Another Cellular Vict
Bill Sommerfeld
sommerfeld at orchard.medford.ma.us
Wed Jun 22 06:34:54 PDT 1994
Which suggests a "stealth" phone that randomly dithers its round trip
delay a la GPS selective availability...
Well, I'm not sure how well that would work... The "dither" on the
RTT can't go negative (for obvious reasons :-) ).
Presumably the dither turns a "He's somewhere on this circle" into a
"He's somewhere inside this circle".
If you vary the dither over time, someone trying to track you would
wait for the RTT to hit a local minimum to get the most precise fix.
If the dither introduced by the phone has to be the same for all cell
sites, it gets even easier.
- Bill
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