Sorry, but it's actually really simple. It's the same reason why on a Jet Blue flight, my phone shows me geolocated to Long Beach, CA for the entire flight (if

Sorry, but it's actually really simple. It's the same reason why on a Jet Blue flight, my phone shows me geolocated to Long Beach, CA for the entire flight (if I don't hold the phone up to the windows). Phones prefer wifi positioning, and that's based on the base station mac addresses. If you are in a highly wifi dense area, moving one AP can auto-propogate its new location by phones reporting in bulk groups of mac addresses they scan at once back to your location provider. ("30 mac addresses detected are know to be in Dublin, but one mac address detected is known to be in New York. Let's update the New York mac address to be Dublin now.") The auto-location-updating is one reason SkyHook wireless died. Once they did the initial scanning, the entire wifi location database can be made reasonably self-updating (and other correlative updates can happen with your drive-every-street-in-the-world mapping vans much less often. Wifi position is more accurate than GPS positioning (plus, faster to locate and less power intensive), so it's always preferred first. GPS positioning is worse (accuracy/power requirements), so GPS tends to be a fallback if you're in a "broad location" category like cell tower only positioning or zero-location positioning (airplanes, mountain tops, etc).