  We study an old but unconventional waveguiding technique based on the use of
overhead bare metal Medium Voltage (MV) power lines as open waveguides and not
as transmission lines. This technique can be used in support of 5G applications
such as backhauling and broadband access in the mmW frequency range or above.
Although the analysis of open waveguides dates back a century or more, very few
communications oriented papers are available in the literature and there is
today no commonly agreed upon channel model. This paper offers a first step in
covering this gap by first solving numerically the characteristic equation
derived from Maxwell equations, then deriving an analytical expression for the
transfer function, and finally reporting for the first time capacity values for
bare metal open waveguides. A channel capacity of 1 Tbps over 100 m can be
achieved using a single overhead Medium Voltage power line, 1 W of total
transmitted power, and the 1-100 GHz band.
