A system and method to collect data related to the geographical location of a mobile station communicating with a GSM network and to use the location related data to determine the geographical location of the mobile station. A tap is place in an Abis link between a base station and a base station controller, the tap providing a copy of a signal carried by the Abis link. The copy signal is routed to a protocol analyzer that extracts location related data from the copy signal. A location processor uses the location data to determine the geographical location of the mobile station. The geographical location data is used by a data analyzer to provide location based services, such as estimating traffic intensity and speed of mobile stations.