For years, many institutions of the world, especially those related with security forces, have used the location of cell phones with which emergency calls are made, in order to locate the telephone equipment and therefore the person that is in trouble.
This active location method is one of the oldest used to establish the correct location of a mobile phone. As currently have begun to implement tracking passive mode, through using GSM networks and the GPS, the satellite position system.
Through the use of GSM networks to locate a cell phone, it is no longer necessary to make a call to said mobile phone in order to geographically locate the device, although it should be noted that the device must be turned on so that the search can conclude with successful results.
The method of location through GSM works very simply, since it is basically set the current position of the phone using a technique called “Triangulation”.
Similarly, most mobile operator companies include, among its client services packs, options that providing device location through GSM technology.
For this, the service is based on various factors and search methods, in order to establish almost exactly the physical location of a mobile phone using the passive technique.
One of the most currently used methods is called Cell of Origin (COO), and as its name implies base their search on including cell ID, and ID Enhanced Cell ID.
The technique that uses the cell ID, allows for remarkable accuracy location, which can roughly locate a mobile phone with an accuracy of up to 200 meters radius in urban areas, up to 2 kilometers in suburban areas, and up to 4 kilometers in rural zones.
In the other hand, the method using Enhanced Cell ID data, enables further improved location accuracy, particularly with respect to rural areas, reducing the radius in approximately 550 meters.
There is another localization method based on the observed time difference, also known as technical E-OTD, an acronym of Enhanced-Observed Timed Difference.
In this case, it is possible to achieve an accuracy of 170 or 650 ft each three base stations, which depends directly on the number of LMUs that are available on the network at that time.
Other methods used very often are “Time of Arrival”, as well “Angle of Arrival” and “Enhanced Observed Time Difference”, i.e. improved time difference estimate, and the system known as “Assisted GPS”.
The latter method, which is performed by triangulating the physical location of the cell phone, through the use of satellites, is one of the techniques implemented today, because of the high accuracy of results provided by this type of technology.
It is for this reason that most mobile phones sold in the market today, especially those mid-range to high, include this fabulous feature among its main options, in order to offer users a secure method to locate the device in case of possible loss or theft of it.