Roaming service system for GSM service subscriber in CDMA service area, and method for registering locations and transmitting and receiving signals and short messages using the system

The present invention relates to a roaming service system in a CDMA service area for a GSM service subscriber, a location registration method in the system, and a call/receive method. The roaming system of the present invention is connected to the GSM system and performs roaming services in a CDMA service area for GSM service subscribers. The roaming system is connected to a CDMA network and a CDMA terminal equipped with a SIM card used in a CDMA HLR and GSM service area that stores subscriber location information and service information is wirelessly connected and performs a call connection function to the CDMA terminal. CDMA systems including CDMA MSC; and an international roaming gateway system that is connected between the CDMA system and the GSM system to convert signals so that signals can be exchanged between the systems, and performs service authentication of the CDMA terminal equipped with the SIM card in conjunction with the GSM system. includes According to the present invention, a GSM service subscriber can use his/her SIM card and his/her own number as it is within a CDMA service area.