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John Marsh
20th Mar 2018, 15:45
BBC scraps plans to turn off FM radio:

The BBC has cancelled plans to switch off FM radio broadcasts and force millions of listeners to tune into digital transmissions.

The corporation is set to announce FM will remain as part of a 'hybrid' future that will operate alongside DAB and the internet.

Bob Shennan, the director of BBC radio and music, will confirm the scrapping tomorrow, The Daily Telegraph reports.

He will also urge broadcasters to work together to ensure the survival of radio, saying Government plants to switch of analogue broadcast could restrict listeners' choice.

'We all once thought that DAB was the only digital future of radio, but audiences want choice,' Mr Shennan will tell a radio industry conference in Vienna.

'We now know DAB is important, but only part of the story, along with FM and the internet. We need to do more before we consider a switchover in the UK, and for that to be genuinely audience-led.'

Analogue radio was originally set to begin turning off in 2015 under Government plans.

But a weak take-up of DAB meant the plans were scrapped and ministers said a switchover would begin after digital audiences accounted for half of overall listening.

That threshold has already passed - with DAB accounting for 36 per cent and the internet leading digital audience with more than 50 per cent.

Last year commercial stations gained a higher shared of the population than the BBC for the first time.

Mr Shennan will add that broadcasters should keep transmitting analogue signals to protect traditional strongholds of radio listening, such as in cars.

Newer cars offer online streaming to apps including Spotify and Apple Music and are also connected to mobile internet.

The proliferation of faster 5G intenet 'has the potential to transform radio again', Mr Shennan will add.

Mr Shennan's appeal for commercial rivals in the radio industry to work together indicates an increasing fear at the BBC over the ever-widening choice for audiences online.

It comes after BBC deputy director general Anne Bulford asked the commercial television industry for greater collaboration to tackle the threat from Netlfix and Amazon.Daily Mail (http://www.dailymail.co.uk/news/article-5514415/BBC-scraps-plans-turn-FM-radio.html)

Mr Shennan recognises that "audiences want choice". I thought this was part of the attraction of DAB.

True, I can find extra programme content on DAB compared to FM. I can also experience limited-fidelity music stations, some in mono! Perhaps I should feed those through a 1950s FM wireless, for the full effect...

In fact, I prefer the sound of the FM outlets of the BBC national networks over their DAB counterparts. Despite those DAB bit rates being relatively generous.

I imagine this decision will benefit listeners in patchy DAB areas. 'Bubbling mud', anyone?

It's also good for the environment. There must be many millions of FM sets nationwide. Why send them to landfill, or a polluted Third World village for dismantling?

Dan Gerous
20th Mar 2018, 15:53
If they sorted out the whole country being covered by DAB then we would all have a choice. If all you can get is the FM signal, then that is your only choice, no radio 6, no 4xtra, et al.

VP959
20th Mar 2018, 16:06
As above, no DAB here at all and no plans to make it available, but we can get a reasonable FM signal. I even went to the trouble of installing and external DAB antenna, at significant expense, thinking that it might allow us to listen to the radio when they turn FM off, but even that can't get a hint of a DAB signal, so I may as well have not bothered.

Perhaps someone in the BBC lives in a rural area and has realised that once you turn off main roads or leave high ground DAB reception just falls over.

Good new that they are hanging on to FM, as with pretty slow "broadband" speeds, no terrestrial TV signal, no mobile signal and no DAB signal we were rather wondering whether we were going to have to listen to the radio using the TV, via Freesat.

G-CPTN
20th Mar 2018, 17:48
Although I live in a region where DAB is widely available, the geography prevents me from receiving it as I live down a steep hill with no line-of-sight to the transmitter.
I would need a rooftop aerial with a long pole - and that isn't suitable for portable radio receivers.
My regular listening is transmitted from a location a couple of miles away - on medium wave.
It is the only radio programme broadcast from that transmitter, and 'my' programme isn't available on FM, so I am afraid lest they decide to close-down my local source.

