The Assisted GNSS Boomed Up Location Based Services

The location based services (LBS) are become increasingly important on telecommunication applications. Many LBS methods have been developed. Mobile station location technologies, including cell-identification (CI), enhanced observed time difference (E-OTD), observed timed difference of arrival (OTDOA), and other third Generation (3G) location technologies, are evaluated in the paper. Above of all, the assisted GNSS (A-GNSS) is analyzed to settle for emergency LBS. The technical advantages to widen AGPS to A-GNSS is developed to focus on the availability and accuracy of LBS. The architecture of software receiver for an integrated GNSS/UMTS is presented to meet the important requirements of seamless indoor/outdoor navigation and communication capability for emergency LBS. The principle platform of an integrated GNSS/GSM/CDMA based on the structure of" Single RF+PC" is implemented. By collecting and processing actual GPS data, the receiver is able to perform PVT calculations with high accuracy and rapid positioning.