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GSM IDENTIFIERSIMEI - International Mobile Equipment IdentityIts an internationally-unique serial number allocated to Mobile Station (MS) hardwareat the time of manufacture. It is registered by the network operator & stored inunthetication !enter (u!) for "alidation purpose. #his number consists of type

appro$al code% final assembly !odeand serial number of the mobile station. #henetwork stores the IMI numbers in the quipment Identity 'egister (I').

IMSI - International Mobile Subscriber Numberhen a subscriber registered with a network operator% a unique subscriber IMSIidentifier is issued & stored in the SIM (Subscriber Identity Module) of the MS. MScan only functional fully% if it is operated with a $alid SIM inserted into a MS with a$alid IMI.#he total length of the IMSI is * digits and it consists of the following elements+

M!! , Mobile !ountry !ode (three digits)M! , Mobile etwork !ode (two digits)MSI , Mobile Subscriber Identification umber (ten digits)TMSI - Temporary Mobile Subscriber IdentityIts used to protect the true identity (IMSI) of a subscriber. It is issued by & storedwithin a "' (not in the /') when an IMSI attach takes place or a ocationrea() updates takes place. #he issues #MSI only has $alidity within a specific . #he#MSI is used for security purposes% so that the IMSI of a subscriber does not ha$e to betransmitted o$er the air interface. Its a temporary identity% which regularly getschanged.

MSISDN - Mobile Subscriber International ISDN numberIt represents the #rue or dailed number associatedwith the subscriber. It is assignedto the subscriber by the network operator at registration & is stored in SIM. Itspossible for a MS to hold multiple MSIS0s% each associated with different ser$ices. Itcontains the following elements%

!!, !ountry code (11,2rance% 1*3,2inland% etc.)0!, ational 0estination !odeS, Subscriber umber

MSRN - Mobile Subscriber Roaming NumberIt is temporary% location-dependent IS0 number issued by the parent "' to all MSs

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within its area of responsibility. It is stored in "' & associated /' but not in the MS.#he MS' is used by "' associated MS! for call routing within MS!4"' ser$ice area.

!! , !ountry !ode (of the $isited country)0! , ational 0estination !ode (of the ser$ing network)S , Subscriber umber

LI - Location rea Identityach location area within 5M (5ublic andline Mobile etwork) has an associatedIntenationally unique identifier (I). #he I is broadcasted regularly by the 6#Ss onthe 6roadcast !ontrol !hannel(6!!/)% thus uniquely identify each cell within anassociated location area (). It structure is as follows%

M!!, Mobile !ountry !ode (of the $isited country)M!, Mobile etwork !ode (of the ser$ing 5M)!, ocation rea !ode

!I - !ell Identi"ierIts an identifier assigned to each cell within a network. howe$er% !I is onlyunique within a specific . hen combined with the internationally unique I for itsassociated % the 7lobal !ell Identity (7!I) is produced which is alsointernationally unique.

#SI! - #ase Station Identity !odeach 6#S is issued with a unique identity% the 6SI! & is used to distinguishneighbouring 6#Ss. It is neededto identify that the frequency strength beingmeasured by the mobile station is coming from a particular base station.

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