Telephony over Power Lines (Early History) Carrier-Wave
Telephony Over Power Lines: Early History Mischa Schwartz,
Columbia University Presented, IEEE History Conference, Newark,
New Jersey, August 2007 and annotated since. In this article we
discuss the early history of power line voice communication,
beginning in 1918 and continuing until the early 1930s. We note
that these developments were based on the 1910 demonstration by
Major George Squier of the United States Army Signal Corps of
his "wired wireless" technique for transmitting multiple
telephone channels over one pair of wires. Power companies
world-wide picked up on this carrier-wave telephony technique
for use over power lines, with electrical manufacturing
companies such as GE and Westinghouse in the United States and
Telefunken in Germany, among others, then developing a variety
of systems for this purpose. By 1930, the technique had reached
a period of maturity, with 1000 systems installed throughout
Europe and the United States. Introduction: "