This, in the end, may be the reason Google is letting go (and could also signal that Cisco will soon sell its own TV set top box unit) as Asian competitors may be turning set top boxes into commodities.
There, a piece of hardware called the concentrator unit plucks the data off a fiber-optic network, reformulates it into a signal at 2 to 30 megahertz and injects that signal onto the power line.
That rather obvious problem accounted for 185 of the cases, with damage to the unit by the offender, problems with the black box in the offender's home, and a weak signal rounding out the technical difficulties.