In the mobile communication network, there are usually the following positioning technologies: First, based on Cell ID positioning technology, it is based on the network side to obtain the user's current base station Cell information to obtain the user's current location, the accuracy of which depends on the distribution of mobile base stations and Coverage size; Second, based on the AFLT positioning technology, AFLT (Advanced Forward Link Trilateration) is a unique CDMA technology, in the positioning operation, the mobile phone/terminal simultaneously listens to the pilot information of multiple base stations, the use of chip delay To determine the distance to the nearby base station, the final use of triangulation method to calculate the specific location; Third, based on AGPS (wireless network-assisted GPS positioning technology) positioning technology, AGPS will simplify the work of the terminal, by the network side of the positioning server and terminal cooperation The positioning work is accomplished by shifting the most arduous tasks such as satellite scanning and positioning operations from the terminal side to the positioning server on the network side.
The CDMA positioning technology is a positioning technology developed by Qualcomm Inc. for location-based services and uses the Client/Server method. It combines wirelessly-assisted AGPS and advanced forward-link AFLT triangulation methods to achieve high-accuracy, high-availability, and high-speed positioning. In an environment where both of these positioning technologies cannot be used, the CDMA positioning technology will automatically switch to the Cell ID sector positioning method to ensure the positioning success rate. The wide-area GPS satellite reference network consists of multiple high-sensitivity GPS receivers. It is responsible for monitoring all GPS satellites' ephemeris data, Doppler frequency shifts, and other required positioning information in the coverage area, and dynamically updating the GPS data stored in the positioning platform. Satellite database (corresponding relationship between satellite data and geographical location). When the terminal needs to locate, it notifies the positioning platform of the approximate location (which base station belongs) through the wireless network, and then obtains GPS satellite information through the positioning platform, thereby greatly shortening the satellite acquisition time and greatly reducing the power consumption.
With the help of the powerful computing ability of the positioning server, complex positioning algorithms can be used to reduce the influence of unfavorable factors such as weak reception signals and improve positioning accuracy and sensitivity. The positioning platform sends the latitude and longitude information to the application service platform or returns the terminal to the positioning application through the wireless network.