How To Pinpoint A Mobile Device's Location

The most basic way to determine the location of a cellular phone is by analyzing the signal emitted by your phone. Your phone carrier, and if need be emergency personnel, can get a fairly accurate idea of your cell's current location by measuring the angle of your signal as it comes near a cell tower, by calculating how long it takes to move between numerous towers, and by the strength or weakness of your signal as it comes into contact with various towers.

Your mobile device need have no built-in GPS capability for this sort of estimation to be possible. The major drawback to this method of mobile phone tracking is that the location provided is commonly only a rough area rather than an exact point. In a life and death situation this fact obviously would make all the difference. The FCC currently oversees regulations which require cell carriers to provide at least semi-accurate location data to Public Safety Answering Points (PSAPs) when an emergency call is made from a cell. The location of the caller must be ascertainable to within 50 to 300 meters (1).

A more accurate way to pinpoint the location of a mobile phone is via Global Positioning System technology. Rather than measuring a cell's signal GPS utilizes satellites to pinpoint an enabled cell phone. As mobile devices get smarter they can offer real time driving directions using GPS technology. One drawback to this method is that certain terrain features like skyscrapers, mountains, or dense tree cover can reduce the accuracy of satellites attempting to triangulate the position of a sending unit.

The newest method whereby a cell can be located is through WPS (Wi-Fi Positioning System). Originally pioneered by Skyhook Wireless (2), WPS takes advantage of the ever-growing number of Wi-Fi access points that individuals and companies are installing to allow internet access. Each Wi-Fi point generates a constant signal that reveals its location for up to 200 meters. In urban areas the sheer number of overlapping access points creates a web of information.

When a person logs on their location can then be determined quite accurately with reference to the nearest couple of access points. This system is maintained and updated by sending out specially equipped mapping vehicles that scan for and pinpoint new access points. The main drawback is WPS's sparse coverage in rural areas.