Feeds to Irish Channels

Sorry noggin encrypt yes it’s only the last two Eurovisions(iirc) that have been encrypt on satellite, it was previously fta but in HD 4:2:2 and that really was a test for my graphics card.

Don't know about the path from Red Bee to the BBC's Coding and Mux operation - but the circuits for all the ITV internal network are HD-SDI over IP AIUI, with decoding to HD-SDI for routing in the HD-SDI domain at two switching centres, before re-encoding to IP.

Cable companies? Think you mean cable company... Virgin Media are the only real cable operator in the UK. AIUI they get an uncompressed feed - but not sure what the carriage medium is - and I may be wrong.



That's not the case. Those broadcasters who contract to handle their own free-to-air uplinks rather than outsourcing to Sky - like the BBC, ITV, C4 etc - and who want them on both platforms - generate transponder muxes that carry both Freesat and Sky specific platform data (Sky and Freesat use different EPG, subtitling, digital text etc. standards) so that they are compatible with both receivers. This will include needing data feeds to and from Sky and Freesat for some of this data.

It's not that Sky program their receiver to take Freesat feeds, any more than Freesat program their receivers to take Sky feeds (Sky uplink services that they make available on Freesat too), broadcasters and uplink operators who wan their broadcasts to be available to both platforms must carry platform specific data for both platforms, in co-operation with both platforms.

It's not Sky making their receivers compatible with 'Freesat feeds'

They don't, if anything it's the other way round.


The transmissions for Sky and Freesat customers are the same, and the main metadata accompanying them is for Sky boxes. However Freesat add additional data to provide the equivalent for their customers. This is put elsewhere in the stream and so is ignored by Sky boxes. It does mean though that a multiplex such as one of the BBC's has a network ID of 'BSkyB' when seen on a generic receiver

This is of course because Sky's platform was there first and Freesats then had to be made to work alongside it.


Edit: Noggin beat me to it, knew I should have skipped my bowl of cereal...

Correct me if I’m wrong that in layman’s terms it sounds like the companies BBC, ITV and C4 that do their own uplinking add additional data so it will be Sky compatible. And that each regional feed is only uplinked once for service between Sky and FreeSat.

All the various broadcasters are responsible for uplinking their channels, either themselves or via a third party like Arqiva or Globecast.


Though I'm pretty sure that it's only the BBC and Sky who do their channels in-house


My understanding is that the Sky 'data' is the default, standard DVB metadata and the Freesat 'data' is additional


There's no duplication in uplinking channels, Here's a list of channels on the Astra 2 cluster:
https://www.lyngsat.com/Astra-2E-2F-2G.html

Sky do also provide the third party uplink services for broadcasters to use. I believe they offer some broadcasters the complete package of EPG carriage, encryption and uplink as a combined service.



Both Sky and Freesat use standard DVB data for the channels themselves, although currently two different subtitles standards have to be carried as Sky uses the older DVB-TXT standard (aka teletext) whereas Freesat uses the newer DVB subtitles standard.

Interactive services as stated are different for both as Sky uses OpenTV whereas Freesat uses MHEG (possibly moving to HbbTV), so the broadcasters on both who use interactive services (e.g. the BBC) have to carry two services.

I believe transponders carrying services on the Sky EPG (all of them essentially) have to also carry a proprietary data stream provided by Sky, which ensures Sky boxes continue to receive things like EPG changes, subscription change information and software update information regardless of what channel they're tuned to. Not sure if a similar thing is in place for Freesat, it wouldn't surprise me if there is.

Sky use a proprietary EPG, Freesat use a different proprietary EPG. Neither of them use the DVB Standard EPG. They both use standard DVB Now+Next though.

I believe both Sky and Freesat use standard, but independent, 'bouquet' data feeds for their receivers to map channel line-ups regionally.

The BBC were uplinking to Sky (initially encrypted Free-to-view, then unencrypted Free-to-air) before Freesat launched as a platform, and Freesat had to ensure anything they required broadcasters who were on both on their platform, and Sky's, to do caused no issue to Sky boxes.

I also believe Sky require (or required) anyone not uplinking their services using Sky's uplink services (i.e. not contracting Sky to uplink) to sign an indemnity with a pretty hefty financial penalty, to ensure they wouldn't cause interference to the Sky platform - and this was increased if the uplink also contained Sky-compatible digital text/interactivity.

C4 and ITV don't do their own uplinking AFAIK - but they may contract it out to someone other than Sky (such as Arqiva, Globecast etc.). There may be a mix - ITV2/3/4HD (but not SD) are pay-TV on Sky, as are All4/More4/Film4 HD (but not SD). It is possible that Sky uplink the pay-TV stuff and someone else contracted directly by ITV or C4 uplink the FTA SD and HD stuff. (Sky have done deals to provide uplinks in exchange for exclusivity and these services aren't on Freesat or Freeview HD as a result, though they may be on pay-TV Virgin cable)

The BBC used to do their Astra uplinking in house, then when they sold the department that did it to Siemens, I believe Siemens-then-ATOS continued to do it (with some services upland via Arqiva also at one point), albeit from facilities at BBC-owned sites.

Some of the services the BBC outsourced to ATOS (renamed bit of Siemens) have now been brought back in-house to the BBC - uplinking may be one of them.

Whoever is doing the uplinking - whether it is the BBC/ATOS, Arqiva or Sky - they will be adding Sky and Freesat platform-specific data as required.

There are major differences between the platforms in EPG, subtitles and digital text standards - meaning you need to simulcast data in both formats if you are on both platforms, but the platforms are designed such that these simulcasted data streams can be within the same transport stream on a single uplink and don't require duplication of video and audio feeds (which are the expensive bits)

It was insourced, although just for the domestic services on Astra.

Explains why the HD lacks the crispness of Sky’s HD services.

Why? If Sky handled the uplink that wouldn't change the picture quality significantly. The quality is largely dictated by the number of services per transponder - Sky handling the uplink wouldn't mean fewer services per transponder, that would be a decision taken by the BBC. (It's conceivable Sky have different quality encoders I guess...) Similarly the modulation approach taken.

I think 1998 to 2003 (when the Beeb were encrypted on Astra 2A/B) the uplinking was outsourced
to NTL at Crawley Court (Arqiva in today's money) ? When they went unencrypted on Astra 2D, (and also added all the BBC 1 English regions) then it was 'insourced' to the teleport they built by the W12 East Tower ?