SIMSIM• The SIM is a removable card that plugs into the ME.• It identifies the mobile subscriber and provides information about the

service that the subscriber should receive.• The SIM contains several pieces of information

– International Mobile Subscribers Identity ( IMSI ) - This number identifies the mobile subscriber. It is only transmitted over the air during initialising.

– Temporary Mobile Subscriber Identity ( TMSI ) - This number also identifies the subscriber. It can be alternatively used by the system. It is periodically changed by the system to protect the subscriber from being identified by someone attempting to monitor the radio interface.

– Location Area Identity ( LAI ) - Identifies the current location of the subscriber.

– Subscribers Authentication Key ( Ki ) - This is used to authenticate the SIM card.

– Mobile Station International Standard Data Number ( MSISDN ) - This is the telephone number of the mobile.

NETWORK COMPONENTSNETWORK COMPONENTS

SIMSIM• Most of the data contained within the SIM is protected against reading

(eg Ki ) or alterations after the SIM is issued.• Some of the parameters ( eg. LAI ) will be continously updated to

reflect the current location of the subscriber.• The SIM card can be protected by use of Personal Identity Number

( PIN ) password.• The SIM is capable of storing additional information such as

accumulated call charges.

G S M

FULL SIZE SIM CARD MINI SIM CARD

NETWORK COMPONENTSNETWORK COMPONENTS

98 XXX 12345

CCNDCSN

CC NDC SN

= Country code= National Destination Code= Subscriber Number

Mobile Station International Subscribers Dialling NumberMobile Station International Subscribers Dialling Number ( MSISDN ) :( MSISDN ) :• Human identity used to call a MS• The Mobile Subscriber ISDN (MSISDN) number is the telephone

number of the MS.• This is the number a calling party dials to reach the subscriber.• It is used by the land network to route calls toward the MSC.

NETWORK COMPONENTSNETWORK COMPONENTS

Equipment Identity Register ( EIR )Equipment Identity Register ( EIR )

White List

All Valid assigned ID’s

Range 1Range 2

Range n

Black List

Service denied

MS IMEI 1MS IMEI 2

MS IMEI n

Grey List

Service allowedbut noted

MS IMEI 1MS IMEI 2

MS IMEI n

EIR

NETWORK COMPONENTSNETWORK COMPONENTS

TAC FAC SNR

6 2 6 1

TACFACSNRSP

SP

= Type Approval Code= Final Assembly Code= Serial Number= Spare

International Mobile Equipment Identity ( IMEI ) :International Mobile Equipment Identity ( IMEI ) :• IMEI is a serial number unique to each mobile• Each MS is identified by an International Mobile station Equipment

Identity (IMEI) number which is permanently stored in the Mobile Equipment.

• On request, the MS sends this number over the signalling channel to the MSC.

• The IMEI can be used to identify MSs that are reported stolen or operating incorrectly.

NETWORK COMPONENTSNETWORK COMPONENTS

HOME LOCATION REGISTER( HLR )HOME LOCATION REGISTER( HLR )• The HLR contains the master database of all subscribers in the PLMN.• This data is remotely accessed by the MSC´´s and VLRs in the network.

The data can also be accessed by an MSC or a VLR in a different PLMN to allow inter-system and inter-country roaming.

• A PLMN may contain more than one HLR, in which case each HLR contains a portion of the total subscriber database. There is only one database record per subscriber.

• The subscribers data may be accessed by the IMSI or the MSISDN.• The parameters stored in HLR are

– Subscribers ID (IMSI and MSISDN )– Current subscriber VLR.– Supplementary services subscribed to.– Supplementary services information (eg. Current forwarding

address ).– Authentication key and AUC functionality.– TMSI and MSRN

NETWORK COMPONENTSNETWORK COMPONENTS