Mobile Station

     Mobile Station

Subscribers communicate through the wireless network via the mobile station.  There are three types of mobile stations, including:

·        Vehicle mounted

·        Transportable

·        Handheld

Each of these mobiles has a different output power associated with the specific classification.  The common classifications of mobiles and their corresponding output power vary according to type of GSM network.  The mobile class and output power for various GSM network applications are included in following Tables.

 PCS-1900 Mobile Class and Power

Class	Peak Output Power (W)
1	2
2	1
3	.5

 DCS-1800 Mobile Class and Power

Class	Peak Output Power (W)
1	1
2	.25

 GSM-900 Mobile Class and Power

Class	Peak Output Power (W)
1	20
2	8
3	5
4	2
5	.8

Each phone must have a Subscriber Identity Module (SIM).  The SIM is a plastic card with a magnetic strip containing subscriber information that is inserted in the phone.  The information stored on the SIM include:

·        International Mobile Subscriber Identity (IMSI) Number

·        Mobile Station ISDN Number (MSISDN)

·        Personal Identity Number (PIN)

·        Personal Unlocking Key (PUK)

·        Serial number of the SIM

·        Ciphering Key (K_c)

·        Authentication Key (K_i)

·        Temporary Mobile Subscriber Identity (TMSI)

·        SIM service table (indicates which optional services are available)

·        Barred PLMNs

·        Language Preference

·        Additional subscriber related information

Of primary importance are the IMSI and PIN numbers.  Mobile stations cannot access a network, except for emergency calls, without a valid International Mobile Subscriber Identity (IMSI) number.  The IMSI number, stored in the SIM identifies each mobile within a network.

The Personal Identity Number (PIN) is a four to eight digit number that allows a subscriber to lock or unlock his phone to prevent unauthorized use.  If the incorrect PIN is entered three consecutive times the SIM is locked.

As part of the standardization of GSM mobiles there are certain required features including:

·        Display of Called Number

·        Call Progress Indication

·        Country/PLMN Indication

·        Subscription Identity Management

·        Invalid PIN Indicator

·        IMSI

·        Service Indicator

Manufacturers have the opportunity to enhance features in future editions of mobiles as long as the features do not interfere with the network or other mobiles.