Basically the three channels will BBC HD, ITV HD and C4 HD and S4C HD in Wales.
BBC HD will continue as it is.
ITV HD will broadcast best of ITV in HD, when Regional and News programmes are being shown on ITV1, other programmes will be shown in HD, it also has an agreement to let out the space for non-peak time.
C4 HD will broadcast in England, Scotland and Northern Ireland, basically just the way it is now on Sky HD.
S4C HD will broadcast in Wales only and will broadcast the best of S4C including Childrens and Sport, alongside Channel 4's own programmes such as Hollyoaks, more like the current Analogue S4C service.
It's set to start in the Granada region next year...
And another stupid decision by OFCOM - but hey, we're used to that by now.
And just as viewers in Wales thought they were rid of the S4C / C4 hybrid, it strikes again in HD.
For three channels it's simply not worth the negative effects it'll have on the remaining SD PSB channels, especially if the BBC lose an interactive stream as a result.
For three channels it's simply not worth the negative effects it'll have on the remaining SD PSB channels, especially if the BBC lose an interactive stream as a result.
I was under the impression that when they move the Mux B BBC Channels onto Mux 1, they'll change the mode from 16QAM to 64QAM allowing the bandwidth to be the same as both Muxes in total, which means they wouldn't really lose any channels.
Might not lose any channels, but the quality might suffer. Until it's in practice it's difficult to say, but it's certain that the picture quality of channels, especially on the ITV/C4 mux, won't get the chance to improve as much as it would have done if a mux hadn't been swiped for HD.
Also, Five and S4C are supposed to be being house on Mux 1 / 2 after DSO too, so effectively they'll be squeezing nearly 3.5 muxes into 2, while the plans upgrade really only comfortably allows for an extra 4 channels on the BBC's mux. OFCOM have also indicated indicated if necessary ITV and C4 might lose a channel in return for their HD slot.
I've no doubt after DSO merging six muxes into five to release one for HD wouldn't be a problem, but OFCOM are going about it the wrong way as usual meaning the core PSB muxes suffer while the commercial ones remain virtually untouched.
I said all this when it was first raised, but for just three or four channels it really isn't worth it and Freesat should have been pushed as the HD option. Personally I think for it to be viable they need at least six channels on offer, including another from the BBC, plus Five HD, Film4 HD and more.
Might not lose any channels, but the quality might suffer. Until it's in practice it's difficult to say, but it's certain that the picture quality of channels, especially on the ITV/C4 mux, won't get the chance to improve as much as it would have done if a mux hadn't been swiped for HD.
My understanding was that the move to 16QAM in 2002 was done to deliver a more robust signal at the expense of capacity at a time when DTT coverage was much less complete. With improved coverage, this would no longer be necessary and 64QAM could return. A 64QAM multiplex 1 should be able to deliver all the SD TV channels in the same quality as they are now split over 1 and B - the only thing possibly to suffer would be the interactive streams.
Am I to take it by these proposals though that OFCOM are simply going to use the move back to 64QAM to squash the main SD DTT service onto 5 multiplexes, clearing space for a dedicated 'HD mux'. In other words, there will be no actual increase in physical broadcast space, only tweaks to deliver more in the same space.
Admittedly I'm no engineer, but with the analogue system gone surely it would be possible to add a 7th (or even 8th) multiplex to main transmitter sites and deliver more capacity this way?
If technically possible, to me there is certainly a business case for doing this - 64QAM modulation + 2 extra muxes could deliver additional capacity on the SD Freeview service, there could still be a dedicated HD mux, and there could also be a pay TV mux if anyone is interested in getting a 'live' pay TV service up and running again (I firmly believe that TUTV as launched would have continued were it able to secure it's own capacity).
As others have said, a service with only 3 channels and no possibility of significant expansion without serious cutbacks to the SD service doesn't seem bothering with. It may well deliver the 3 main FTA HD channels now, but it's not giving any consideration at all to scaling up as more and more broadcasters seek to move to HD. The Freesat HD brand, which with proper marketing could well be just as succesful as Freeview is ultimately going to have much more scope to deliver a complete HD service.
For HD to be viable on Freeview, OFCOM have to actually deliver new broadcast space for these channels to live; simply playing about with capacity that allready exists to squeeze on a few channels with no possibility of adding more will never get the mustard when every other platform has the potential to go beyond that.
For HD to be viable on Freeview, OFCOM have to actually deliver new broadcast space for these channels to live; simply playing about with capacity that allready exists to squeeze on a few channels with no possibility of adding more will never get the mustard when every other platform has the potential to go beyond that.
Hear, hear.
Ofcom have made a total hash of this entire process by refusing to change plans which were made years and years ago, before Freeview became popular and before technological advances. A seventh multiplex would make so much more sense, but Ofcom would rather hold on to the space in preparation for this magical "spectrum auction" that they're planning.
The biggest flaw of all is that anyone with an HDTV now, which generally speaking nowadays are integrated with Freeview, will still have to buy a set-top box as they won't be able to receive the HD signal.
If they're not going to add the extra muxes (which the Digital TV Group claims could allow something like 10-15 HD channels on Freeview) it's just not worth it and they'd be better off settling on the compromise of improving the quality of the SD signal (hey, most folk with a HD TV probably don't realise the difference anyway!)
