Above and beyond: Keeping TV and radio services on air

https://www.arqiva.com/views/blog/above-and-beyond-keeping-tv-and-radio-services-on-air/

Read to the end for ‘Christmas 2016: A story of dedication’

Very dedicated indeed. The post said that the microwave links were damaged during a lightening storm - which must of been bad enough to dispatch a team immediately. The post ended with the following:



But there must of been service if viewers didn’t notice. Couldn’t the back up MUX’s (that’s via satellite) take place if the microwave link didn’t work.

Is microwave connectivity the primary means connecting the Isles and far away transmitter sites? I assume the 50 primary (according to Aerials and DTV) transmitters are the only ones guaranteed to have dedicated fibre connectivity .

Not all 50 sites have a fibre connection, the remote Scottish sites such as Torosay are microwave fed. It would cost a fortune to run fibre to them, particularly for only 17k viewers

http://tx.mb21.co.uk/gallery/gallerypage.php?txid=402

Does the satellite backup carry BBC One and Two Scotland or just the network versions? Or would it be switched to the relevant region if a significant enough tx had suffered a failure and was using the backup?

Pretty sure the transponder at the bottom of this page is it. It's the contents of the BBCs two DTT MUXs. It has all 4 nations of BBC1, but only UK versions of everything else
https://www.lyngsat.com/Intelsat-907.html

Yep - it's basically a kit of parts to create a national PSB1 mux (i.e. without English regional variations) and an (English?) PSB3 mux (but without ITV or C4 regional variations or BBC National variations) - i.e. both BBC licensed muxes,

It contains the BBC 1 Nations in SD (for PSB 1 back up) but only the London/Eng versions for the five main channels in HD (for PSB 3 back up) . Internally within the BBC it's called 'Fatsat'

I can't remember where it is, but I think there is a remote Scottish relay that uses the Fatsat feed as its primary source for PSB 1 and 3. Which of course means no BBC 2 Scotland SD, or BBC 1 Scotland HD. PSB 2 is fed by off air reception of another relay, but the off air feed often drops out owing to fading.

Countisbury on the north Devon cost is a minor relay that is fed by fibre for PSB 1 and 3. It has a long
history of poor off air reception from Mendip

http://downloads.bbc.co.uk/rd/pubs/reports/1987-14.pdf

At DSO, they threw the towel in, and dug in a fibre, though PSB 2 is still off air fed.

I think it's Bruernish

http://tx.mb21.co.uk/gallery/gallerypage.php?txid=1075&pageid=1282

The Fatsat downlink dish is on the ground. The smaller dish mounted on the mast itself is a V-Sat
uplink/downlink dish, used for telemetry. Quite a few relays have these, where the more usual ADSL line is not available or viable.

It's interesting to contrast this with Norway. Over there they have patches of population who can't receive DTT (because of geography and coverage) but some of these also can't receive DSat because of high fjord-side cliffs. To cope with these, they have remote re-broadcasting systems at the top of the cliffs which receive satellite broadcasts and retransmit a low power DTT mux - very similar to what Arqiva do with the Fatsat system - but on a smaller scale.

However rather than have a dedicated satellite distribution feed they effectively have a regular DSat receiver receiving the DTH FTV encrypted DVB-S transponder (including NRK1 in HD) and then this is rebroadcast as a DVB-T mux retaining the DSat encryption. A special CAM is available for IDTVs and set top boxes to receive this and decrypt it. (NRK's conventional DTT broadcasts are FTA unencrypted)

I'm led to believe that the American Sirius XM satellite radio platform has back up terrestrial relays operating
in an SFN with the D-Sat signals to serve urban canyons in the cities ? My only experience of Sirius was a hire car in British Columbia. Reception cut out, under moderate tree cover, and in steep mountainous valleys up Route 99, but I don't recall problems in Vancouver city centre amongst the sky scrapers, so maybe ?

Urban canyons and long road tunnels I believe. It's L-band (like DAB could also be) isn't it?

Yep, 1.4 ish GHz, I might have had a car with a poorly performing receiver, but I wasn't over impressed
with the reception. I'm sure it's great driving across the Nevada Desert, but even in moderately hilly areas it was
poor with too many drop outs. The bit rate/audio quality of some of the channels was laughably bad (far worse than I've heard on UK DAB, (and that's quite a feat !))