Path: utzoo!attcan!uunet!lll-winken!sun-barr!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!sdd.hp.com!hplabs!hpda!hpcupt1!hprnd!pat
From: pat@hprnd.rose.hp.com (Pat Thaler)
Newsgroups: comp.dcom.lans
Subject: Re: Motorola wireless lan?
Message-ID: <2230119@hprnd.rose.hp.com>
Date: 29 Oct 90 19:05:37 GMT
References: <418@bartal.CRLABS.COM>
Organization: HP Roseville Networks Division
Lines: 30

> >---begin unauthorized quote from WSJ---
> > "....a new method for sending data within buildings using
> >digital radio transmission......based on several components,
> >including an omnidirectional antenna, a miniaturized digital
> >transmitter and receiver 
> 
>    Sure hope nobody uses telnet or FTP on a LAN like this. It sounds
> *far* too easy to eavesdrop on. I hope I'm missing something here ...
> whst is it?
> 
What you are missing is part of the nature of spread spectrum.  Rather
than transmitting on one frequency, the signal hops around between
several frequencies at a very fast rate.  To receive the signal,
the receiver has to know the pattern.  A receiver listening to just
one frequency will just hear noise.  In theory, several networks
could operate in the same spectrum area with different codes without
interfering with each other.

This seems to eliminate the threat of a casual listener eavesdropping.
I'm not sure how hard it would be for a determined eavesdropper to
crack by trying different patterns or such.

I would agree with much of what Kent posted.  I believe that spread
spectrum is a secondary use on much of the spectrum space alloted
to it and as such must not interfere with the primary use.  The
advangages are: for low power spread spectrum in certain bands
you don't need a site license from the FCC, it is more immune to
noise, it can't be casually overheard.

Pat Thaler