But as things are it's just a non-starter, especially as by about 2012 most content will be produced in HD anyway and ideally broadcasters would like to be broadcasting most of their channels in HD. What happens then - do they have to start pulling the SD channels to make room, leaving millions of viewers without core Freeview channels unless they upgrade once again - only to find out a few years later their HD box won't be capable of receiving the new improved Super-dooper-ultra-3D-HD signal!
[My understanding was that the move to 16QAM in 2002 was done to deliver a more robust signal at the expense of capacity at a time when DTT coverage was much less complete. With improved coverage, this would no longer be necessary and 64QAM could return. A 64QAM multiplex 1 should be able to deliver all the SD TV channels in the same quality as they are now split over 1 and B - the only thing possibly to suffer would be the interactive streams.
Am I to take it by these proposals though that OFCOM are simply going to use the move back to 64QAM to squash the main SD DTT service onto 5 multiplexes, clearing space for a dedicated 'HD mux'. In other words, there will be no actual increase in physical broadcast space, only tweaks to deliver more in the same space.
There will be 3 PSB muxes available from all 1154 transmitters, and an additional 3 COM muxes only available from the 81 largest sites (80 are in use now). The original plan was for the BBC to have two PSB muxes, with ITV/4 assigned the third. However part of the deal of the BBC having two PSBs, was that C5 (and S4C in Wales) would move from Mux A (COM 1)and share with them, thus being available from all transmitters. That was fine, however Ofcom have now bu g g ered that up by assigning the second BBC PSB mux for HD. that means that all BBC, ITV. 4, 5 and S4C channels will have to be packed into just two muxes. It is certain that some of these services will have to move to the COM muxes, and therefore only be available to 90% of the population, rather than 99.4% for the PSBs.
My understanding was that the move to 16QAM in 2002 was done to deliver a more robust signal at the expense of capacity at a time when DTT coverage was much less complete. With improved coverage, this would no longer be necessary and 64QAM could return. A 64QAM multiplex 1 should be able to deliver all the SD TV channels in the same quality as they are now split over 1 and B - the only thing possibly to suffer would be the interactive streams.
Mux 1 and Muxes C and D will all shift from 2k 16QAM delivering 18Mbs to 8k 64QAM delivering 24Mbs (rendering very early 2k-only receivers obsolete) This should be at roughly the same robustness level - as the guard interval for 8k is much longer than 2k AIUI - because the symbol rate on each carrier is much slower (because there are 4 times as many carriers)
HOWEVER only one of these muxes is a PSB mux - Mux 1 - whereas C and D are commercial non-PSB muxes. Therefore the SD PSB pool goes from Mux 1, 2 and B (18+24+24 = 64Mbs) to Mux 1 and 2 only (24+24Mbs = 48Mbs) - AND Five has to be squeezed in somewhere AIUI as Mux A won't be a PSB mux so won't be as widespread - and thus Five wouldn't otherwise have the penetration of the other PSB channels.
So we'll have gone from the BBC having 36Mbs to 24Mbs for their SD services - a loss of 12Mbs... Who reckons that BBC Three, BBC Four and BBC News will all drop to 544x576 resolution (as BBC Parliament and 301/302 are now - along with all the ITV/C4 stuff other than ITV1 and C4)
I think that ITV and C4 may be forced to shift some of their other services - to other muxes (i.e. the commercial mux space) - and there will be another 12Mbs of this available - as they already use some of this capacity for some of the +1 versions they broadcast?
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Am I to take it by these proposals though that OFCOM are simply going to use the move back to 64QAM to squash the main SD DTT service onto 5 multiplexes, clearing space for a dedicated 'HD mux'. In other words, there will be no actual increase in physical broadcast space, only tweaks to deliver more in the same space.
As explained above - it is potentially worse. Ofcom are moving to a two tier approach AIUI.
Mux 1 = PSB1
Mux 2 = PSB2
Mux B = HD PSB3
These three PSB muxes are to be broadcast from pretty much all the analogue sites - so reception should improve significantly.
Mux A, C and D are non-PSB (COM) muxes and will remain broadcasting just from the current transmitters - as the owners have decided not to invest in the additional infrastructure for greater penetration (it doesn't deliver enough additional viewers to pay for itself)
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Admittedly I'm no engineer, but with the analogue system gone surely it would be possible to add a 7th (or even 8th) multiplex to main transmitter sites and deliver more capacity this way?
The whole point of switching off analogue is to allow the government to sell the free spectrum that is being generated by switching off analogue. Allowing extra muxes would mean less revenue generated through spectrum sale...
DTG have argued for a couple of SFNs (whereby the same frequency is used across the UK) for HD - which would work well with 32k 256QAM DVB-T2 which is going to be used for the HD PSB mux replacing Mux B.
One thing I've wondered about Mux 1 is why is BBC One at a fixed bitrate of 4.6mb? Surely it would be better dynamically stat-muxed? Some programmes BBC1 transmits such as non-fast moving dramas don't really need 4.6mb, more like 2 - 3mb. It's just wasting bandwidth really, IMO.
One thing I've wondered about Mux 1 is why is BBC1at a fixed bitrate of 4.6mb? Surely it would be better dynamically stat-muxed? Some programmes BBC1 transmits such as non-fast moving dramas don't really need 4.6mb more like 2 - 3mb. It's just wasting bandwidth really, IMO.
I think something to do with the fact that it's a regional channel means it can't be statmuxed, and also being the flagship channel really doesn't want to be criticised for poor quality picture which is less important on BBC2 and 3.
