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.