Nokia N900 A-GPS Not Working Anymore - Page 6 - maemo.org

Ulle | # 51 | 2013-08-08, 22:41 | Report

Originally Posted by peterleinchen View Post

Next guess I have is the certificates are not read from cert store, but that Nokia has hard-coded them in the closed binary blob. That would mean we will never get a solution (or someone will disassemble and put new certs or make it read from cert store). Again, just a guess...

Why did it used to work since at least may of 2013 then? I may be wrong stating that it was indeed working, I didn't test for the A of AGPS functionality ...

The reason why I came to this thread was, that I noticed in June that Skype location status wasn't working any more . The satelite icon next to the green Skype status icon was blinking constantly. But when starting Nokia maps app, after some minutes I got a fix and the Skype location was shown and kept updated as long Nokia maps was running. Without Nokia maps the dish icon started blinking again after some minutes. I used supl.google.com since 2011 .

But since I switched to supl.vodafone.com , Skype location status is working again as I was used to (without having to start Nokia maps). So my problem is solved somehow ...

But I got curious about the A for GPS and checked location-test-gui, together with syslogs. I wonder what would be spit out by the logs if AGPS *is working*. I get a lot of satelites in view, but never in use.
Can someone outline a scenario, how to use location-test-gui without any misleading side effects like cached data and so on? Like
- set supl.xxx.com in settings
- shut down
- travel some kilometers (?)
- start up N900
- start location-test-gui, choose AGNSS
- wait 1 (?) min
- If you see your right position then, AGPS is working (?)...
- What shows location-test-gui if it fails (?) ...
- What do the log files look like when OK or failure (?)

I mean some easy steps to do, to get comparable results. Instead of just "I got a fix in my country xyz" or "No it doesnt work here" ...

Thank you.

Side note: Skype location status on N900 might be a questionable feature nowadays, but still the only mobile Skype implementation with that functionality ... thats why I love it.

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eccerr0r | # 52 | 2013-08-09, 00:04 | Report

For those of you who are posting success, please indicate country and your carrier (or ISP if you're using wifi). Reports seem to contradict with each other including my success with lbs.geo.t-mobile.com on T-Mobile USA and others' experiences... This is most troubling in my opinion. This is because if I switch on wifi, AGPS fails. Go back to 3G, it works, like a light switch. (Then again it's super annoying to have to switch networks if I happen to be using wifi at the time.)

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Estel | # 53 | 2013-08-09, 04:45 | Report

Please, stop posting useless and miss-leading "success stories". No one cares if it took 10, 20, or 324574375463 seconds for you to get fix - the one and only *meaningful* of testing AGPS is as per this post, earlier in this thread:
http://talk.maemo.org/showpost.php?p...5&postcount=31

Otherwise, it's just a guesswork. Meanwhile, testing it *properly* isn't hard, at all.

/Estel

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nieldk | # 54 | 2013-08-09, 13:23 | Report

What's the expected outcome from that tool?
Seems like all four tests are responding with a position. Allthough not precise location on my device.
Carrier Telia Denmark
WiFi tried with on/off

Ulle | # 55 | 2013-08-09, 15:50 | Report

Originally Posted by Estel View Post

the one and only *meaningful* of testing AGPS is as per this post, earlier in this thread:
http://talk.maemo.org/showpost.php?p...5&postcount=31

So I tried again location-test-gui tool, right after reboot. Test method AGNSS with supl.vodafone.com
I got 4 satellites within about 20 secs standing next to a window.

Then, after another restart of N900, I tried AGNSS again. Same effect . got 4 satellites after some seconds.

Both locations about 150m away from my real position. But guess what: Before reboot for second test I changed location server to supl.nokia.com (which is known not to work).

So obviously if you got a fix before, just a reboot is not enough for helpful results with location-test-gui and proving if AGPS is reliably working.

Attached Images

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handaxe | # 56 | 2013-08-09, 17:13 | Report

Folks, I believe to test agps you need to use the method acwp after a reboot. That takes the gps receiver out of the equation and relies on the supl server to derive cell based location.

Now, there are many flavours of agps (refer wikipedia) but I believe my n900 was getting cell location while the gps and the supl. server were doing things to get an accurate fix. That cell location has definitely disapeared for me.

Doing a cell loc. first also makes sense as cellphone gps do not store sat. almanacs as do handhelds. Providing that is the job of the supl server and to do that it needs to know broadly where you are. That info saves the need for a sky search for sats and is one of the speedups made by agps

One can also test without location-test-gui by disabling the gps under settings - location but keeping network location enabled. Again a reboot is needed to flush the cache.
Phew - long, sorry.

Last edited by handaxe; 2013-08-09 at 17:16.

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peterleinchen | # 57 | 2013-08-09, 22:29 | Report

So many posts, so many knowledge.
But all "half-knowledge"!

I have to admit I do not know exactly the working of location-test-gui, so I did not post. But for sure is it has different methods and we need the last one. AGNSS (AGPS).
This will give the receiver the desired satellite info like position of current location where are those satellites and their sky posititon (almanach, who says this is not stored on cell phone?).
We may also use the ACWP method, but this will give only ground location based on cell tower info (and/or SIM info, MCC).

For real testing you will need to reset the receiver cache by rebooting. No other chance to reset the GPS chip (afaik).
BUT, this is not enough. Before rebooting you need to reset the stored (not cached) last known position and timestamp.

Code:

gconftool --recursive-unset /system/nokia/location

This is the crudest way, but you will also see the GPS usage disclaimer again?

Happy testing...
And let us know that it will work for you!

For me none of nokia/google/vodafone worked.

P.S.: you may start to try with AGNSS.
I stop after 30/60 sec, that is definitely enough time for AGPS.

If you wanna try the cell tower/provider solution (ACWP), you may see that this method will just fetch the SIM/provider country code and position you in the middle of your currently located country (try it with DISabled SIM and you will see!). If it would fetch supl data it would locate you approximately 150m-1500m off your real position.

Again, happy testing...

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DfLo1913 | # 58 | 2013-08-10, 04:21 | Report

Hey guys which location-test deb file should I install? Thanks

nieldk | # 59 | 2013-08-10, 06:44 | Report

supl.google.com works for me
those with issues, try
test.supl.svc.ovi.com port 7276

pichlo | # 60 | 2013-08-10, 07:15 | Report

How do I set the port?

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