1. Field of the Invention
The present invention relates generally to a mobile communication system, and in particular, to a system and method for allowing a GSM subscriber to use a SIM card even in a CDMA service area.
2. Description of the Related Art
Unlike a code division multiple access (CDMA) terminal, a GSM (Global System for Mobile communication) terminal has a subscriber identity module (SIM) card mounted in it. The SIM card, which is a smart card detachable from the terminal, includes therein a microprocessor and a memory chip for storing various information of the user. The SIM card is divided into an IC (Integrated Circuit) card type and a plug-in type. On the SIM card are stored subscriber information and information loaded in a pre-personalization state. The subscriber information may include:
Serial Number
Service Code
Block/Unblocking Status
(Pre-)Personalization Data
Authentication Algorithm Parameter
Authentication Key
Encryption Algorithm
IMSI (International Mobile Subscriber Identity)
(Pre-)Personalization and Re-personalization Key
Cipher Key
Cipher Sequence Number
TESI (Temporary Mobile Subscriber Identity)
LAI (Location Area Identity)
Location Update Time
Update State
Forbidden PLMN (Public Land Mobile Network) List
Access Control Class
PIN (Personal Identification Number)
PIN Error Count
PUK (Personal Unblocking Key)
Abbreviated Dialing
Barring Outgoing Calls
Further, the IMSI includes an MCC (Mobile Country Code), an MNC (Mobile Network Code) and an MSIN (Mobile Subscriber Identification Number).
A GSM terminal (or GSM phone), using the SIM card, operates in a communication method different from that of a CDMA terminal (or CDMA phone). Therefore, users of the GSM terminal cannot use their own SIM card when traveling to a CDMA service area. In this case, the user conventionally leases a CDMA terminal (phone) from a service provider and this inconveniences the user with an additional charge. Furthermore, the user cannot use various additional services registered in the SIM card, such as an abbreviated dialing function. Therefore, there has been a demand for a method capable of allowing the GSM subscriber to use his SIM card even in a CDMA service area.
It is, therefore, an object of the present invention to provide a system and method for allowing GSM subscribers to use their SIM card even in a CDMA service area.
It is another object of the present invention to provide a CDMA terminal (phone) mounted with a SIM card for use in a non-GSM service area, and a method for controlling the same.
To achieve the above objects, there is provided a system for allowing a GSM subscriber to use a SIM card in a CDMA service area. In the system, a CDMA terminal having a mountable SIM card, includes a SIM interface for interfacing between the SIM card and a controller of the CDMA terminal. The CDMA terminal reads unique subscriber information for SIM card verification from the SIM card and sends thee unique subscriber information, when the SIM card is mounted therein, and enables the SIM card upon receipt of verification for the SIM card. A CDMA subsystem sends a verification confirm request for the SIM card to a GSM subsystem using the unique subscriber information and information about a predetermined agreement with a GSM system upon receipt of the unique subscriber information for SIM card verification; and assigns a unique virtual management number for the CDMA terminal mounted with the SIM card and sends SIM card verification to the CDMA terminal when the GSM subsystem verifies the SIM card. The GSM subsystem verifies the SIM card in response to the verification confirm request for the SIM card and sends the verification result to the CDMA subsystem. A public network connects the CDMA subsystem and the GSM subsystem.