Galileo goes live

> So far, the first Galileo smartphone by Spanish company BQ is already available on the market and other manufacturers are expected to follow suit.

Is Galileo support not present in smartphone SoCs shipping today?

> Galileo is fully interoperable with GPS

What does this truly mean? Does it use GPS-compatible signalling and thus Galileo satellites masquerade as GPS satellites? Is there are separate 'overlay' Galileo stream for additional features?