[Technologist]

If there was money in going HD on the UK DTT platform it would happen!

But it has very chequered past with few other than the PSB and LCN 16 supporting it - and yet is very successful 20 years on!
it also has more government interference in what it does than other platforms...
Although some of this can be good - like the Vaizey plan (2011/2)
which was also good because it mandated the PSB to go HD on ALL platforms and stop SD emission - but being political did not happen -it was meant to be co timed with the 700MHZ clearance

or bad - like to pay to move temporary Muxes carrying HD services to the middle of the Mobile band until someone wanted to use it!
Rather than encourage (with the money wasted) more Muxes to become more efficient by converting to DVB T2 AVC AAC.
as a UK wide one would have been very nice and cheap! (some almost new coders and Modulators being unused!)
With PSB3 changes PSB2 could more easily justify going UK wide ....
But D3&4 have just got a new Regionalised mux !!!! Or itv could take COM1 ....

But as was one of the features of the Vaizey plan using DVBT2 AVC AAC - taking All PSB HD tends to end up with an empty mux.... and is there the income to fund at PSB mux prices - noting that the temporary muxes which were dirt cheap did not have Sufficient takers .... all be it they had limited coverage.
Or if a COM mux converts are there enough broadcasters in the queue to pay for space to cover the costs of conversion.???

If the Vaizey plan had gone ahead that was a time when the platform (emission) was booming... but did require more DVB T2 AVC AAC STB in the population - but as Digital Help Scheme underspent by £400Million that could have been prised out of the consolidated fund which gobbled (LF money) up.

These days being about halfway from Digital Switch On/Over to Digital Switch Off
- people are not looking at the expansion of emission.