Many thanks to SWLing Post contributor, Jason Whiteley, who writes:
[T]here is a really interesting interview with Radio France here around their DAB+ expansion and the possible shut down of FM in France later [click here to read].
I used Google Translate to bring it to English.
[Y]ou might also choose to link to this article about AM radio being dead in Europe (written in 2015):
The article is bang on though – AM radio is still very strong and thriving in Australia & the USA. Here in Australia at least, it’s DAB that has a minimal audience compared to traditional AM broadcast.
I just found both of these articles very interesting reading and thought you might like to put them up.
Have a great day,
Thank you very much for sharing these articles, Jason! Earlier today, we posted a note about digital AM here in the States (AM HD). There is a movement to increase this offering, but for true market penetration it would require car radios that can receive AM HD. Many a DXer dislikes AM HD because the digital signals are (unlike DAB+) inserted between analog signals. These band crowding sometimes causes interference to adjacent analog stations and certainly affects mediumwave DXing.
HD in the AM band in the USA is bad because for all but one station the digital signals occupy the adjacent channels used by other broadcasters. Also the power of the digital signal is so low that the reliable coverage of the digital signal is much reduced particularly because of the high level of impulse interference from power line insulators, the widespread use of switch mode power supplies and vehicles. In addition around 67 % of the radiated power contains no audio or data.
The USA has never had a side by side comparison with DRM which has replaced the power guzzling carrier with some low power pilot signals. The bandwidth of the DRM signal is selectable from 4.5 – 20 kHz.
Much of the above post about Australia is opinion and not facts
The current number of listeners is greater than portrayed in the above post http://www.digitalradioplus.com.au/latest-news/2019-(1)/big-audience-boost-for-dab-radio-stations
The coverage area for the DAB+ signals is all capital cities only. This covers around 14 million people. on the digital radio plus website there are ratings figures in population values including DAB+ only programming.
The criticism of the 48 kbit/s bit radio was pushed for a long time on another forum. When challenged to name the program and to describe the effect caused by the low data rate the poster could not do it. He has now gone quiet on the topic. Jason needs to do a double blind test between an original CD and the broadcast version of the same audio where he doesn’t know the source. All metropolitan AM stations are simulcast and the addition of stereo and the high pitched sounds makes the sound very good.
Australia has chosen to continue to use band 3 (VHF high) for television leaving a minimum of 2 TV channels spare. These provide 8 DAB+ transmission channels. Currently 3 DAB+ channels are used in biggest cities and 2 in the smaller ones.
The coverage area for FM and DAB+ are strongly controlled by the height of the transmitting and receiving antennas, and the transmitted power. In both cases hills, buildings particularly those with metal roofs and concrete reinforcement absorb these signals. In Sydney the major FM broadcasters use 250 kW radiated power where as DAB+ is 50 kW. To overcome this there is DAB+ repeaters reradiating the signal on the same channel. FM in Australia has never had a reliable radius o 200 km, just like DAB+ will go further than 30 km. Have a look at an Adelaide suburb on http://reception.abc.net.au/ and select map for Triple J for FM and Triple J unearthed for DAB+. The AM distances really only apply at night when the ionosphere will reflect the signals back to earth. You can’t use the 50 kW AM stations of the ABC as the standard when the highest power of a commercial station is 5 kW.
The reason why SEN is no in Adelaide is because it is a Melbourne station and that is where it is licenced to broadcast. In addition Brisbane, Sydney and Melbourne have 2 commercial DAB+ transmitters each Adelaide, Perth, Hobart, Canberra and Darwin have one each.
There is an encoding/decoding delay to stop impulse interference which is obvious at the ground, however the ABC promotes the use of using the phone which has an even longer delay.
I should remind all, that in 2009, Australia was the first country in the world to start permanent DAB+ broadcasting at high power.
It is designed for areas of high population densities because of its capacity to carry many broadcasters on one transmitter. Our capital cities are the only areas with high population densities. The use of 200 MHz means that the coverage area is smaller than lower frequencies, which is why is a poor choice for the rest of Australia with its low population density. A much better choice is DRM which will operate from 526 kHz up to 108 MHz.
Southern Cross Austereo owns the most commercial stations in Australia covering many regional areas and 2 stations in each capital city (MMM and Hits) There are no independent commercial stations in capital cities. There is also additional regional commercial networks and a few independent stations.
In each DAB+ transmission area there is a single transmitter which only carries ABC/SBS signals. City wide community stations are carried on the commercial transmitter and is allocated 2 of the 9 data ensembles.
To expand digital radio, DRM (www.drm.org) will need to be used, with DRM+ for capital cities and major regional areas using the vacant analog TV channels 0 – 2, and DRM30 for remote areas because of its capacity to cover large areas. The ABC and SBS could cover the whole of Australia with one transmitter per program using high frequency DRM.
DRM now covers India at high power, and there is already over 1 million cars with DRM radios fitted prior to sale.
The Australian rollout is the way to do a digital radio rollout using the best technology for the application
DAB+ is best for capital cities, DRM+ for community broadcasts covering only parts of these cites and DRM+/DRM30 in the rest of the country.
What we need to do is to follow Norway and switchoff analog radio, where DAB+ is in use and start DRM broadcasting elsewhere. This includes DRM broadcasts from Radio Australia
DAB+ has several problems in Australia
1) the sound quality is max 48kbps AAC, for many staions you can find higher bitrates online.
2) the range (being VHF channel 9A) is limited to about 30kms from a tower
3) There is no regional DAB+ and there is no great push to have it either considering that FM and get out up to 200kms from a tower and AM much further than that (300-400kms at a low frequency with reasonable power)
4) There is a whole world of AM/FM stations in Australia that aren’t on DAB+ and probably never will be. Commercial broadcasters paid for those multiplexes and they decide which community stations can go on. In my own city of Adelaide there is a commercial broadcaster (SEN) who isn’t on DAB+
5) fans of live sport won’t use digital radios as there is too much delay especially if you are at the ground. You need analogue at the football or cricket.
The whole rollout of DAB+ in Australia was a cockup from go to whoa. Between the Government treating it as another revenue-raising mobile-like spectrum auction, major media companies & the commercial radio lobby group treating it as an opportunity to lock out potential competitors, and being caught up in the spectrum regulator’s ongoing channel re-allocation for digital TV, it was a complete mess.
That’s why we ended up with a situation of:
* capital city coverage only (outside of them, radio tends to be owned by independent local or regional networks)
* no/few new entrants (any new ones are either related to existing radio licencees, or leasing capacity from them)
* limited space for non-commercial/non-national community stations (the national broadcasters ABC & SBS are forced to allocate a little space to them, otherwise they have to lease space commercially)
* limited expansion capacity (trapped into the gaps of the VHF TV spectrum, half of which are unavailable in metro areas)
* talkback/sports running equal or better bitrates than music stations (generally, there’s talkback/sports networks & music networks – and both were allocated the same number of those mux slots in the initial offering)
* everybody being unwilling/unable to expand beyond the major capital cities for mainly commercial reasons (the major media companies/lobby group aren’t interested in paying to roll out DAB+ in regional towns, but expect the national broadcasters [ABC & SBS] do it & give them first option on available mux slots).
It’s like a DAB/DAB+ “HowNotTo” …