A roaming service system for gsm service subscribers in a cdma service area and a location registration method a receipt/sending method and a short message receipt/sending method

The present invention relates to a roaming service system in a CDMA service area for a GSM service subscriber, and a location registration method, an incoming/outgoing method, and a short message incoming/outgoing method in the system. Such a system is wirelessly connected to a CDMA Home Location Register (HLR) that stores subscriber's location information and service information, a CDMA MSC (Mobile Switching Center) connected to the CDMA HLR and in charge of a call connection function, and the CDMA MSC. a CDMA system including a CDMA terminal capable of mounting a SIM card; GSM HLR that stores subscriber's location information and service information, GSM MSC connected to the GSM HLR and responsible for call connection, AuC (Authentication Center) connected to GSM network element and responsible for terminal authentication, the GSM a GSM system comprising a GSM terminal wirelessly connected to the MSC; and an International Roaming Gateway System (IRGS) that is connected between the CDMA system and the GSM system to perform signal conversion so that signals can be exchanged between the systems, wherein a subscriber of the service provided by the GSM system is the CDMA system. If you move to an area where you can use the service provided by the CDMA and install your SIM card in the CDMA terminal, initial location registration for the GSM service subscriber, location registration when changing location, incoming calls with other subscribers, and It enables the sending operation and the short message service operation. According to the present invention, a GSM service subscriber can use his/her SIM card and own number as it is within a CDMA service area. In addition, by performing location registration with the GSM system 200 using a CDMA data burst message, the existing network change is minimized, and a roaming service using the GSM SIM card is possible.