Right now we have a mix of standard definition (SD) and high definition
(HD). Currently marketed are 4K televisions with amazing images.
We can stream 4K from commercial sources provided we are prepared to pay for
the fibre-optic connection and streaming source.
Is that it for broadcast TV or is there currently any research currently
seeking to squeeze more out of the available bands?
The BBC did a UHD trial (4K) for the previous world cup, including
DVB-T2 transmission borrowing the COM8 muxes from Crystal Palace and
Winter(?) Hill before they were live.
There are a couple of UHD test channels on Astra 28.2E, and presumably
Sky has commercial channels, my DVB-S2 PCIe tuner found them OK
Also (for certain TVs) They tested a 4K stream of Blue Planet 2 on iPlayer.
Given the number of muxes will be shrinking over the next few years as
phones grab more and more spectrum, I suppose it's unlikely there'll be
any terrestrial UHD services ...