From: lefty@apple.com (Lefty)
Date: Tue, 21 Jun 94 09:11:15 PDT
To: cypherpunks@toad.com
Subject: Re: (None)
Message-ID: <9406211610.AA28536@internal.apple.com>
MIME-Version: 1.0
Content-Type: text/plain


>> I was on a trip out of town a while back... as soon as I crossed
>> into another cellular network boundary, I got a call from the
>> provider's sales droid, telling me how to use their service. They
>> _are_ tracking individual phone movement, IMHO.
>     Not just IMHO... They are tracking individual phone movement. I know
>this for fact. What happens is this: When you are out driving, your phone
>is constantly checking the local zone for strength. When the strength goes
>down, or signal quality is too low, it scans for a new zone. Then it "logs
>in" to the new zone while "logging out" of the old zone.
>
>     Big cities, like LA, have ALOT of zones, none of which are all that
>big. By knowing which zone one is in, one is leaving, and one is entering,
>it is very easy to determine where someone is, especially if that zone
>tracks along a major highway. Then, it's just a matter of time until he's
>found.

Forgive my ignorance, since I've always viewed cellular phones as being
overpriced toys, but if the cellular network _didn't_ track the location of
a given phone how could it route incoming calls to it?  Some friends who
were visiting from New Mexico this weekend told me they had to inform their
service provider of where they were going to be so they could receive calls
on their cellular phone.

We've played with wireless mobile networking around here, and routers need
to keep track of individual nodes as they move around.  Are cellular phones
different?  Am I missing something here?


--
Lefty (lefty@apple.com)
C:.M:.C:., D:.O:.D:.