location accuracy is improved when wifi is turned on.help me?
location accuracy is improved when wifi is turned on.help me?
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I'm assuming that you are talking about using your iPhone with Wi-Fi provides better location accuracy.
If that's the case, it may be important to understand how your iPhone uses GPS for location identification. The iPhone uses GPS satellite data to pinpoint its location. This can take several minutes. However, to reduce this time to within seconds, the iPhone will rely on both cellular and Wi-Fi services to quickly find the location of these GPS satellites. This is called Assisted GPS (AGPS).
A GPS satellite broadcasts a time stamp, its current location, and some limited location information for other satellites every 30 seconds. It can take up 25 of these broadcasts to obtain the entire list of satellite locations. With just 4 of these satellites your iPhone can determine its location within 10 meters. With AGPS, instead of waiting for the live downloads of position data from satellites, any future satellite locations can be estimated. These estimates are downloaded via a network connection in seconds.
Apple uses AGPS for native GPS-lock improvements. Then uses Wi-Fi or cell towers to provide both a fast initial connection and improved GPS accuracy. However, relying on cell towers outside of urban areas are more problematic as tower tend to be farther apart. This is where Wi-Fi "fills" in.
