...zur Erhellung, hier ein wenig Spekulatius 
Auszug aus "GPS Compendium - Essentials of Satellite Navigation -" Seite 119
Von u-Blox, hier zu finden.
7.7.2
Principle of A-GPS
A rapid determination of position and measurement during periods of weak signals can be obtained by providing additional satellite orbit data and other GPS information. This information is made available through other communications channels, for example via GSM, GPRS, CDMA or UMTS. This application is known as Aiding and is used in Assisted-GPS (A-GPS, or AGPS). A-GPS is a function or service that uses Aiding-Data in order to speed up the determination of position. The GPS receiver obtains Aiding-Data via a mobile communications network or directly over the Internet. The Aiding-Data includes information over such things as:
- Satellite constellation (Almanac)
- Precise orbital data (Ephemeris, orbits)
- Time information
- Doppler frequency and frequency-offset (error) of the GPS receiver
With the availability of this Aiding-Data the GPS receiver can very quickly determine position, even under poor signal conditions. With weak signals this is often the only way to get a position fix. Depending on the complexity and completeness of the Aiding-Data the reduction of the start-up time can be significant. The start-up time remains dependent on the strength of the GPS-Signal. It is generally true that the higher the availability and the accuracy of aiding information, the faster is the start-up time.
Ende Auszug.
Da steht noch deutlich mehr drin, etwa auch, wie die Firmware des GPS-receivers aus der Laufzeit der Signale den Standort errechnet.
Die Angaben dort sind möglicherweise verlässlicher als das, was von Google kommt.
Gruß
Wolfgang
