Privately held Data Transmission Network of Omaha started in 1984 as a unit of grain giant Scoular and went public in 1987.

FORBES: Third time's a charm for this little data provider. Or is it?

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.

FORBES: Magazine Article