From: "Peter Trei" <trei@process.com>
Date: Wed, 8 Oct 1997 22:07:24 +0800
To: cypherpunks@toad.com
Subject: Re: Internet Via Electric Lines?
Message-ID: <199710081351.GAA15055@toad.com>
MIME-Version: 1.0
Content-Type: text/plain



> To:            cypherpunks@cyberpass.net
> From:          Jonathan Wienke <JonWienk@ix.netcom.com>
> I heard on the ABC hourly news that some genius had figured out a way
> to use electrical power lines for data transmission, so that the power
> grid could be integrated into the Internet.  Does anyone have any
> details / pointers?

> Jonathan Wienke

I've heard of two methods; one is to transmit the data as a high
frequency FM signal along the wire. The other is to use power lines
which include an optical fibre. 

Both have problems. 

The FM signal has difficulty going through transformers (there are 
lots of transformers, with the final step-down usually occuring at 
a pole-top near your house). Also, you have to be very careful about
isolating the data output from the power line: an error could send
110VAC into your serial board. I haven't heard of this method being
used on a wide scale, but it might work as a LAN.

The optical method may actually be implemented. Putting a few optical
fibers into a power line is cheap, easy, and widely done. The
idea was originally that power companies could read your electrical meter 
remotely, but the bandwidth available is gross overkill. Thus they 
are also thinking of adding Cable TV, telephony, and data services.

There are still problems. You are basically building a data network 
on top of the power grid, and the topologies don't really match up.
Also, employees have to be trained to splice optical fibers and
install routing equipment, and millions of miles of power lines and
hundreds of millions of junctions need to be replaced or reworked.

There was a rosy article about this in Wired a few years ago. I have
heard nothing since.

Peter Trei
trei@process.com