NEXUS S - positioning problem

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I'm a Contributor Level 2 MJBRANDYS
I'm a Contributor Level 2

NEXUS S - positioning problem

I just purchased a NEXUS S,

I am having issues with applications that use positioning such as GOOGLE MAPS.

Everything works fine when I am using GPS.  When  I move out of GPS coverage, 

(this happens when I am my house or a building), the phone uses the mobile network to determine my position.

This is always wrong, it always shows my position very close to the nearest cell tower.

 

For example: when in my house, it shows my position is about 1km from my actual location  (I am on the Vancouver North Shore near Deep Cove and have roamed on to the Rogers network.) . As soon as I step out side, the position is corrected (this does not happen as fast as I would like, as it seems to take some time to re-acquire the GPS data) but then immediately moves to the incorrect position when I step in the house again. 

 

*This also happens at other locations, including North Van Community Centre and Canadian Tire.

 

Any suggestions? Is this a bug with the NEXUS S? or a problem with the FIDO/ROGERS network??

 

 

 

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I'm a Contributor Level 1 WarpedMonkey
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Re: NEXUS S - positioning problem

I don't think it's a problem with either one of those. When you get indoor I'm pretty sure your signal drops quite a bit, and since the GPS is mainly just a triangulation of cell towers, there's a big chance it can't triangulate well enough so it just gives you an approximation of your location.
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I'm a Contributor Level 2 MJBRANDYS
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Re: NEXUS S - positioning problem

Thanks for your reply.

 

I would argue that if this is the case,  then this would be consider this a network problem.

This would mean that the Rogers/FIDO network does not have sufficient coverage in many locations in the North Shore of Vancouver to properly triangulate my position.

 

Also, My wife has an iPhone4 on TELUS that works as expected. I have not have an opportunity yet to switch the SIM cards, and see if the problem is specific to the NEXUS S or the network coverage.  (Stay tuned)

 

 

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I'm an Expert Level 2
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Re: NEXUS S - positioning problem

Fido isn't about to throw up more towers just for location services. Towers are put up for better wireless coverage, period. It isn't a 'problem' with their network, it is a limitation of any triangulation system based on points that are KM's aways from each other.

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I'm an Expert Level 2
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Re: NEXUS S - positioning problem

Also, it is more likely that when you lose GPS, you are falling back to wifi triangulation. This has nothing at all to do with Fido and is completely based on Google's (Skyhook) wifi geo-location database. It can be far more accurate than cell tower locating because of the smaller coverage area of each wifi spot, but can also be less accurate because wifi routers can move or you may not be in range of enough wifi signals.

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I'm a Contributor Level 2 MJBRANDYS
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Re: NEXUS S - positioning problem

I have not been able to do a comparison yet between TELUS and FIDO networks, as the iphone uses a micro SIM that does not fit in the Nexus S. 

 

The software on the Nexus S phone is becoming more suspect. It should be able to take into account that triangulation using data is unavailable, or does not provide enough points to accurately determine the location.  It should realize that I cannot move a 1km in less than a second, and keep the the last GPS determined location. 

 

I did download a nice APP called "antennas" for the Android Market place. It shows the location of the sites being used for triangulation on a map.  There is definitely not enough sites in my area to triangulate my position. It is also smart enough to know when the triangulated position based on insufficient data. 

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I'm a Contributor Level 2 MJBRANDYS
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Re: NEXUS S - positioning problem

Also, 

interesting point regarding wifi and skyhook (thanks 10yearFido).

I turned my Wifi connection off and now Google maps draws a big blue circle around my triangulated position, where the center is now a bit closer to my true location.

 

It seems that the Skyhook database is not as accurate. It would be nice to configure the phone to ignore it, without having  to turn off my wifi. 

(No option in "Location and Security Settings" to individually disable Wifi and Mobile networks, its all or nothing)

 

 

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I'm a Contributor Level 1 whatsurbid
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Re: NEXUS S - positioning problem

You can use Firefly 3.0 on XDA Developers. We put a GPS fix in the ROM few months back. It gives faster location and more accurate.
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