SD channels - when does it become viable to replace them?

Never mind the pretty nonsensical description I've conjured up - a thought did pass onto my mind about the future of SD channels.

It is still a popular standard used in the UK of course - thanks to multiple factors and circumstances, but once those are allayed - their days are numbered.

Regions and Nations for terrestrial channels
Currently, BBC ONE and TWO HD are shunted at slightly less prominent slots (depending on area), as is ITV and Channel 4 HD, thanks to regions and nations not being rolled out completely. With rollouts of nations and regions planned for ONE and TWO, and ITV HD (not sure about C4 HD), the SD channels aren't going to be affected, until they are shunted down the EPG with HD swap (e.g Sky does this) and if it's financially unviable to continue. The DVB-T2 switch could also partly influence this, though it's unlikely to happen for a few more years.

Sky's stance on HD channels
Sky sees HD channels as a premium - and many rely on the Sky Sub Club revenue. They've already began to include HD as standard for the Sky Cinema channels and adding them to the Original Bundle would neuter the viability of keeping their own SD channels on air. It's still an additional charge for the Sky Sports channels, though I'd expect it to change over the next couple of years. Commercial broadcasters like ITV, Channel 4 and Channel 5 have the problem of Freeview bandwidth to consider, even with DVB-T2. Their HD offshoot channels rely on sub-club revenue, and would continue to be subscription based until Freeview capacity is there to accommodate them.

What does everyone make of this?

Well look at many freeview channels or UKTV channels there have alot of content which just cant be screened in HD. SO SD will never go.

At the current rate that it's going - there's demand for SD channels to grow on Freeview, especially when multiplex capacity increases. It's also much more cost-effective compared to that of HD channels, which are more expensive to run. Hence why channels such as ITV2, E4, and Dave to name a few have HD offshoots limited to subscription packages only.

Sadly Sky kind of ringfenced HD early on by marketing it as a premium product but I suspect like E4 going FTA was a turning point for many channels (or channel groups) to viewing Freeview and a free to air model as a more viable option for at least some of their channels it'll be purely a commercial decision when HD becomes the norm - i.e. the space is available and there is more to be gained than there is to be lost from any Sky exclusivity deal.

If the BBC ever get round to launching English regions in HD I think that will be the motivation for a HD switchover - they won't want simulcasts in SD and HD of all regions and once transponders and muxes are switched to new standard to transmit HD channels the extra space required isn't that significant prepared to having HD and SD simulcasts.

I do think the number of homes with HD is pretty high now - Sky have issued HD boxes as standard for years and most Freeview TVs/PVRs available have been HD (not just HD Ready) over the last couple of years, though it's only since the beginning of this year that Freeview have made HD/DVB-T2 a requirement on all products carrying the brand.

With regions and nations I'd certainly guarantee that with a DVB-T2 switch, it would be more likely that the SD channels are shut down - the viability of keeping them is absent.

I think this year Freeview has required manufacturers remove their badge/logo from products that are designed for SD. They can still be sold and work but just not "authorized".

Are HD channels really that more expensive to run? I understand the costs to broadcast to Freeview and Freesat would likely be higher but you would be hard pressed to find equipment that's SD only. Here in the US there are certain channels that are only distributed in SD via cable and satellite but when you watch their TVEverywhere (think of SkyGo) feeds and OnDemand its HD. They just run a down converted feed.

I think there are two issues here. I think SD channels are here for a long time to come. What will change, I think is the use of DVB-T2 on more MUXes. There are already SD channels broadcasting using DVB-T2 and the switch would allow more channels, both SD and HD to be broadcast.

Obviously SD channels broadcast using DVB-T2 would only be available using Freeview HD equipment.

Yep, once you have upgraded your equipment and infrastructure the only extra cost is the extra bandwidth to distribute your channel. That's not only the cost of the DTT or satellite carriage but also the circuit to get the channel to whoever is doing that distribution.

Think there are multiple things to consider here :

1. Simulcast of HD services in SD MPEG2. Once the UK has migrated to all DVB-T2, all terrestrial receivers will be able to receive HD and SD channels using H264 compression. That means there will be no SD MPEG2-only receivers, so the simulcasts can stop. As of this month all Freeview branded equipment must be Freeview HD DVB-T2 compatible. (This has been true since Jan 2016 for >32" displays) Effectively any new Freeview device sold now is Freeview HD (suspect this doesn't include old models/stock)

2. SD-only services. Some channels still only show content largely shot in SD, or have budget levels that mean SD is more appealing. (SD is still cheaper in terms of storage, distribution etc.) These will be able to use H264 compression (as the DVB-T2 SD channels currently do) which is a lot more efficient/better quality. There are still commercial reasons to broadcast in SD. Also - if you currently have an SD production and/or distribution infrastructure, the costs of upgrading to HD end-to-end are still not insignificant, particularly if you are sweating assets.