What does your mobile network operator know about your location?
Background
If you have ever watched any spy films you might have wondered how did the government agencies or police located somebody’s cellular phone. Despite the fact that it usually takes a magical 60 seconds, it is possible to get the location of a mobile phone with quite a good accuracy. In the real word it requires cooperation with the mobile network operator (which such agencies of course have :>). Getting back on topic, the question is How much does your operator know about your location?
In this post I will focus on GSM communication, which still is the most popular technology. There are several GSM operating frequency bands, i.e. P-GSM 900, E-GSM 900, DCS 1800 and PCS 1900 (these are the most popular). One important thing is that there are always two sub-bands – one for uplink (toward BTS) and one for downlink (toward mobile phone). Example: P-GSM’s uplink band is 890-915 MHz and downlink is 935-960 MHz.