last quarter, a quarter which saw a non-stop Schubert celebration for eight days in March - but this is not a reason. Radio 3 audience figures do fluctuate around the 2m mark, and we had a strong end to last year, but the amount of time that our listeners listen to us is up year on year - - audience figures are only one measure of our success. "

Audience figures for BBC radio 3
http://www.mediauk.com/radio/3...o-3/listening-figures

They don't break down the figures between in-car listening and residential listening.

http://www.mediauk.com/article...io-stations-in-the-uk

BBC radio 3 at around 2 million listeners is nowhere near the top ten

1. BBC Radio 2 (15.1m listeners every week)
2. BBC Radio 1 (11.1m)
3. BBC Radio 4* (10.8m)
4. Heart (7.4m)
5. Capital (6.8m)
6. BBC Radio 5 live* (6.3m)
7. Classic FM (5.4m)
8. Kiss (4.3m)
9. Smooth Radio* (3.8m)
10. Magic (3.8m)

(Source http://www.mediauk.com/article...dio-stations-in-the-uk )

There are benefits to using digital radio in cars: for example digital travel information can be filtered appropriately for each particular driver if the car has a GPS or Galileo GPS receiver and the geographical position and speed of the car are known.

James Arathoon

-------------------------
James Arathoon
 28 April 2013 10:43 PM
User is offline View Users Profile Print this message



ectophile

Posts: 546
Joined: 17 September 2001

Personally, I would be happier if the BBC gave up advertising digital radio entirely. To me, it's a solution without a problem. I don't really care if it's DAB, DAB+, DRM or DRM+.

FM radio works. It's simple and cheap to make a receiver, and an FM radio can run for ages on battery power alone. We already have RDS to add a limited data capacity for channel identification.

Digital radios are more complicated, more expensive and power hungry.

New technologies don't catch on just because they are technically better. People must see a need for them, and want to go out and buy the equipment. We already have AM, FM and DAB. I can't see the radio companies wanting to run another, completely incompatible, digital radio system in parallel with DAB. And I can't see the customers wanting to have to choose between two incompatible types of digital radio, knowing that one of them will inevitably be scrapped eventually when the other gets the bigger market share.

-------------------------
S P Barker BSc PhD MIET
 29 April 2013 12:12 AM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

I should have added a link to the governments Digital Radio Action Plan

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/77619/Digital_Radio_Action_Plan_Version_7.pdf

also a link to Ofcom's third annual Digital Radio Report.

http://stakeholders.ofcom.org....drr-2012/2012_DRR.pdf

This report puts the commercial national coverage for roads at 82.9% for the BBC (national), 63.5% for digital one (national) and 43.2% for aggregate of local multiplexes.

I wonder what the increase in energy consumption will need to be for DAB to raise these above the 90% coverage (that Analogue FM typically achieves). The costs of broadcasting on DAB are already much higher than for Analogue FM and this will only increase I presume.

There are some interesting critical thoughts on transmission costs in Steve Green's submission to parliament.

http://www.parliament.uk/docum...upload/stevegreen.pdf


As we saw in the report linked to in my first post, broadcasting using the DRM+ standard will if anything reduce transmitter power consumption compared with analogue fm broadcasts, whilst at the same time maintaining coverage.

The society of motor manufacturers seem very optimistic that all new cars will have a digital radio soon.

However from the current trends it doesn't seem that likely that ALL cars will be fitted with a digital radio receiver (as standard) by the end of this year (2013), which is what the motor industry has set as their target (see below).

http://www.smmt.co.uk/2013/01/...uptake-rises-in-2012/

If you extrapolate the steady increase in uptake percentage, then by the end of 2014 100% of new cars should be sold with a digital radio. But by this time receivers with the ability to receive DRM and DRM+ broadcasts may be available, so who knows what will happen to DAB as an in car UK digital standard then.

At the moment 66% of new cars are still sold without a digital radio and engineers hate to waste energy for no good reason.

James Arathoon

-------------------------
James Arathoon
 29 April 2013 10:17 AM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

Given that the software digital radio receivers are so similar in design it should be very easy to design DAB receivers that are future compatible with DRM+ as well as DAB+.

In particular DRM+ and DAB+ seem to use the same basic audio codec (HE AAC v2) which makes things even easier.

On the radio antenna side software RF receivers all appear to have the same basic architecture now,

(e.g. http://www.silabs.com/products...ers/Pages/si468x.aspx
)

and since all the DAB radios being produced at the moment are still designed to receive analog FM the RF antenna compatibility (for DRM+) is there by necessity.