Mallan
20th Mar 2018, 17:55
...and the time signal late.

ExXB
20th Mar 2018, 18:01
Since a couple of years no new FM licenses have been granted here. All existing FM stations are duplicating to DAB+. FM will be gone here in a few years.

Dinosaurs will continue to roam other countries.

Gertrude the Wombat
20th Mar 2018, 18:03
Mr Shennan recognises that "audiences want choice". I thought this was part of the attraction of DAB.
My preferred choice is not to have to throw out and replace several radios.

radeng
20th Mar 2018, 18:24
A lot of keen music lovers complain that the DAB quality is not as good as FM because of the number of multiplexed programmes. Further, although HMG and Brussels would win out because of the amount of VAT accruing from replacing all those old radios, the effect on balance of payments would not be good, because there is very little domestic radio production left. Good for China, Japan and the Far East, though!

VP959
20th Mar 2018, 18:37
Since a couple of years no new FM licenses have been granted here. All existing FM stations are duplicating to DAB+. FM will be gone here in a few years.

Dinosaurs will continue to roam other countries.

The problem here is that they've rolled out DAB radio without putting enough transmitters in place to cover a lot of rural areas. Exactly the same problem occurred when they rolled out terrestrial digital TV.

Like many areas, the pattern of development here is for the settlements to be in valleys, yet the transmitters are all up on top of the high plain above. Lower frequency transmissions, like long wave, medium wave and even VHF FM can just about get down into the valleys, as could the higher powered, lower frequency, analogue TV signal (although with some difficulty).

The advent of higher frequency, lower transmitted power, digital services just removes reception from many rural communities, even though they may be quite close to large conurbations.

When we lost analogue terrestrial TV here a few years ago, the entire village had to apply for planning permission to fit satellite dishes, as it's a conservation area and also inside an area of outstanding natural beauty. In the end planning permission was only granted for low level dishes, not any mounted at or near roof height. Everyone in the village had to switch to satellite TV, whereas in the past they had been able to receive analogue terrestrial TV OK. I would guess the cost to the community of this was many tens of thousands of pounds, just to retain a service they had been using for decades.

The same would have happened had they decided to shut down FM radio, as the much higher frequency DAB signals just don't terrain follow very well.

WestofEMA
20th Mar 2018, 19:12
This should be good news for one of the UK's last FM transmitter manufacturers. Some of you may have heard of them - Eddystone
I was lucky enough to work with them in the mid 2000's to 2015 (several owners) but still manufacturing in the Midlands.
www.eddystone-broadcast.co.uk

As a side, I also had the pleasure to work with Ferrograph Limited, the well renowned tape to tape manufacturer, although they have changed to an entirely different type of manufacturing. LED/TFT/Plasma displays are their realm these days.

vapilot2004
20th Mar 2018, 19:14
Nice job on the thread title, Master Marsh. :ok:

Jetex_Jim
20th Mar 2018, 19:20
Nice job on the thread title, Master Marsh. :ok:
I did wonder if Donald Fagen or Walt Becker had died.

vapilot2004
20th Mar 2018, 19:36
I didn't know until you mentioned it; Becker did die, late last summer, J. Jim.

Lascaille
20th Mar 2018, 19:56
The advent of higher frequency, lower transmitted power, digital services just removes reception from many rural communities, even though they may be quite close to large conurbations.

Purely a design consideration. You should look up 'DRM' - digital radio mondiale. In short, digital broadcasting on the long- and medium- wavebands. A newer standard than DAB, so the more advanced coding algorithms yield better qualities at lower bandwidths. One transmitter would cover the whole of the UK, in fact I believe we transmit from a site near Devon to Brazil.

VP959
20th Mar 2018, 20:11
Purely a design consideration. You should look up 'DRM' - digital radio mondiale. In short, digital broadcasting on the long- and medium- wavebands. A newer standard than DAB, so the more advanced coding algorithms yield better qualities at lower bandwidths. One transmitter would cover the whole of the UK, in fact I believe we transmit from a site near Devon to Brazil.

