[Jimbo2022]

They are switching to S2. They are shown as DVB-S for now as they are still in service in DVB-S. Config I believe will be 23000 3/4 DVBS2 8PSK

[Stooky Bill]

Assuming the line up is still the same as the one as I have access to, you're not quite right. There'll be 5 TV services on each transponder (counting BBC3/CBBC and BBC4/Cbeebies as one service)

Interesting that it seems that 45, 46 and 48 will stay as DVB-S for now (hence why they will only have 4 channels for now). Maybe because they first have to negotiate with Astra for a switch to DVB-S2?

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

With DVB-S2 they could switch BBC Two NI and BBC One South from Skys capacity.

You might be onto something there ;-)

[ASnep]

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

They may need to bother SES because on Astra2 DVB-S2 tranponders tend to be wider with a symbolrate of 23000 instead of 22000. But then again if Jimbo is right they will switch and the data in the EPG just reflects what the transponders are looking like now and not how they will look.

[Jimbo2022]

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

They may need to bother SES because on Astra2 DVB-S2 tranponders tend to be wider with a symbolrate of 23000 instead of 22000. But then again if Jimbo is right they will switch and the data in the EPG just reflects what the transponders are looking like now and not how they will look.

A similar situation has happened before but cannot remember when

[Stooky Bill]

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

They may need to bother SES because on Astra2 DVB-S2 tranponders tend to be wider with a symbolrate of 23000 instead of 22000.

Yes, they'll need to know the parameters of the uplink, but as long as the new symbol rate isn't one that takes the uplink out of the bounds of the transponder then they won't have an issue. Changing the roll-off has an effect too, making that smaller makes the carrier effectively wider.

Most of the transponders have a symbol rate of 27.5 so either the BBC have ones that have a smaller bandwidth or they're conservative with them. EIther way 1 extra M/Sym won't make a difference - their DVB-S2 transponders already use that

But then again if Jimbo is right they will switch and the data in the EPG just reflects what the transponders are looking like now and not how they will look.

I'm not sure what you mean. The change to the transponders and the change of the EPG are two seperate processes and impossible to do instantaneously.  

The transponder will have to go off air to make the changes... you can't just change things like symbol rate and modulation type on the fly. Plus the data rate of the new line up has to be correct before going to air with it. 

I'm not how EPG changes work - when they're done (overnight or during the day) and how long they take to react on people's boxes at home - whether a viewer tuned to a service loses it when it is being pointed elsewhere for example. But co-ordinating the two will be tricky, they will want to have the new transmissions up and running for a bit before making the EPG changes, especially where the existing HD service is moving

My guess is that all the SD LCNs on a transponder will be pointed away to the nightlight, then the transponder will close and the changes made. Once that's been on air for a few days the EPG changes will be made to point HD LCNs to that transponder.

[aaron_scotland]

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

They may need to bother SES because on Astra2 DVB-S2 tranponders tend to be wider with a symbolrate of 23000 instead of 22000. But then again if Jimbo is right they will switch and the data in the EPG just reflects what the transponders are looking like now and not how they will look.

Perhaps not, the DVB-S2 transponders have a lower rolloff so actually use less spectrum than the DVB-S transponders despite a larger Symbol rate.

Comparison of 2:

[lovinthetelly]

Assuming the line up is still the same as the one as I have access to, you're not quite right. There'll be 5 TV services on each transponder (counting BBC3/CBBC and BBC4/Cbeebies as one service)

Interesting that it seems that 45, 46 and 48 will stay as DVB-S for now (hence why they will only have 4 channels for now). Maybe because they first have to negotiate with Astra for a switch to DVB-S2?

DVB-S2 is the modulation standard for HD, although DVB-S can he used for HD I don't think it's the done thing.

I doubt they'd need to negotiate with Astra, as long as the uplink is on the right frequency, not putting out too much power and conforms to their technical standards they don't care what is done with it. For the changes to happen they'd need to know as the uplink needs to be cut and brought back up

With DVB-S2 they could switch BBC Two NI and BBC One South from Skys capacity.

You might be onto something there ;-)

As I understand it, South and South West will be among the first to switch. South HD is obviously already live on a Sky-hosted TP, but where will South West HD be? 10818V can't be converted until SW HD is up-and-running.

[ASnep]

The transponder will have to go off air to make the changes... you can't just change things like symbol rate and modulation type on the fly. Plus the data rate of the new line up has to be correct before going to air with it. 

I'm not how EPG changes work - when they're done (overnight or during the day) and how long they take to react on people's boxes at home - whether a viewer tuned to a service loses it when it is being pointed elsewhere for example. But co-ordinating the two will be tricky, they will want to have the new transmissions up and running for a bit before making the EPG changes, especially where the existing HD service is moving

My guess is that all the LCNs on a transponder will be pointed away from that transponder, then the actual transmission will change. Once that's been on air for a few days the EPG changes will be made to point LCNs to that transponder.

I know they need to take them down at least shortly.

But "a couple of days of testing" would mean that people loose access to regional BBC One on satellite completely, wouldn't it? Because where do they point the LCNs of the transponder that is about to change to?

I'd think the BBC would like to avoid such a situation.

[Jimbo2022]

As far as I understand it everything except BBC1 SD (SIDs 6411/6491) are frequency changes effectively

SID 6412 is the BBC2 sustaining service IE what BBC2 HD The rest are single services are can swap to new frequency.

So the national services will switch as well as BBC2. Wales and NI will eventually be switched (for SD viewers). Radio will also be moved over with a transponder change

For BBC1 I think what us meant to be happening is each region that launches once it's on EOG the SD feed will close for that region. At that point the region's that get HD regions will then get the BBC1 sustaining service in SD via SIDs 6411/6491.

The SD feeds stay until early 2024 on one mux. The rest if the BBC muxes are being changed one by one.

So there will be different dates for different regions and therefore there will be times when some SD regions still exist and sone that don't. So there will be a mixed bag at least fir a while.We just don't know the order the changes are happening in yet

Hope that helps

[Stooky Bill]

I know they need to take them down at least shortly.

But "a couple of days of testing" would mean that people loose access to regional BBC One on satellite completely, wouldn't it? Because where do they point the LCNs of the transponder that is about to change to?

I'd think the BBC would like to avoid such a situation.

That won't happen. If you look at Jimbos list of where everything will be and compare it with where everything is now there are no regions that end up on the same transponder in HD as they are in SD (I think) 

They're being done in an order so that by the time one transponder closes the equivalent HD region will already exist. The national services will already have an SD equivalent on air on the nightlight. 

It's not a big bang, it's a big shuffle