I thought you had to pay the tax for any screen, regardless of where the content comes from?
Source: http://www.tvlicensing.co.uk/check-if-you-need-one which I assume would have the broadest possible definition
"1.3 Note also that “received” means receiving a TV programme as it is being broadcast on TV. It does not include receiving programmes by means of a DVD or the on-demand elements of services such as i-Player."
Meaning that anything that is live, or recorded from a live signal, requires a TV licence - whether or not it came from an over-the-air signal or via an IP service.
But if you consume a catch-up TV service, or watch DVDs, or use Netflix... then you do not need a TV licence.
Aside from the person I know who works at the BBC, no-one I know now has a TV licence, just as no-one I know has a land-line telephone. Modern technology (smart TVs and smart DVD players mostly) have obliterated old style viewing.
The licence is needed for any "live broadcast tv". The equipment used is not relevant; and the source of the signal is not relevant. So someone in England watching French satellite TV still needs a licence.