Sadly there are no plans to introduce such a system for broadcasting in the UK, as far as I'm aware. We are stuck with a relatively old DAB standard that offers poorer performance than FM and is extremely susceptible to impulse interference, that causes fairly long silences in transmissions.

I have a DAB built in radio in my car, but rarely, if ever, use it, as it is frustrating when it just goes silent every few minutes as it loses the signal or gets a bit of impulse interference. There is sometimes a bit if interference on FM in the car, but never enough to make the thing inaudible.

Sallyann1234
20th Mar 2018, 20:24
One reason for the reprieve of FM radio broadcast is that there is no great demand for other users to take over its spectrum.

The UHF TV spectrum is gradually being whittled down because it is useful for cellular radio and earns substantial licence fees for government, but this is not the case with the FM radio band because its propagation characteristics are not suitable for cellular.

Tankertrashnav
21st Mar 2018, 10:01
...and the time signal late

I'm a Radio 4 junkie. As I walk through my house from the kitchen (old Roberts radio stuck on long wave), through the dining room (modern FM radio) to the sitting room (TV on tuned to digital radio channel) it can be quite disconcerting, rather like an echo. Is it beyond the capabilities of the engineers to arrange things so that the time signal is received at the correct time on all systems?

Since a couple of years no new FM licenses have been granted here (Switzerland). All existing FM stations are duplicating to DAB+. FM will be gone here in a few years.


Was it you who recommended Radio Swiss Classic some time ago, ExXB?. If so many thanks, it is a regular late night companion when I am on the computer. No drivelly ads and Lord of the Rings stuff as on Classic FM, and no dreadful jazz or "world music" which Radio 3 inflicts on us at night. Just constant mainstream classics, each with a short intro in German which is improving my fluency in the language!

vctenderness
21st Mar 2018, 10:05
The problem with DAB is it is very hot and miss when out and about.

I use a personal DAB when I walk the dog and some stations are good and some are a waste of time.

In particular Talk Radio UK. I can’t get it at all in the house. On my personal it go’s in and out and is impossible to listen to. On the dab converter in my car it is a no no as well.

I live on the South coast not in some oitmof the way place.

Hussar 54
21st Mar 2018, 10:30
No DAB here at all.

The Government launched the first 'trials' in a few cities just late last year.

https://radiotoday.co.uk/2017/11/france-to-introduce-dab-radio-transmissions/

But no great loss, really, as all my Radio listening comes streamed over the internet - 30,000+ stations from almost anywhere in the world.

ImageGear
21st Mar 2018, 10:43
I would like to think that AM/FM still represents a reasonable strategic alternative to the internet/DAB.

Local AM/FM should still get through to inform the population after the demise of all the space junk.

After all, other than knowing where the food storage areas and the bunkers are located, sombre music may be all one needs.

IG

old,not bold
21st Mar 2018, 16:01
........................ in fact I believe we transmit from a site near Devon to Brazil.On a point of order, what does "Near Devon" mean? You're either in Devon or in somewhere else like Dorset, or Somerset, or (God help you) C*****ll, or out at sea close to the coast. Please elaborate.

radeng
21st Mar 2018, 16:55
'Near Devon' does depend on what you mean by near - to someone in the US or Oz, 'near' can be anything within a couple of hundred miles! The DRM transmissions come from the old VT Communications site at Woofferton, which is just south of Ludlow in Shropshire. VT communications is now owned by Babcock International Group.

Lascaille
21st Mar 2018, 20:10
Is it beyond the capabilities of the engineers to arrange things so that the time signal is received at the correct time on all systems?

It's the intrinsic nature of the system, unfortunately.

Digital TV is a compressed signal.

Most of the compression is achieved 'temporally' i.e. by analysing how the frames are related in time.

The algorithms always start with a reference picture, that's called an I-frame. Your decoder receives the I-frame as a complete picture. Frame zero.

