This wiki page provides definitions of key words often used for Cell ID GSM tracking.
A unique number used to identify the GSM base transceiver station that the phone is connected to.
LAC - Location Area Code
A 16-digit fixed length code that identifies the phone's location area within a GSM public land mobile network.
MCC - Mobile Country Code
This is a unique number for the country with the GSM net the phone is currently connected to.
More details can be found here.
MNC - Mobile Network Code
This number is used to uniquely identify the GSM network operator in combination with the MCC the phone is currently connected to.
Examples in UK:
A measurement in the OpenCellID context is a GPS position where the radio signal of a GSM base station has been received. If measurements of the same base station have been received at different places, then the average of all GPS latitude values and the average of all GPS longitude values is calculated and this average GPS position is then stored in the OpenCellID cells database. This average position is then also shown on the OpenCellID map. In case there is only 1 measurement for on GSM base station, this position is indicated to be the position of the cell tower at the same time, which is not necessarily true. The only way to improve the precision of the shown position of a GSM base station is to provide OpenCellID with as many as possible measurements with different GPS positions.
The latitude of the GPS position of a measurement or of a position of a base station.
The longitude of the GPS position of a measurement or of a position of a base station.