17 April 1998

    Date: Fri, 17 Apr 1998 17:54:45 -0400
    From: Dave Emery <die@die.com>
    To: cypherpunks@toad.com
    Cc: cryptography@c2.net
    Subject: Position escrow

    	For those interested in the current state of position escrow
    technology (AKA FCC mandated E-911 emergency call location reporting),
    the  April 1998 Issue of IEEE Communications Magazine is a special issue
    devoted to the subject of locating cellphones and other personal
    wireless devices that radiate rf.

    	This technology, quietly ordered by the FCC, will measure the
    location of a caller accurate to within 125 meters at least 67% of the
    time.  And the industry seems to be moving toward DTOA and other passive
    triangulation techniques rather than making cell phones simply contain a
    GPS receiver. This of course means that the network will be able to
    locate a cellphone whenever it radiates anything at all, rather than
    asking it for its position only under certain emergency circumstances
    such as an E-911 call. And all cell and PCS phones and some pagers can be
    interrogated by the network and commanded to silently respond with a
    registration message without user intervention or knowlage as part of
    the mechanism by which the cell system locates the correct cell site to
    put an incoming call for the phone on.  Thus passive tracking of the
    location of  any cellphone that is turned on with 125 meter accuracy
    will become a feature of most cell and PCS  networks, a feature
    presumably subject to at least some law enforcement access via the CALEA
    mechanisms.

    	And given that the cell and PCS systems will be capable of
    such tracking, is there any reason to believe that law enforcement
    and other more shadowy groups won't find the necessary "terrorist, drug
    dealer, etc" crisis to gain secret access to this capability ?

    --
    	Dave Emery N1PRE,  die@die.com  DIE Consulting, Weston, Mass.
    PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2  5D 27 BD B0 24 88 C3 18

    See also the Special Report on the state and future of wireless technology
    in April 1998 Scientific American.