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harshy6,214 posts since 24 Mar 2001
The HD is really poor 3mbps HD for a prized event like Wimbledon, the world feed at 7e is 13mbps!

The BBC Sport graphics don’t even match the host broadcasters superior graphics, at least with the previous graphics it wasn’t quite as obvious what was Bbc and which part was IMG.

Sorry, 3mbps where, on what platform?


Others will have more experience, but 13mbps sounds on the low side for a world feed, one that will end up being compressed at least once more before it reaches viewers.

Dsat 28.2e I’ll put the bitrate calculator on the world feed tomorrow again.
noggin14,546 posts since 26 Jun 2001
http://www.digitalbitrate.com/dtv.php?mux=10847&pid=6941&live=69&sec=0&lang=en BBC One HD on 28.2E averages around 4.5Mbs with peaks of up to 17Mbs.

http://www.digitalbitrate.com/dtv.php?mux=BBCB-PSB3&pid=17540&live=9&sec=0&lang=en BBC One HD on PSB3 DVB-T2 is similar.

Sure - statmuxing can push channels below their average - but that's what statmuxing is for. (The court wide shot on Wimbledon will compress very well)

That said - the UHD HDR MPEG DASH iPlayer Centre Court stream is 7Mbs 720p50, 10Mbs 1080p50, 16Mbs 1440p50 and 36Mbs 2160p50 - and that's using HEVC/h.265 which is more efficient than the h.264/AVC used on DSat and DTT in the UK (though the HEVC encoders may not be as advanced yet)...
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commseng262 posts since 8 Dec 2016
London London
The HD is really poor 3mbps HD for a prized event like Wimbledon, the world feed at 7e is 13mbps!

Others will have more experience, but 13mbps sounds on the low side for a world feed, one that will end up being compressed at least once more before it reaches viewers.

A fairly standard rule of thumb is that for the UK broadcasters, a 18MHz satellite slot is booked for the main feed.
That should give you (with normal modulation parameters) around 31Mb/s.
A backup at a cheaper 9MHz slot will give you 15.5Mb/s, and it sounds like this is what is being used here.
If you add audios to that (plus other data) then you can drop to 13Mb/s - just Dolby audio will take 2Mb/s.
When Dolby atmos is added to a UHD feed, then you end up booking a 27MHz slot to keep the vision acceptable.

I'd agree for a world feed that 9MHz sounds a little thin for HD - you can usually buy ad hoc slots of 4.5, 9, 12 or 18MHz quite easily from the usual leaseholders.
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thegeek5,003 posts since 1 Jan 2002
London London
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.
UKnews838 posts since 26 Apr 2011
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.

Satellite being the second reserve / emergency path has been the connectivity arrangement at other major sporting events for some time now. Wimbledon is definitely fibre main, not sure beyond that.


thegeek- I don’t think the main path from Wimbledon has ever been on satellite?
dosxuk4,216 posts since 22 Oct 2005
Yorkshire Look North (Yorkshire)
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.

Satellite being the second reserve / emergency path has been the connectivity arrangement at other major sporting events for some time now. Wimbledon is definitely fibre main, not sure beyond that.


thegeek- I don’t think the main path from Wimbledon has ever been on satellite?


Used to be microwave linked to crystal palace IIRC
noggin14,546 posts since 26 Jun 2001
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.


Yep - I think the host broadcaster court feeds are all carried over fibre to IMG at Stockley Park who handle forward distribution to at least some rights holders? I think this is a Hypermux point for EBU FINE connectivity?
commseng262 posts since 8 Dec 2016
London London
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.

Satellite being the second reserve / emergency path has been the connectivity arrangement at other major sporting events for some time now. Wimbledon is definitely fibre main, not sure beyond that.


thegeek- I don’t think the main path from Wimbledon has ever been on satellite?

I would agree that Wimbledon used to be via microwave link into both Crystal Palace and also Swains Lane to provide diversity.
Plus when interactive started, the sheer number of circuits required both the London terminals to provide the link reception and circuits into TVC.
noggin14,546 posts since 26 Jun 2001
The BBC's main path out of Wimbledon is almost certainly by fibre - if they're skimping on a satellite contribution it'll be a "we hope to not have to use this but at least it'll keep us on air if we do" budgetary choice.

Satellite being the second reserve / emergency path has been the connectivity arrangement at other major sporting events for some time now. Wimbledon is definitely fibre main, not sure beyond that.


thegeek- I don’t think the main path from Wimbledon has ever been on satellite?

I would agree that Wimbledon used to be via microwave link into both Crystal Palace and also Swains Lane to provide diversity.
Plus when interactive started, the sheer number of circuits required both the London terminals to provide the link reception and circuits into TVC.


Yep - it switched to fibre (ISTR IP over fibre but I may be wrong?) quite a while ago now?
commseng262 posts since 8 Dec 2016
London London
10 years ago there were 24 Mb/s circuits supplied by Genesis, they were SD reserves.
The main HD circuits were radio link into CP at 69Mb/s with Dolby E sound and also carried an SD circuit for Children's and News.
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