From: karn@qualcomm.com (Phil Karn)
Date: Mon, 10 Jan 94 19:31:38 PST
To: pat@tstc.edu
Subject: Re: Crypto not being used where needed
In-Reply-To: <9401101936.AA03275@tstc.edu>
Message-ID: <199401110330.TAA07277@servo.qualcomm.com>
MIME-Version: 1.0
Content-Type: text/plain


There are several commercially available "RF service monitors" with
option modules specifically designed for AMPS (the North American
cellular standard). Manufacturers include IFR, HP and Marconi.

Among many other things, these monitors can be programmed to monitor
cellular access channels. Whenever someone nearby hits the SEND key on
their phone, the monitor instantly displays the called number, the
user's MIN (phone number) and ESN (electronic serial
number). Furthermore, it can be told to automatically follow the
conversation channel assignment message and any subsequent handoff
messages.

Or the unit can be programmed to monitor the forward paging link for
pages (land-to-mobile) calls directed to any particular mobile. When a
page is found, the unit can again switch to the appropriate
conversation channel and follow the conversation through any
subsequent handoffs. You do, of course, have to remain physically
close enough to the mobile in question to be able to hear the same
cell sites it is using.

As a manufacturer of cellular phones, we have legitimate need for such
units in testing our phones. We had one of these units in house a
while back and I had a chance to play with it. I can attest to its
effectiveness. It's not cheap, of course, but if we can afford one,
than so can any motivated government agency.

Phil