GSM stands for Global System for Mobile Communications, originally Groupe Spécial Mobile. It is a standard that describes the protocols of communication in second-generation (2G) digital cell phone networks. This standard was developed by The European Conference of Postal and Telecommunications Administrations (CEPT).
CEPT was created in 1959 and is a coordinating organization of telecommunications and postal services in Europe. The acronym for CEPT, just like the acronym for GSM, was derived from the French version its name.
GSM is a cellular network. This means that cell phones in the network connect to the network by searching for cells in the immediate proximity to them. There are five different cell sizes in a GSM network: macro, micro, pico, femto and umbrella. Marco cells are cells with an antenna on a building, above rooftop level. Micro cells are the cells in which an antenna doesn’t go above rooftop level and stays around average rooftop level. Micro cells are usually used in cities and urban areas. Pirocells cover a diameter of a few hundred feet and are mostly used indoors. Femtocells connect to the network via an internet connection. Umbrella cells cover areas with smaller cells to make sure that there’s coverage in the areas between those smaller cells. The radius of cell coverage depends on antenna height, gain and surrounding conditions.
GSM Standard was first used in Finland in 1991. It is now the default global standard of mobile communications. GSM networks have over 90% market share and operate in over 200 countries.
Is it possible to track a GSM phone? The answer is yes. Here is how: every GSM device knows the information about the cell it is currently communicating with. If a cell phone uses Google Maps Mobile, then it is possible to identify its location even if the phone doesn’t have a GPS unit in it.
Here’s how it’s done: Google knows the location of antenna towers used in the GSM network. It is possible to install a code in a cellphone that will communicate all these pieces of information to another party: GSM network cell information and location of antenna towers. This can be used to track a phone.
Obviously, this is not an exact location phone tracker method and it’s not as accurate as using a GPS sensor, but it still can get really close to an actual phone location. On a 2G network the accuracy is around 0.5 of a mile. With 3G networks it is possible to get accuracy of around 100 yards for phones without built-in GPS trackers.