Location Area Identity (LAI)
LAI is used for location updating of mobile subscribers.
LAI = MCC + MNC + LAC
MCC = Mobile Country Code (3 digits), identifies the country. It follows the same numbering plan as MCC in IMSI.
MNC = Mobile Network Code (2 digits), identifies the GSM/PLMN in that country and follows the same numbering plan as the MNC in IMSI.
LAC = Location Area Code, identifies a location area within a GSM PLMN network. The maximum length of LAC is 16 bits, enabling 65 536 different location areas to be defined in one GSM PLMN.