Fixed-line broadband operators across Europe are rushing to secure wireless assets, whether cellular or Wi-Fi, in order to offer quad play services. The UK’s incumbent, BT, for so long a slumbering giant, has recently been aggressive in expanding its services. It has invested heavily in Wi-Fi hotspots, has a homespot deal with FON, and has gone head-to-head with Sky in premium TV. Now it looks set to extend its reach further, into the consumer mobile space, bringing another competitor to an overcrowded market and harnessing small cells, in its own spectrum, to fend off Sky and Virgin. If these plans, revealed by unnamed sources to UK newspapers, come to fruition, BT would be back in the consumer mobile space for…