Cell Global Identity (CGI) is a standard identifier for mobile phones cells, providing means to geographically locate connected mobile phones. If a cell phone is connected to a GSM network then the position of that particular cell phone can be determined using CGI of the cell which is covering that cell phone. There is a series of related technologies that were developed based on CGI that enhances the location precision: Cell Global Identity with Timing Advance (CGI+TA), Enhanced CGI (E-CGI), Cell ID for WCDMA, Uplink Time Difference Of Arrival (U-TDOA) and Any Time Interrogation (ATI), and the high accuracy terminal based method Assisted Global Positioning System (A-GPS).[1]
