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As I understood it (correct me if mistaken); Wifi Positioning System has a network of routers of some sort, and when I plug in my new device, by using existing devices whose locations are known, they can locate my new router.

I have few questions about this;

  • How do they collect my info? Do they ask for permission? Can they use my device for determining the location of other devices? Does my router/device send any data about location or do they only use my signal power?

  • Secondly, if my router works in an intranet, without Internet connection, can they still locate my router? If not, can I some how use my router for GPS purposses without having any GPS devices?

This may seem of topic but, my questions are security related in a way... I want to use location services locally without an Internet connection and hopefully without sending data to other devices.

Xander
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cengizUzun
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2 Answers2

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So several companies have a database of Wireless Access Points (Google, Apple, Skyhook).

In terms of how the data is collected, I don't believe that any of the companies have made official statements on the matter, but there's a couple of likely avenues.

First one point is that your wireless Access Point broadcasts it's BSSID address into, likely public, areas like the street outside your door. It's fundamentally legal (AFAIK) for someone to pick up wireless signals in a public area. So it's not your location that's been directly gathered, it's the location of a device in a public area together with the signal strength and BSSID address of your Access point

  • War-Driving. Google in particular is known to have used this technique, when they equipped their street view cars with wi-fi detection capabilities. This would allow them to assemble a large database.

  • Mobile Devices. Both Google and Apple (and other mobile device manufacturers) have huge numbers of mobile devices with GPS and Wi-Fi. If those devices report back Access Points that they have seen in a specific location, then it would be easy for those companies to assemble this information into a database.

In terms of your devices Internet connection, it doesn't really matter as it's not your device that is sending them information, it's other devices that "see" your device in passing.

Rory McCune
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  • so what happens when i use location service when connected to my router is, my request is send to DB, my router info gets checked to see if it is on their tables, than my location is set? – cengizUzun Feb 25 '14 at 09:59
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The Wifi Positioning System tells where you are by seeing what wireless access points are visible, looking up their assumed locations in a database, and calculating the most likely position for the WPS antenna.

In theory, WPS doesn't require an Internet connection to tell where you are. If the device comes pre-loaded with a database of AP locations, it can do the lookups and calculations internally, without ever going out on the Internet.

In practice, it does. I've been playing around with my own implementation, and my database takes up 14MB to cover only a few square miles (and that, with only moderate density). A complete database would take more storage space than any router I know of has, and would almost immediately be out of date.

Mark
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