Wifi based location

by Skip » Mon, 09 Feb 2009 15:25:31 GMT


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 Does anyone think the wifi based location determination actually
works? I guess I imagine that it would work like this. In the office
where I work, there are a couple of wireless networks. And once I go
inside the building with my phone,the GPS quality goes to crap since
it is indoors--no surprise there. It can literally be off by BLOCKS,
perhaps a half mile or more after I've been inside for a while. I
would like to think that the phone would somehow know that, OK, I
don't have a decent GPS signal, so let's see if I can get a decent
wifi location. Sure, it's not going to tell me what room in the
building I am in, which GPS would be able to do if there wasn't a roof
on the building, but I am OK with that. I just want the locale app to
know what building I am in. So now I have to make circles of about a
half mile in radius (a mile in diameter) to be sure my location in
locale doesn't look like I've left and gone to the default profile,
because now once you go in a building, your accuracy goes down and you
start hopping all over the map.

So, where does the Wifi database live? How can I test it to see how
accurate it is (both in meters and in completeness)? Can I add new
wifi access points to the database? How can I see, for instance, if my
home access point is in the database? What happens if I move and take
my access point with me? How do I update the database?

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Wifi based location

by Skip » Mon, 09 Feb 2009 15:25:33 GMT


 I posted this early this morning and I still haven't seen it, so if it
shows up twice, my apologies.  Feel free to delete this one.

Does anyone think the wifi based location determination actually
works? I guess I imagine that it would work like this. In the office
where I work, there are a couple of wireless networks. And once I go
inside the building with my phone,the GPS quality goes to crap since
it is indoors--no surprise there. It can literally be off by BLOCKS,
perhaps a half mile or more after I've been inside for a while. I
would like to think that the phone would somehow know that, OK, I
don't have a decent GPS signal, so let's see if I can get a decent
wifi location. Sure, it's not going to tell me what room in the
building I am in, which GPS would be able to do if there wasn't a roof
on the building, but I am OK with that. I just want locale to know
what building I am in. So now I have to make circles of about a half
mile in radius (a mile in diameter) to be sure my location in locale
doesn't look like I've left and gone to the default profile since the
GPS accuracy decreases once you go inside a building and it starts
looking like you are hopping all over the place.

So, where does the Wifi database live? How can I test it to see how
accurate it is--both in terms of feet and inches and in terms of
completeness of the database? Can I add new wifi access points to the
database? How can I see, for instance, if my home access point is in
the database? What happens if I move and take my access point with me?
How do I update the database?

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Sponsored Links


Wifi based location

by LB Coder » Tue, 10 Feb 2009 10:58:50 GMT


 The "Use wireless networks" function has nothing at all to do with wifi. It
works using cell tower locations. The wireless provider knows the
coordinates of all its towers, and therefore knows where you are (within a
certain non-impressive degree of accuracy) based on what tower you are
connected to.






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Wifi based location

by Skip » Tue, 10 Feb 2009 19:34:56 GMT


 Yeah, I have come to the conclusion that the phone itself is
misleading, and in fact completely wrong on its setting page, because
when you go to Settings-->Security & location, you can see the setting
for "Use wireless networks" under "My location sources". The secondary
text says "Location determined by wi-fi and/or mobile networks", so it
sure does look like it uses WiFi for positioning. But, alas, I have
determined and agree that the phone does not use wifi for
positioning..... Yet.  I did find this interesting article:
 http://arstechnica.com/hardware/news/2009/01/skyhook-location-sdk-for-android.ars 
indicating that the SkyHook SDK is now available for the android
platform, so hopefully we will see some wifi based positioning apps in
the near future.




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Wifi based location

by Muthu Ramadoss » Tue, 10 Feb 2009 19:42:46 GMT


 oes SkyHook location SDK gives accurate GPS fixes even inside closed
premises like Home, Theater etc.,? I'm interested in hearing about SkyHook
if any Android developers had already used them.

take care,
Muthu Ramadoss.

http://linkedin.com/in/tellibitz +91-9840348914
http://androidrocks.in - Android Consulting.



On Tue, Feb 10, 2009 at 5:04 PM, Skip <skip.morrow.mob...@gmail.com> wrote:


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Wifi based location

by C茅dric Berger » Tue, 10 Feb 2009 20:04:10 GMT


 


AndNav now uses SkyHook, but as far as I know it is not yet really
activated in current releases (still beta).

 http://www.andnav.org/index.php/en/component/content/article/37-about-andnav2/116-skyhook-new-hybrid-positioning-partner 

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Wifi based location

by Muthu Ramadoss » Tue, 10 Feb 2009 20:06:06 GMT


 Thanks Cedric.

Anyone else using SkyHook?

take care,
Muthu Ramadoss.

 http://linkedin.com/in/tellibitz  +91-9840348914
 http://androidrocks.in  - Android Consulting.








