From the documentation for Analytics and Location Engine 1.2.1 (ALE):
Location API
This API retrieves Retrieves historical location objects for a specific MAC client. The last 1000 historical locations
are stored for each MAC address. This API also publishes a location event if ALE receives an RSSI reading from a
single AP for a station....
The API appears to return an X/Y coord pair which is associated with a campus, building or floor map. It also returns an accuracy value for the XY pair.
I dug into this because I was curious if it was getting actual GPS coords but it looks like it's using access point data and floor maps and (now I'm guessing) it may be using multiple RF antennas per AP which lets it separate an area into pie slices. That and signal strength will give you not-too-bad location data.
Yeah, things like location engines aren't for an outdoor citywide deployment, they're really more for trilaterating your position within a controlled area so you can localize someone's device to one corner of the office. It also helps if you have information on the floor plan so you can adjust the signal strength for attenuation from walls -- that's the kind of precision you're looking at.
On a citywide level, though, you don't need that to get an idea of where people have been bringing their phones, just the detection by the access point in question is a major piece of information, readily placing you within a block or so of most APs. Of course, besides the wifi angle, the cell phone companies have something a lot like this too, and sometimes sell it or give it to law enforcement anyway.
Meraki APs have a similar system. The school I work IT for has used it to correctly identify vandals and thieves on several occasions, and recover stolen wireless devices. It's more than possible, it's already put into practice on many large wifi networks.
Location API
This API retrieves Retrieves historical location objects for a specific MAC client. The last 1000 historical locations are stored for each MAC address. This API also publishes a location event if ALE receives an RSSI reading from a single AP for a station....
The API appears to return an X/Y coord pair which is associated with a campus, building or floor map. It also returns an accuracy value for the XY pair.
I dug into this because I was curious if it was getting actual GPS coords but it looks like it's using access point data and floor maps and (now I'm guessing) it may be using multiple RF antennas per AP which lets it separate an area into pie slices. That and signal strength will give you not-too-bad location data.
From:
http://support.arubanetworks.com/Documentation/tabid/77/DMXM...