Post Reply
IMSI [International Mobile Subscriber Identity]

Posts: 29

Joined: 21 Oct 2010 16:17

03 Sep 2012 16:10

IMSI [International Mobile Subscriber Identity]

IMSI [International Mobile Subscriber Identity]

>> IMSI [International Mobile Subscriber Identity] is a unique identification associated with all GSM, UMTS and LTE network mobile phone users

>> It is stored as a 64 bit field in the SIM inside the phone and is sent by the phone to the network. It is also used for acquiring other details of the mobile in the Home location Register (HLR) or as locally copied in the Visitor Location Register

>> To prevent eavesdroppers identifying and tracking the subscriber on the radio interface, the IMSI is sent as rarely as possible and a randomly-generated TMSI [Temporary Mobile Subscriber Identity] is sent instead

>> The IMSI is used in any mobile network that interconnects with other networks. This number is provisioned in the phone directly or in the R-UIM card [Removable User Identity Module] (a CDMA analogue equivalent to a SIM card in GSM)

>> An IMSI is usually presented as a 15 digit long number, but can be shorter

>> For example MTN South Africa’s old IMSIs that are still being used in the market are shown as 14 digits. The first 3 digits are the Mobile Country Code (MCC), and is followed by the Mobile Network Code (MNC), either 2 digits (European standard) or 3 digits (North American standard). The length of the MNC depends on the value of the MCC. The remaining digits are the Mobile Subscription Identification Number (MSIN) within the network's customer base

>> ETERNITY variants, SETU VGB, SETU VGFX variants supports IMSI, the unique identity number of the SIM Card present in the mobile port