The next wave Digital TV and mobile spectrum re-allocation has been planned for sometime and Ofcom now claims to have secured the future of both TV and mobile broadband with a plan that will see the 700 MHz band turned over to the mobile operators in 2022.
This shift is not just an Ofcom initiative, it is something that should take place across the EU and while it will be too late to help with the EU Digital Agenda targets it will happen just at the point where 4G services will be eight to ten years old and suffering the same capacity problems like 3G does now, and we may see more spectrally efficient 5G services running at these speeds (most lab demonstrations of 5G have been in the multi-GHz bands but techniques may help improve speeds even at lower frequencies).
The 700 MHz band is important because you can use less mobile masts to cover the same area and thus it makes it cheaper to serve rural parts of the UK. With the UK now already using Digital TV there should be less disruption from this shift as even today many FreeView devices can cope, Ofcom does estimate some 0.5% (~135,000 households) may need help to change roof-top aerials from 2019 onwards. Of course the idea of a TV aerial may feel very 20th Century by 2022 if IPTV based TV viewing continues growing in popularity.