Kismet Wireless

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Posted by:dragorn
Subject:Assigning location to AP
Date:22:42:58 03/12/2009

> How does Kismet/GISKismet assign the GPS coordinates of an access point? Does it use both the GPS data (from external GPS device) and/or the signal strength at each point during a survey to estimate the location? Or does it only use the GPS data from the external GPS device that is used?

Signal strength is not in general usable.

Many cards don't report valid signal strength at all.

Many more report completely bogus data in monitor mode.

Even knowing the signal strength, you don't know the transmitter power, antenna, or line of sight.

The only data which is trustworthy is "was there a packet" and "where were we when we saw it".

You can make some rough assumptions about transmitter power, but it's not trustworthy. Enterprise gear dynamically scales power, point to point gear can show huge EIRP differences if you're in the path, busses, trees, people, concrete all present major signal degradation issues as well.

I'd love there to be a way to get better data, but I haven't been able to think of something that doesn't introduce as much or more guesswork than actual data yet.

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