location via 802.11 networks?

Anyone know of an implementation that would allow location via an 802.11
network? I've found some academic papers, but I can't any existing
software.

Basically the idea is that you set up several wifi APs and then use
signal strength to locate yourself.

Or is anyone aware of a built-in ability for location in any of the
802.11 standards? Something similar to GPS and/or Loran?

We can't use GPS for various reasons so we're looking at alternatives.

--Yan

On Mon, 14 May 2007 09:41:27 -0700, CptDondo rearranged some electrons to
form:

> Anyone know of an implementation that would allow location via an 802.11
> network? I've found some academic papers, but I can't any existing
> software.
>
> Basically the idea is that you set up several wifi APs and then use
> signal strength to locate yourself.
>
> Or is anyone aware of a built-in ability for location in any of the
> 802.11 standards? Something similar to GPS and/or Loran?
>
> We can't use GPS for various reasons so we're looking at alternatives.
>
> --Yan

Cell phone providers that use this try to get the location via
time-of-arrival or angle-of-arrival of the signal from the more than one
base station. Many providers use phones that have a GPS receiver in
them, which gives a very accurate location. All providers in the US are
required by the FCC to provide a location for 911 service within 100m.

Since a WiFi access point is generally not directional, and is
generally not equipped with an accurate time source (ie. GPS receiver),
neither of these are going to work very well.

Using the signal strength as a location source is going to provide a
highly inaccurate location, as the signal strength can very widely
depending on what is between you and the AP (i.e. buildings, trees, etc.)

http://www.pcworld.com/article/id,12...1/article.html


--
David M (dmacchiarolo)
http://home.triad.rr.com/redsled
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