On Mon, 10 Feb 2014 11:07:09 +0000, John Rumm wrote:

(whether you would argue an optical fibre is broadband or not is another
matter!)

It could be some of the higher speed fibre connections use more than
one laser frequency (aka carrier), but then you are probably talking
silly data rates like a few Tbps... B-)

GPON uses two down a single fibre but in opposite directions.

Of course the vast majority saying that they have "fibre broadband"
haven't they have VDSL with the local head end fed by fibre. I reckon
all this crappy FTTC will come home to roost in ten years or so. When
streaming multiple channels of HDTV at sensible bit rates (10 Mbps or
more) becomes the norm, rather than the barely better than SD 2.5
Mbps or so that is used at present.

--
Cheers
Dave.