On Sun, 26 Apr 2009 11:34:17 +0100, LR <lrme@privacy.net> wrote:

>> I also created similarly useless results with multiple AP's at my
>> house. If I walked in a circle, the results were similar to the
>> photo. However, if I followed the instructions, and sorta walked in a
>> semi-drunken manner, with lots of cross-over points, the plots looked
>> more like in the examples.

>Is this because you never get close enough to the AP's to get some
>positions with really strong signal levels for each AP?

Dunno. I would have to see the raw collected data to determine what's
happening. Also, I would need some clue as to the algorithm used. In
the outdoor case, my guess(tm) is that the huge variations in signal
strength are rendering the data useless. There may also be a problem
with the large number of SSID's collected. In the indoor case, it
seems to be a problem with the algorithm used, or possibly because the
room is small enough that I might get equal signal strength almost
anywhere in the room. If it does something really crude, like average
or peak detect the indicated signal strength of ALL the AP's heard,
that might explain the almost uniform signal level indicated. It may
also be that my wireless devices are returning garbage values. That's
dubious as I tried 3 different laptops, but still possible. Lots of
possibilities, but nothing definitive, yet.

Unfortunately, the software does not offer any means to filter the
results, limit the test to a specific set of SSID's, or lock it on a
specific channel. It's difficult to tell what's happening without
filters. The full version called "Ekahau Site Survey" does these and
much more.
<http://www.ekahau.com/products/ekahau-site-survey/overview.html>
The problem is that it costs $2,200 and $2,700 for the pro version.
Ouch.

I'll play with it some more later and see if I can deduce how it
works.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558