GSM location

The GSM location is a service offered by mobile phone operators that allows to determine, with a certain precision, where a given mobile terminal is physically located.

GSM location may include location-based services that give the actual coordinates of a mobile phone. It is a technology used by telecommunications companies to approximate the situation of a mobile phone, and therefore also that of its user.

Technology

Different methods can be used for GSM location:

• Cell of origin (Cell of Origin), which includes cell ID (Cell ID) and improved cell ID (Enhanced Cell ID).
  • Cell ID: the accuracy of this method is 200 m in urban areas, 2 km in suburban areas and varies between 3 - 4 km in rural environments.
  • Improved cell ID: with this method a precision is very similar to that offered by the Cell ID for urban areas, and in rural environments it offers circular sectors of 550 m.

• Time difference observed or E-OTD (Enhanced-served Timed Difference): the accuracy of this method depends on the number of LMUs available on the network, varying between 50 m and 200 m with an LMU for every 3 base stations.

• Arrival time (Time of Arrival)

• Arrival angle (Angle of Arrival)

• Enhanced Observed Time Difference (enhanced time difference estimate)

• GPS Assistant (Assisted GPS)