Mobile phone tracking is a
process for identifying the
location of a mobile phone,
whether stationary or moving.
Localization may be effected
by a number of technologies,
such as using multilateration
of radio signals between
(several) cell towers of the
network and the phone, or
simply using GPS. To locate a
mobile phone using
multilateration of radio
signals, it must emit at
least the idle signal to
contact the next nearby
antenna tower, but the
process does not require an
active call. The Global
System for Mobile
Communications (GSM) is based
on the phone's signal
strength to nearby antenna
masts.
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