DAB multiplex pages now have coverage maps
Brian Butterworth published on UK Free TV The pages that show the list of transmitters with a given DAB multiplex on them now show the primary reception area for the multiplex.
For example, here is the "London 3" coverage map:
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Thursday, 21 July 2011
As you've used London 3 as an example, it is interesting to compare it with the coverage map DRg publish for London 3: The Digital Radio Group (London) Ltd - London's third DAB
multiplex
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Friday, 22 July 2011
Ash: To be fair, the page you have linked to is coverage for the higher powered London 1 and London 2 multiplexes.
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Trevor Harris11:55 AM
Very interesting.
I did a quick check and found that from the Guildford transmitter the the signal strenth was greater for London 3 than London 1 when the opposite should be true.
I live in the Guildford area and looking at these maps shows how poor the coverage still is. You cannot go into a shop and buy a DAB radio and know that it will work.
It has been estimated that it will take a total of 1000 transmitters to provide the 99% coverage. When I look at these maps I wonder if that is not an underestimate. Dorset has very little coverage. Up to now the BBC has been able to cosite transmitters with existing FM transmitters. To fill in all the white space they are going to have to buy new sites which is going to increase the costs even further. On a previous post I estimated the cost of going to 99% but I had based this on previous costings. Clearly this would be an under estimate. In the end the DAB national multiplexes are going to cost many times the cost of the existing FM network.
As the BBC has admitted it is not yet known if it is technically possible to reach Ofcoms 99% target. I do feel that the BBC should have done this study before embarking on this white elephant.
Looking at this map shows how poor the comercial DAB coverage is. As I have said before no DAB only radio station is makeing a profit and will eventually disappear.
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Mike Dimmick12:23 PM
Briantist: No, it is not for the London 1 and London 2 multiplexes, unless Arqiva have supplied the wrong map. The website Ash linked to is specifically for the London 3 multiplex, which is licensed to a different operator from the other two (each is a different operator).
The linked map does appear to be the correct map, because it shows the Brookmans Park transmitter near Potters Bar. Neither London 1 nor London 2 use this transmitter.
I think you need to go back and figure out why your maps don't correspond to Arqiva's published coverage maps.
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Andy Fraser
12:33 PM
12:33 PM
The link for "DAB transmitters, multiplexes and radio stations" doesn't seem to work at the moment.
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Mike Dimmick: Sorry, I misunderstood the text at the bottom of the page.
The map, http://www.thedigitalradiogroup.co.uk/map.jpg has cyan for 58dbuV/m to 61dbuV/m, and the purple for for 61dbuV/m and above.
One possible reason for the supplied map being different is it doesn't really seem to take into account the angular restrictions provided in the Ofcom document, but I can't see Arqiva making that error for a commercial coverage map.
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Trevor Harris: As I understand it from the BBC briefing that I had, they will be able to use existing mobile phone masts, of which there are a considerable number, when they need to get down to covering smaller in-fill areas.
Such sites already have the necessary data connections, so this keeps costs down to a reasonable level.
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Trevor Harris2:20 PM
@Brianist
The use of mobile masts is interesting but I would have thought they are not tall enough as cells are actually quite small. The Guildford masts are quite alot taller than most mobile masts.
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Mark6:14 PM
The BBC will not need anywhere need 1,000 masts for DAB.
The FM figures quoted by Ofcom for BBC national radio are: 94.9% for robust indoor coverage, 99.1% for variable coverage.
The BBC has a plan in place for 97.2% robust indoor DAB coverage, so clearly some people with poor FM are going to benefit with a strong DAB signal.
The number of transmitters required for this is 404. Even with the law of diminishing returns it's clear that the BBC will not be building 1,000 transmitters (which would be 596 just to serve 1.9% of the population.
The BBC will be doing more planning work this summer around their existing network to lift the figure above 97.2%. The document submitted to Ofcom on 14th June 2011 is subject to amendments because of this.
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