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Re: nexus 4 GPS problem? or does google maps not work with gps offline?
someone commented that gps on your mobile phone transmits a signal to a gps satellite to determine your location and thus requires data. this is a wrong understanding of how gps works. HOW GPS works: there are many GPS satellites in the sky at any given moment (usually a minimum of 4 is required to determine your location. more satellites reduces the degrees of freedom in the estimate of your location, thus reducing spatial errors associated with the locating the receiver (e.g. cell phone)). these GPS satellites are constantly broadcasting their "in orbit" location at a time code. your GPS receiver (e.g. cell phone OR hand held garmin, etc) DOES NOT transmit to the GPS satellite at all. your GPS receiver "sees" all the signals from the GPS satellites and using the encoded location and associated small time differences between the various satellites, via their signals, is able to determine your location on a map that is located on your handheld device. NEVER does your device transmit to gps satellites. it does not have the hardware to do this even if it wanted to try.
the reason your cell phone gps needs data is due to continually downloading map information. there is some alternative methods for the phone to also incorporate cell towers in the location estimate, but this is not necessary. the stock google maps program on the nexus phone is programmed not to have functioning gps when no data is available. im sure there is some app that fixes this problem, as only having the maps locally stored is required for the user to reference their GPS derived location to other geographic features (e.g. a map)