Digital Switchover - Announcer confusion!

[Dave2002]

I thought I'd steal a title similar to the one Gordon has posted elsewhere - eye catching!

This morning, at 9.45am, the R4 announcer seemed to get confused, and mentioned that LW and DAB would have the Daily Service. In fact it didn't, and neither did FM, both carried on with the Book of the Week reading common at that time. I assume that the Daily Service was on LW.

Yet I discover on searching for details of the Service:

The Daily Service is available on a Radio 4 DAB side channel which is automatically made available about a minute before the programme begins.
After tuning to Radio 4 DAB, select "Daily Service" (from your display) with the tuning wheel and press the selector button.

On some radios the side channel can be stored on a preset button and once it is stored there you simply need to press the preset. We recommend choosing a well established brand of DAB receiver.

I wonder how many of us know or knew about DAB side channels?

I was surprised at the announcer - though this has perhaps come clearer now - I thought he'd made a mistake.

Perhaps this should be on the Techie Thread. Or somewhere else? I'll duplicate the post on the Techie thread and the mods can decide.

[french frank]

Very interesting (sorry, didn't read through to the end before deleting the Techie version - but it's better here, I think). I know nothing about anything but hadn't even heard of DAB 'side channels'. How is it not possible to have a Radio 3 side channel? Or is there one? Alternative Breakfasts?

[Dave2002]

Very interesting (sorry, didn't read through to the end before deleting the Techie version - but it's better here, I think). I know nothing about anything but hadn't even heard of DAB 'side channels'. How is it not possible to have a Radio 3 side channel? Or is there one? Alternative Breakfasts?

I didn't know about this at all.

Actually in the end the Techie version I posted was slightly different - I'll see if I can remember the edits. Firstly, I have to say that on reflection the announcer didn't actually sound confused or flustered - it was this listener who was - as I'd never heard of this. Probably would have been weird if the announcer had to say something like "The Daily service will be available on DAB, er, er, a DAB side channel, which may not be available to all of you out there with DAB sets, but some of you with new ones and special buttons tuned to (state name of channel) may be able to get it if you press the correct button, which no doubt you will have read in the set manual, or also on LW ...." that would have got everyone confused!

ff: If by any chance you have a digital bin where you put my original/edited post on the Techie thread, you could see if there were any more significant points raised. I know I tidied it up over a couple of edits. Anyway, glad you decided it might be useful.

[french frank]

ff: If by any chance you have a digital bin where you put my original/edited post on the Techie thread, you could see if there were any more significant points raised. I know I tidied it up over a couple of edits. Anyway, glad you decided it might be useful.

I'll repost it - sorry, didn't notice the differences.

[french frank]

Dave2002's original post, with apologies:

I thought I'd steal a title similar to the one Gordon has posted elsewhere - eye catching!

This morning, at 9.45am, the R4 announcer seemed to get confused (to me, though in fact he didn't sound flustered), and mentioned that LW and DAB would have the Daily Service. In fact it didn't, and neither did FM, both carried on with the Book of the Week reading common at that time. I assume that the Daily Service was on LW.

Yet I discover on searching for details of the Service:

The Daily Service is available on a Radio 4 DAB side channel which is automatically made available about a minute before the programme begins.
After tuning to Radio 4 DAB, select "Daily Service" (from your display) with the tuning wheel and press the selector button.

On some radios the side channel can be stored on a preset button and once it is stored there you simply need to press the preset. We recommend choosing a well established brand of DAB receiver.

I wonder how many of us know or knew about DAB side channels?

I was surprised at the announcer - though this has perhaps come clearer now - I thought he'd made a mistake.

Perhaps this should be here on the Techie Thread. Or somewhere else? This is a near duplicate, with slightly more details, of a similar post on Platform 3, and the mods can decide.

[Dave2002]

No need to apologise - I see now that there wasn't much extra, apart from my comment about the announcer not being flustered.

Now how many of us knew any of this? What's it all for? Are there any other "side-channels" for other BBC stations, and if so, what are they used for?

[Eine Alpensinfonie]

So what do they call this particular side-channel? It can't be Radio 4 Extra (like Radio 5 Sports Extra) as Radio 7 has become that.

Radio 4 Extra-Extra maybe?

[Gordon]

This side, or secondary, channel business confuses engineers as well!! It was conceived during the development of the DAB spec [the basic idea of Service Information - SI - comes from other, earlier services developed during the 80s] so that generic service types could have linked sub-services that are derivatives and so belong in a family or are non-audio/data services associated with the audio - a kind of "Red Button" for radio. A typical example is regional opt outs or variants. Another is a service that is intermittent, or perhaps different language versions. R1, R2 and R3 are services that don't normally need to use these side channels because they don't have regional or other variants. Most commercial national and local services don't either. R4 and R5 are subdivided from time to time with different versions on FM and MW & LW.

In principle therefore DAB can carry all the variants of a given service using different but linked stream addresses in the SI tables - this duplication consumes valuable data capacity in the process of course. As long as your receiver knows about the addresses it can acquire them but of course it has to be tuned by the user at least once to the service variant, when it is present in the multiplex, to get the address. When a secondary service closes down a receiver should automaticallly go back to its linked primary service which is permanent. The detail is in EN 300 401 under secondary channels but it's described in complicated language - you have been warned.

[Dave2002]

There was no mention of DAB in the run up to the Daily Service today - on FM, and my guess is that they didn't splice in a few seconds extra to mention the DAB option on the DAB service. We could run FM and DAB more or less side by side on R4 in future at about 9.44am, to check that the announcements are the same.