Mobile system and a-gps system with location based service and operating method thereof

A mobile communication location-based system, an A-GPS(Assisted Global Positioning System) location-based system, and an operation method thereof are provided to confirm exact location information at a low cost by flexibly interworking an MS(Mobile Station) based GPS mode and a stand-alone GPS mode, thereby improving the quality of a positioning service. A navigation device(110) demands aiding information to an A-GPS location-based system(140) by driving an MS mode to receive the information, is converted into a stand-alone mode to receive a GPS signal from a GPS artificial satellite(100), and operates location information to apply the operated information. A base station system(120) transmits the aiding information provided from an MSC(Mobile Switching Center)(130). The MSC sets a path by the demand of the navigation device, and delivers the aiding information provided by being demodulated from the A-GPS system. The A-GPS location-based system demodulates the aiding information to provide the demodulated information. The satellite provides the GPS signal capable of operating the location information to the navigation device.