[Technologist]

With the radio stations there's also alternative ways of listening, such as smart speaker, mobiles, and of course physical radios.

Potentially an advantage would be to encourage users to switch to the HD channel version, whilst making those with older TVs aware that their TV wasn't compatible and needed an external device or upgrading.

This would be useful if they were planning to convert PSB1 to DVB-T2. Considering they've not yet renewed PSB3 it's feasible they might want to move their HD channels onto PSB1 to save costs, leaving just BBC One on PSB3 due to that multiplex's English regions support. Paying whoever then takes over PSB3 to transmit BBC One would presumably be cheaper than the cost of running the entire PSB3 multiplex in addition to PSB1.

Currently we have PSB DTT code and mux
PSB1 BBC A SD installed at DSO say 2010
PSB2 D3&4 SD installed this year 2023 by BT M&B
PSB 3 BBC B BBC FTA HD installed October last year 2022

All are regionalised - PSB2 and 3 use the same coder equipment/Platform
The 2010 PSB 3 coders were redeployed by the BBC to code the HD services on DSAT
and there are plans to move them to the same ATEME Platform like PSB2 and 3.

If the DTT PSB muxes were reorganised to have PSB HD Only "Vaizey plan"
this could be done by a Regional Mux say 180 coder instances
and National Mux say 60 coder instances and UK Wide mux say 20 coder instances
(actually the UK wide mux is fairly empty so need not be needed for PSB!!!)

Other than the large regulatory issues PSB1 could be replaced by a National Mux....
and if PSB3 carried BBC Local radios it becomes the PSB mux for the legacy PSB plus Some Other BBC TV

PSB1 Re-engineered would carry the rest of BBC services and National TV and UKwide and national Radio.
(And a few other channels may be - but that is a great leap regulatory and commercaily)

and PSB2 would just loose three channels but then would not carry any PSB
- which again is a serious regulatory issue ....... and thus can stay SD
It may be commercial issue for D3&4 as there are cheaper way of transmitting some channels
and rather changes their current contracts if it goes UK wide!

But is there a commercial imperative for this ?? The answer is NO
which is why the Vaizey plan was mandation for
PSB to be HD only on ALL platforms at 700 Mhz band clearance (note ALL)
i.e. direct government intervention following the regulatory action which set up PSB 3 at DSO

But this is one of very many scenerios- but as DVB DTT ends in mid 2030s
any changes would need to be done fairly soon to amortize the costs .......
( noting that DSO was funded by the 25 year contracts rather than a normal shorter one)