This wiki page provides explanation for some key words often used in conjunction with Cell-ID GAM tracking.
A unique number used to identify the GSM base transceiver station 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.
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.
00 - BT 01 - UK01 02 - O2 Telefonica 03 - Airtel-Vodafone
MCC - Mobile Country Code
This is a unique number for the country with the GSM net the phone is currently connected to.
235 - United Kingdom 262 - Germany 208 - France 214 - Spain