Basic Overview of GSM 2G Network

Basic Overview of GSM 2G Network PLMN Correct Answer: public land mobile network; entire area of service offered by provider NSS Correct Answer: network switching subsytem; contains MSC, VLR, HLR, AuC, EIR, GMSC MSC Correct Answer: mobile switching center; brains of GSM network, controls 5-10 BSC's VLR Correct Answer: visitor location register; temporary database for subscriber data, all information is stored here as long as MS is in range of the VLR HLR Correct Answer: home location register; permanent database for subscriber data AuC Correct Answer: authentication center; provides security so that a third party cant access subscriber's network services. The AuC will contain the same Ki as the SIM card, these two have to match up. The Ki is paired with a RAND (randomly selected encrypted number) and the IMSI of the MS. All of this authentication process is done under an A3 encryption algorithm. EIR Correct Answer: equipment identity registry; validate IMEI of MS GMSC Correct Answer: gateway mobile switching center; used to connect subscribers to outside networks BSS Correct Answer: base station subsystem; contains BSC and BTS BSC Correct Answer: base station controller; controls up to several hundred Base Stations BTS Correct Answer: base transceiver station; max range 35 km Cell Correct Answer: area covered by a BTS IMSI Correct Answer: international mobile subscriber identity; three part 15 digit number that identifies the subscriber to the GSM network. MCC Correct Answer: mobile country code; part one of the IMSI, 3 digits, identifies country of domicile of the subscriber. Combined with the MNC this makes up the PLMN MNC Correct Answer: mobile network code; part two of the IMSI, 2 digits, identifies home GSM network of the subscriber. Combined with the MCC this makes up the PLMN MSIN Correct Answer: mobile subscriber identification number; part three of the IMSI, 9 digits, number assigned to the SIM card by service provider SIM Correct Answer: subscriber identity module; contains all processes involving the authentication key. Also contains the IMSI and all mobile subscriber related information. (MSISDN, last known LAC, phone book, authentication and encryption keys...) TMSI Correct Answer: temporary mobile subscriber identity; will be assigned when outside of your HLR IMEI Correct Answer: International mobile station equipment identity; used by GSM network to verify the equipment being used and whether or not to accept calls made by it. 15 digits, can be found under the battery or by dialing *#06# TAC Correct Answer: type allocation code; 8 digit code that identifies the ME down to the make and model MSISDN Correct Answer: mobile station integrated services digital network number; the permanent dialed phone number. three part 10-12 digit number. CC Correct Answer: country code; part one of the MSISDN, 1-3 digits NDC Correct Answer: national destination code; part two of the MSISDN, 3 digits SN Correct Answer: subscriber number; part three of the MSISDN MSRN Correct Answer: mobile station roaming number; temporary number used to route calls directed to a mobile station. BSIC Correct Answer: base station identity code; broadcasts information to identify a BTS. Consists of a Network Color Code and a Base Station Color Code NCC Correct Answer: network color code; part one of the BSIC, used to differentiate between OPERATORS using the same frequencies BCC Correct Answer: base station color code; part two of the BSIC, used to differentiate between CELLS utilizing the same frequencies CI Correct Answer: cell identity; up to 5 digits that identify a cell within a BSS. Combined with the LAI it makes up the CGI CGI Correct Answer: cell global identification; joining of