Ride the Lightning
Cybersecurity and Future of Law Practice Blog
by Sharon D. Nelson Esq., President of Sensei Enterprises, Inc.
How Cell Phone Triangulation Works
January 3, 2013
Ever wonder how law enforcement knows where someone is without having access to surveillance video? More than likely, they are using information from the cellular carriers to locate the suspect via their phone location. The process is fairly straight-forward, but the man on the street rarely has access to the information in order to determine a cell phone’s location. What you need is the location of the cell towers that can “see” the phone. The tower with the strongest signal is the one that the phone will utilize, but other towers can also “see” the phone as it moves and may eventually “jump” to a new tower.
First you locate the tower with the strongest signal and draw a circle that depicts the coverage area for the tower. You know that the phone is somewhere in that circle. Locate a second tower that can “see” the phone and draw a circle showing its coverage area. Now you know that the phone is located somewhere in the intersection of the two circles. Continue to add circles for all the towers that can communicate with the phone. The intersection of all the circles helps narrow down the actual location of the phone. This is not a very exact science but you can generally locate the phone within 100 meters or less.
GPS location data from the phone itself (being transmitted to the carrier) and connections to known WiFi networks narrow the location of the phone even further. Most people don’t seem to know that “Big Brother” could be watching and tracking our location by using our cell phone information.
If you think the law will protect you from this kind of surveillance, you’re in the wrong century.
Thanks to John for this guest post from our list of most frequently asked questions!
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