GSM & A5

[Ross Anderson]

> Can you or I fix the position of a cellphone user. Not unless you are within
> a few tens of metres of them (in which case your eyes may suffice).

See http://www.cellular.co.za/mobile_location_vendors.htm
and http://www.cursor-system.com/ (our local contender).

Most of these are oriented toward the network operator but some
may allow third-party piggybacking, or could obviously be
developed to do so given a bit of effort

Ross