I have discussed this in detail with one RF engineer ready and willing to help sort this mess out. From a systems integration point of view I've seen much much harder technical problems to sort out than this one, and and the RF engineers (I've met anyway) are easily up to the task.

(As usual there is no money available in the UK for doing sensible and energy efficient things. I estimate entrepreneurial funding in the region of £500,000 to £1,000,000 will be needed perhaps partly from the car manufacturers; the banks being a complete waste of space at the moment. The car manufacturers have everything to gain by future proofing their in car digital systems (from a brand image and a european product standardization point of view) ).

So it is not engineers holding back innovations of this sort, but probably the existance of the monopolistic and anti-competitive UK Digital Radio Troika system publicly bankrolled by BBC license fee payers which effectlive bars all commercial new entrants from entering the game (DigitalUK, Ofcom and Department of Culture Media and Sport)

James Arathoon

-------------------------
James Arathoon
 29 April 2013 11:11 AM
User is offline View Users Profile Print this message



amillar

Posts: 1918
Joined: 28 May 2002

Originally posted by: ectophile
FM radio works. It's simple and cheap to make a receiver, and an FM radio can run for ages on battery power alone. We already have RDS to add a limited data capacity for channel identification.

Digital radios are more complicated, more expensive and power hungry.


Couldn't agree more. We have four DAB radios (of four different makes). One mains powered unit is DAB only, it is a real pain because of the time it takes to turn on. Another battery powered DAB only radio we have given up with altogether because of the pathetic battery life. The other two work very well - on FM. In practice if we want to listen to non-FM radio we use a laptop.

The daft thing is that there is not even a projected use for the freed up airspace, so that part of (say) the digital TV argument does not apply.

It would be interesting to know if there is a reduction in transmitter power consumption for DAB and, if so, whether this will ever make up for the increase in receiver power consumption.

I remember the initial argument for DAB was that it would eliminate multi-path distortion with FM in cars. Has anyone ever actually found this to be a problem?

-------------------------
Andy Millar CEng MIET CMgr MCMI

http://www.linkedin.com/in/millarandy

"The aim of argument, or of discussion, should not be victory, but progress." Joseph Joubert
 29 April 2013 11:27 AM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

In terms of no new Bank lending, to help SME companies wanting to develop new energy efficient technologies...like the RF radio stuff described above...

This type of lending is non-existant at the moment because the banks are concentrating on another round of ripping-off the tax payer.

They are using the funding for lending schemes (dishonestly in my opinion) to roll over existing bad debt to effectively de-risk themselves using tax payer guarantees. This is born out by the lending figures - there is no new net lending going to the SME business commmunity.

Some of these debt roll-over will inevitably be targeted towards sub-prime loans (just by the laws of chance if nothing else); in this case this is money loaned out to zombie companies which in a few months time might end up going bust more at tax payer expense rather than bank shareholder expense.

James Arathoon

-------------------------
James Arathoon
 01 May 2013 12:53 PM
User is offline View Users Profile Print this message



jarathoon

Posts: 1041
Joined: 05 September 2004

Have written the following to Ofcom after they told me that digital radio switchover policy was the responsibility of the Department of Culture Media and Sport

Email below....




You are obviously not aware of this, but someone in Ofcom is required to chair the meetings of the "Joint Planning for Radio Group".

Can you advise where on your website you publish the meeting minutes for the "Joint Planning for Radio Group"?

Are you aware that Ofcom has to present a switchover plan to the JPRG by 10 July 2013?

See "Memorandum of understanding on Local DAB funding for Radio Switchover" published on 11 July 2012 for more details

https://www.gov.uk/government/publications/memorandum-of-understanding-on-local-dab-funding-for-radio-switchover

"2.1.6. The Parties shall each use best endeavours to ensure that the JPRG makes timely recommendations to Ofcom so as to ensure that Ofcom is able to present to DCMS, within 12 months of this MoU being signed:
2.1.6.1. a provisional Technical Switchover Plan; and
2.1.6.2. a provisional Switchover Implementation Plan,

Amongst other things these plans will identify locations where Government should give consideration to the appropriateness of full local DAB build-out to FM equivalence, consistent with delivering value for money."

Obviously someone in Ofcom is supposed to take the current official policy of the Department for Culture, Media & Sport seriously (even if I and other people don't) and attempt to come up with a switchover plan. So hopefully you will let me know who it is and forward my email to them, so I can find out when the next meeting of the JPRG is and perhaps arrange to attend as an observer.



-------------------------
James Arathoon
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.