It would make sense - on paper - to keep PSB1 and PSB2 DVB-T but shift COM4,5 and 6 to DVB-T2 to create some more capacity. However commercially that may kill Arqiva/SDN's business models - but I can't see PSB1 switching to T2 before the COM muxes?
I favour the solution than Ed Vaizey put forwards in 2011 and 12 ...
Mandate all PSB channels to,emit HD only
and coordinate this with the 700 MHz clearance.
Thus does give interesting issues like the decrease in the number of PSB muxes and thus whose they are ( as there is will the COM muxes assuming no vast growth is channels on the platform. )
But it would save many tens of millions pounds a year revenue on double illumination ...
and there he the income from the spectrum auction ( and the half a billion pounds already agreed) to do /offset the cost if the Capex required on DTT
Other objections are the large number of sky SD boxes off contract ..
But there are not that many households without a HD tv and a STB to convert is not THAT expensive ( and the government could give back the help scheme money it grabbed)
Given the any current emissive platform has only say 15 years left and the number of channels will decrease as the martini effect takes place ( any time any place any way )
Given the current Brexit B*****ks .. the degree of clarity from a politician was mind bending
Rkolsen and Markymark gave kudos