We know that the GPS receiver works with three or more satellite communication, and confirm the distance, the receiver goals is calculated by the three-dimensional coordinates. However, the actual positioning accuracy is related with the number of satellites receiving, satellite azimuth, signal strength and other related.


In addition, GPS performance has a time to first fix (TTFF), this parameter depends largely on the sensitivity of the receiver and satellites status. Under the same equipment conditions, the receiver performance in the open area is much better than in high-rises in downtown. it can be said that it is a  unfavorable environment among the buildings, in such weak signal status, the GPS tracker may take several minutes to analyze and calculate signal.


A-GPS technology came into being, it’s full name (Assisted GPS).

A-GPS is mandated by the US Federal Communications Commission (FCC) to provide positioning of cellular phone driven emergency callers on E911 project. A-GPS is intended or improve TTFF, or make the positioning operation TTFF become possible when it does not improve


When a GPS signal is not reliable, A-GPS devices can be obtained additional information through the mobile network infrastructure time synchronization, Doppler, frequency, etc., and get the location of the mobile device by three times a few measurements. By communicating with a plurality of base stations, calculate position can be implemented in a mobile device or network server. This provides a more reliable way to obtain location information.


Construction based on user-level A-GPS does not need to add control plane mobile network special hardware, and this method is universal for different mobile standards. So long as a dedicated A-GPS chip can be achieved at low cost A-GPS positioning


Unfortunately, the A-GPS positioning network transmission must be achieved through multiple (up to six one-way transmission), which is undoubtedly require a great deal of resources for operators. Under China’s current 2G network air resources scarce, it is unrealistic to carry out A-GPS. Thus, 3G is the promotion of good soil for A-GPS.

17Jun 2016
GPS locator for fleet management

Currently there are many brands of GPS locators on the market, depending on the performance of the product have different price, ranging from several hundred to several thousand. GPS locator can be divided into personal and vehicle terminal positioning tracker. GPS car terminal is installed in the vehicle includes a GPS receiver capable devices. GPS […]

14Jun 2016
car gps tracking system

For the entire GPS tracking system, in fact, ground control part is the core of the whole system. All GPS satellites broadcast ephemeris for navigation and positioning, it is provided by the five monitoring stations located in the ground. Ground system is responsible for monitoring GPS signal, data collection, calculation, navigation injection messages, status diagnosis, […]

09Jun 2016
car gps network

June 11, Beijing National Convention Center, The 2014 geographic information Developers Conference (WGDC2014) kicked off here as the theme of “open intelligence fusion”. Geographic Information Development Conference held since 2012, during these three years, with the rapid development of China’s geographic information industry, now has become the most influential in the field of geographic information […]

06Jun 2016

Positioning and monitoring in real-time – Clean Street without trash   According to the news reports, Beijing launched integrated management mode which implement of urban and rural, regardless of the area Street station, regardless of primary and secondary roads, regardless of the community, the implementation is just for a standard. Equip with full-time cleaners, advanced […]

04Jun 2016
motorcycle gps protection

Use of GPS positioning function to get back motorcycle which has been sold, 21-year-old employee of the property sell the same motorcycle four times in 2 months. Court of Final Appeal has recently sentenced him to 10 months.   According to Beijing News agency reported the news article:   The prosecution alleges that, in September […]

03Jun 2016
gps tracker for big truck

In related news: From July 1, “Road transport vehicle dynamic supervision and management approach” (the “Approach”) will be formally implemented; there would be higher requirements and constraints on dynamic regulation of road transport vehicles   “Rules”, the road transport vehicles, including tour buses, charter buses, three or more classes lines bus, dangerous goods transport vehicles, […]