The next picture you see is generated by your decoder from what is basically an instruction list. The basic concept is that the i-frame (frame zero) is divided into a checkerboard of squares, with a separate 'transform' being applied to each square. A transform can be simple angular rotation, translation (sliding), brightness changes, colour changes, 3d-based changes (tilting into or out of the frame) all of which can be combined. The transform list is called a p-frame, because it's a frame that was 'predicted' forwards in time. A p-frame is in general at least 10x less data than an i-frame.

You can see how this easily encodes the natural changes associated with video - the picture changes associated with pans, sweeps, fades and zooms can be encoded almost perfectly by transforms.

Earlier systems used only i-frames and p-frames. Modern systems introduced b-frames. A b-frame is basically a p-frame with the ability to take source data from a wider range of frames, including later frames.

They're a requirement to efficiently encode scenes where new data gradually enters the scene, such as scene-to-scene dissolves, or a windowblind being opened onto a view.

To render a b-frame the decoder must have the source data. The source data could be from a future frame. How can we ensure the decoder has it?

Enter the concept of the group of pictures.

Each group of pictures is self-sufficient. It must contain at least one i-frame, so the b- and p- frames have something to work from. The i-frame doesn't have to be the first frame displayed, but it does have to be the first frame sent. The p- and b- frames follow in dependent order - first those that reference only the i-frames, then those that reference the 'first generation' p- or b-frames, then those that reference the 'second generation' and so on and suchlike.

The typical GOP for high quality broadcast services is 15-25 frames.

The encoder, similarly, has to create the GOP as a unit. It's also got to analyse the 15 or so frames it has in memory to work out which contains the most data that features in other frames (to make the i-frame), to determine the motion vectors and transforms, to decide whether to make a b- or a p- frame... Phew!

There's your delay.

Gertrude the Wombat
21st Mar 2018, 20:36
It's the intrinsic nature of the system, unfortunately.
Only if you don't apply brain when defining the protocol.

The picture/sound can be sent out ahead of time, and there could be a clock in the protocol, with a minimum buffering memory capability as part of the spec, so that when the clock says "it's ten o'clock" the radio or TV can play exactly what it should be playing at ten o'clock 'cos it's been buffering it for a second or whatever's needed. Obviously doesn't work for Big Ben live, but does work for pips or recorded bongs.

Lascaille
21st Mar 2018, 21:49
Only if you don't apply brain when defining the protocol.

The picture/sound can be sent out ahead of time, and there could be a clock in the protocol, with a minimum buffering memory capability as part of the spec, so that when the clock says "it's ten o'clock" the radio or TV can play exactly what it should be playing at ten o'clock 'cos it's been buffering it for a second or whatever's needed. Obviously doesn't work for Big Ben live, but does work for pips or recorded bongs.

DAB broadcasts carry accurate time and signal information via a non-delayed digital channel... Fast Information Channel.

Gertrude the Wombat
21st Mar 2018, 22:56
DAB broadcasts carry accurate time and signal information via a non-delayed digital channel... Fast Information Channel.
BBC don't use it for the pips.

Lascaille
21st Mar 2018, 23:16
BBC don't use it for the pips.

You do know that if your 'locally generated pips' thing was implemented then you'd have the locally generated pips interrupting the broadcast and being either followed or preceded by the 'studio' pips, right?

Gertrude the Wombat
21st Mar 2018, 23:20
You do know that if your 'locally generated pips' thing was implemented then you'd have the locally generated pips interrupting the broadcast and being either followed or preceded by the 'studio' pips, right?
No, I'm suggesting that the broadcast is transmitted early and the timing signal is used to play it at the correct time.

Tankertrashnav
21st Mar 2018, 23:20
Yes I got all that Lascaille

Actually I always was a pretty good liar!

But I'll take your word for it!

