BBC HD to switch to DVB-S2 on 6th June 2011
The high definition (HD) television channels on satellite require a lot more bandwidth (number of bits per second) than the standard definition (SD) ones, as you might expect.
However the additional capacity required is reduced in two ways. First the MPEG-4 compression system is used (rather than MPEG-2) and generally the DVB-S2 modulation system increases the bandwidth of each satellite transponder.
Generally speaking, around nine SD television channels can be carried on a transponder in DVB-S mode, and four HD channels on one in DVB-S2 mode.
For historical reasons, the BBC's Astra 2D transponder 50 has been providing BBC One HD and BBC HD (and also ITV1 HD Merdian South) in the DVB-S mode, and this has used all the capacity on the transponder, because of the lower bitrate.
The changes
One 6th June 2011, the BBC will switch the transponder to DVB-S2. If you watch using Sky+HD, Virgin Media or Freeview HD you will not have to do anything.If you use a branded Freesat box (or TV set), you may need to put it into stand-by mode for 30 seconds on 6th June. If that doesn't work, perform a 'first time installation'.
Update: Some Panasonic Freesat boxes are unable to deal with the change - see comments below
If you are using a unbranded Freesat box, you may find that you also have to do a 'first time installation' to get the channels back.
Some older satellite equipment will not support DVB-S2. If you can't watch Channel 4 HD, then you will no longer be able to watch the BBC HD channels.
Sky HD, Freesat HD EPG issues
Currently BBC One HD cannot automatically replace BBC One in the Sky EPG at position 101, because there are 15 regional versions of BBC One, and only a single BBC One HD 'stream' on the satellite.BBC Two carries four regions for England, Scotland, Wales and Northern Ireland. For a BBC TWO HD to appear in the Sky EPG at position 102, the BBC would need to provide four versions of BBC TWO HD.
All the other BBC channels are national, and have no regional components. BBC Three timeshares with CBBC, BBC FOUR timeshares with CBeebies, plus there is BBC News, BBC Parliament and BBC Alba.
The extra capacity found by moving to DVB-S2 could allow the BBC to provide BBC Three, BBC Four, CBeebies and CBBC channel in HD, and these could be provided in the "usual" EPG slots for Sky HD and Freesat HD users, which would put them on the lower numbered channels nearer the top of the guide.
2:50 PM
@Brianist
I think you may be a bit optimistic for the BBC to move existing channels to HD. Danielle has already said there will not be any new channels till 2013.
I think it is more likley this is for the Wimbledon 3D experiment.
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Trevor Harris: I'm always optimistic. I was really trying just to explain the technicalities involved, rather than BBC policy.
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9:24 AM
Thank you for warning the users, some of whom spoil everything for the rest of us. I for one have no wish to read vulgar and offensive comments not to mention blue language as seen in recent weeks.
Please keep up the good work.
Thank you
R Parkin
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10:06 AM
Will the ordinary Joe Public know about this?
How many will go out and buy a new box because they think theirs is broken.
Or maybe call out an engineer to fix it.
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David: All Freesat HD boxes do DVB-T2, all Sky+HD boxes do DVB-T2, almost all HD transmissions aside from the BBC's use DVB-T2. No one will notice.
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2:24 PM
If your box/TV accepts the change without a hitch, IE require a rescan or reset.
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David: This sort of thing happens all the time with channels moving between transponders, the Sky+HD and Freesat HD boxes are designed to deal with channel reconfigurations.
The only people that might have to do anything are those with 'generic' free satellite receivers.
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8:09 PM
Swindon
my box cogmac (hd-s ci100).i thought was not capable of receiving DVBs2 as its 4 yrs old. but i found out today that on the same menu set up where you enter the frequency and symbol i could also change the DVBS to DVBS2. As my box had in its model number above hds this was a surprise to me. so i noe have ch4 hd and tomorrow i will still get bbc. i hope this will help people that might not know about the fact some boxes you have to change the DVBs/DVS2 YOURSELF
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ARCHIE's: mapA's Freeview map terrainA's terrain plot wavesA's frequency data A's Freeview Detailed Coverage
ARCHIE: Thanks for that. All equipment that can decode MPEG4 should be able to do DVB-T2.
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