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Wifi based location

by Skip » Tue, 10 Feb 2009 22:33:14 GMT


 I sent an email to the Locale developers to see if they were planning
on using it.  I really, really think they need to use it.  Locale, for
the most part, is unusable now because whenever you go in a building,
your gps quality goes way down and the phone no longer thinks you are
in the building.  Great!  *sigh*





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Wifi based location

by Muthu Ramadoss » Tue, 10 Feb 2009 22:40:04 GMT


 If SkyHook works well inside a building, its a welcome addition to Android.
In our current app we need GPS capabilities, and I might as well give
SkyHook a try.

take care,
Muthu Ramadoss.

 http://linkedin.com/in/tellibitz  +91-9840348914
 http://androidrocks.in  - Android Consulting.










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Wifi based location

by Bobby » Wed, 11 Feb 2009 09:31:52 GMT


 the WiFi database is available from multiple sources.  you can
download Navizon www.navizon.com  to your iPhone or WinMobile phone
and recognize you position immediately using wifi and cell tower
triangulation databases.



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Wifi based location

by Wise Old Duck » Wed, 11 Feb 2009 11:04:53 GMT


 Is there a setting that would allow, or a good reason you can't, have
your current location remain at the last "good" known position (ie
right before you went inside)?










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Wifi based location

by Timo Bruck » Wed, 11 Feb 2009 11:04:53 GMT


 Skip... do you have Wi-Fi enabled (under Wireless controls)? You don't
have to be connected to a Wi-Fi network to get the advantages of Wi-Fi-
based positioning, but I believe you do have to have the Wi-Fi driver
running.

You can try a test... turn off GPS location provider. Then see how
good of a fix you get from the Network location provider with Wi-Fi on
and off.

Also, where are you located? Perhaps Google hasn't mapped out your
neighborhood yet.

-Timo

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Wifi based location

by Skip » Wed, 11 Feb 2009 22:26:41 GMT


 Yes, I do have WiFi enabled, GPS disabled (for this test), and my
position shows about 1/4 mile south of where I currently actually am
at.  The big blue circle is about 1/2 mile in radius.  I am in an
office building with a good wireless network, in the center of
Virginia Beach, a pretty good sized metropolitan city.  The position
on the map stays pretty consistent there, but every once in a while,
it will hop up about 3/4 of a mile to the north west.  I think it is
using cell towers for triangulation right now.  What's more, when I
turn GPS back on, the behavior is pretty much the same, so the phone
is recognizing that the cell/WiFi is the better source right now.

It just seems to me that the phone should be able to know that I could
not possibly be 1/2 mile to the south right now because of the fact
that it can see the wireless network in my building right now.  There
is no way the phone could see that nework if I was actually at the
spot where it thinks it is.




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Wifi based location

by Michael Martin - MM Agency » Wed, 11 Feb 2009 23:44:35 GMT


 Isn this actually triangulating your position based on cell towers not the
WiFi signal (when GPS is turned off)?


-----Original Message-----
From: Skip [mailto:skip.morrow.mob...@gmail.com] 
Sent: Wednesday, February 11, 2009 6:26 AM
To: Android Discuss
Subject: [android-discuss] Re: Wifi based location


Yes, I do have WiFi enabled, GPS disabled (for this test), and my
position shows about 1/4 mile south of where I currently actually am
at.  The big blue circle is about 1/2 mile in radius.  I am in an
office building with a good wireless network, in the center of
Virginia Beach, a pretty good sized metropolitan city.  The position
on the map stays pretty consistent there, but every once in a while,
it will hop up about 3/4 of a mile to the north west.  I think it is
using cell towers for triangulation right now.  What's more, when I
turn GPS back on, the behavior is pretty much the same, so the phone
is recognizing that the cell/WiFi is the better source right now.

It just seems to me that the phone should be able to know that I could
not possibly be 1/2 mile to the south right now because of the fact
that it can see the wireless network in my building right now.  There
is no way the phone could see that nework if I was actually at the
spot where it thinks it is.






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Wifi based location

by Skip » Thu, 12 Feb 2009 01:05:00 GMT


 I just took a drive around town with GPS disabled, and I am positive
that all the positioning was coming from cell towers rather than
WiFi.  I have no idea how to get a WiFi fix.  As I drove along the
highway, about every mile my position would hop to my approximate
current position, always with a big blue circle around the position of
about 1/2-3/4 miles in radius.

Since the phone combines the "Cellular and WiFi" positioning in one
setting, I don't know how to test just wifi positioning, but I sure
would like to try it.  To be honest, I don't think the phone does wifi
positioning. Do any of you have evidence to indicate that it does,
other than the label on the setting on the phone itself (which I think
is mislabeled)?
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