Planemike
21st Mar 2018, 23:29
Keep Radio 4 on FM....works for me!!!

jimtherev
21st Mar 2018, 23:59
No, I'm suggesting that the broadcast is transmitted early and the timing signal is used to play it at the correct time.
Not totally sure that would work. ISTR that my older PURE Digital radio and a newer one were not quite synchronised - different decoder maybe? So I came to the conclusion that the delay was generated both at the TX and RX.

Lascaille
22nd Mar 2018, 00:21
No, I'm suggesting that the broadcast is transmitted early and the timing signal is used to play it at the correct time.

By 'the broadcast' you mean just the pips? Or the whole programme? Because I'll explain what I mean.

Oh I read back and saw more detail, did you edit?

You'd lose whatever would have been played just before that point, as your radio would have to abandon it in order to skip forwards and sync up. Could be avoidable by leaving a 10 second 'blank space' just before the top of every hour.

VP959
22nd Mar 2018, 07:46
Keep Radio 4 on FM....works for me!!!

Gets my vote! I'd be lost without my daily dose of The Archers.

Tone
22nd Mar 2018, 10:03
'hot and miss', love it.
We have kitchen radio alongside microwave. Microwave goes on DAB goes off. FM is not the least bit bothered. Checked appliance for leaks - all OK.

VP959
22nd Mar 2018, 10:51
DAB, like digital terrestrial TV, seems unbelievably sensitive to interference, and often just shuts off when there is the slightest bit of it. I have DAB in the car and it's the lack of "graceful degradation" that makes it unusable around here. FM may get a bit of additional background noise in a poor signal area, but it's usually not enough to stop you listening to the radio OK. DAB just goes silent the moment there is the slightest bit of interference or weakening of the signal, and will often stay silent for tens of seconds, maybe even minutes.

If DAB could be engineered to degrade gracefully then I think it'd be a great deal better than it is. I don't mind a bit of increased background noise for a short time, but can't stand just having the thing go silent, as that often means missing key parts of what I was listening to, which is the main reason I stick with FM in the car.

Hussar 54
22nd Mar 2018, 11:23
Maybe it's the DAB radio which we had, although more likely it's our age and the condition of my hearing, but I always find that although DAB transmissions are excellent if the signal is also excellent, the stereo seperation when listening through headphones is still fairly poor compared to a strong FM signal.

Like I said earlier, I now find the best way to listen to radio is by using an old LapTop which has an upgraded sound card ( cost me about € 85, fitted ) which is connected into my hi-fi system ( about € 1000 worth ) and it gives me superb quality sound for 000s of stations via the internet - not just those that broadcast on the local FM transmitter.

Although some stations are only streaming at 64kbps, that's still more than OK for speech such as BBC4, or in our case France Info. But for music stations streaming at 128kbps and 256kbps, the sound quality makes even FM sound like listening to Radio Luxemburg 208 on my little transistor radio as a teenager in 60s.

Add on the option of sites like Spotify for specific artists or music, and stand-alone radios are probably already obsolete.

Gertrude the Wombat
22nd Mar 2018, 12:34
You'd lose whatever would have been played just before that point, as your radio would have to abandon it in order to skip forwards and sync up. Could be avoidable by leaving a 10 second 'blank space' just before the top of every hour.
No, because you'd transmit everything a couple of seconds earlier on digital. The entire channel, all day.

Sallyann1234
22nd Mar 2018, 12:53
No, because you'd transmit everything a couple of seconds earlier on digital. The entire channel, all day.
It would be rather difficult to transmit live broadcasts ten seconds before they actually happened. :D

Sallyann1234
22nd Mar 2018, 12:59
Not totally sure that would work. ISTR that my older PURE Digital radio and a newer one were not quite synchronised - different decoder maybe? So I came to the conclusion that the delay was generated both at the TX and RX.
You are absolutely correct. Much of the delay occurs in the receivers' decoding, particularly with portable sets that have slow processors to reduce battery consumption.

And incidentally the time signal is also delayed on FM broadcasts to some extent, because the distribution network is also a digital multiplex.