I haven’t had my gps turned ON for a couple of weeks atleast and still whenever I search for the weather, I get to know the weather of my exact location. None of my devices have their gps activated and yet theyre able to get my location. How is that?
In: Technology
WiFi is a pretty big teller – wireless routers and access points are almost always in a fixed location and don’t move. They also have what’s known as a MAC address, a unique 12 character ID that identifies that piece of hardware.
Phones are capable of recording wireless networks they see (both the name of the network and the MAC address), as well as their GPS coordinates. Companies use this information to build a massive database of wireless networks and their exact location. One such database is WiGLE, which is basically a map of wireless networks. Even if your phone has GPS disabled, if it sees a wireless router or AP with a known MAC address and location, it can determine it’s approximate location.
Cellular signal triangulation is another method – signals from cell towers travel a fixed, well known speed and the towers are also in a fixed position. So your phone can measure the time it takes for a signal to make a “round trip” to the tower (the phone sends a piece of data and waits for a reply), and it’ll be able to figure out how far from the tower it is. If your phone is in range of two towers, then it can figure out the distance to both towers and there’s only two potential spots where those exact distances would overlap. If you’re in range of three or more towers, then there’s only one potential spot where all three signals would overlap with those timings, giving a fairly precise location.
In short, since the location of every cell phone tower and nearly every wireless network is known, your phone can determine its location based on what towers and wireless networks it’s able to see.
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