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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.micro
Subject: Re:Integrating a home pc with appliances
Message-ID: <6032@utzoo.UUCP>
Date: Mon, 7-Oct-85 17:28:30 EDT
Article-I.D.: utzoo.6032
Posted: Mon Oct  7 17:28:30 1985
Date-Received: Mon, 7-Oct-85 17:28:30 EDT
Organization: U of Toronto Zoology
Lines: 20

> To do that you'd need an accepted standard for appliance control...
> ... and a transmit medium.  I would suggest carrier current
> AM on the house wires...
> Issues of isolation, security etc. could be solved with some checks in
> the appliances (to keep them from allowing really dumb/unsafe
> operations) and a "home code" that could be some large number of bits
> long to avoid hackage  by friends outside with inductor transmitters
> wrapped around your power lines to "hack your home"... but is this
> latter really an issue or just paranoia?

It's a real issue, because carrier-current signals can and do propagate
to neighboring houses.  There is no magic boundary where the power line
enters your house, or where it hits the pole; normally any signal on the
power line will propagate until it hits a pole transformer or something
similar, and that can cover a number of houses.  You don't need malicious
people with inductor transmitters; an uncooperative neighbor will suffice
to cause problems.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry