lardman | # 31 | 2010-08-23, 09:08 | Report

From reading the thread there's some confusion about what the SUPL server actually does, and how the other location levels are implemented. SUPL doesn't all of a sudden make your lock more accurate, it simply improves the time it takes for the GPS chipset to achieve a lock. Now in our case, the performance of the GPS without assistance data is miserable, which might be why people are confused about AGPS. Anyway, for reference, and to explain why some people have poor accuracy (caused by a lack of SUPL data imho):

There are 4 levels of accuracy you can ask for from the location framework. These are:

LOCATION_METHOD_CWP
LOCATION_METHOD_ACWP
LOCATION_METHOD_GNSS
LOCATION_METHOD_AGNSS

Their description in rough terms:

The first, Complimentary Wireless Position, uses data provided to the phone by the GSM protocol so that it knows which country the cell/service provider lives in. This method does not require any data transfer (over and above the low level GSM stuff that makes your phone work at all).

ACWP (Assisted Complimentary Wireless Position) lets your phone query the base station it's connected to and has it return a location. This requires a small amount of data transfer.

GNSS (Global Navigation Satellite System) uses the GPS to obtain a fix. In this mode AGPS is not used, and therefore no data transfer is required, but it will probably take an age and you will need a clear view of the sky.

AGNSS (Assisted Global Navigation Satellite System) in this mode AGPS is used (i.e. the SUPL server is queried for ephemeris and almanac data for the current location as provided by the ACWP method, these data are then used to prime the GPS chipset so it gets a lock quicker).


So, from what we see here, the Google SUPL server is no longer providing us with information for whatever reason, so the location framework will fall back to using the GPS with no assistance (which means it make take some number of aeons to get a fix), and in the meantime you are just seeing your location as provided by the local cell towers (i.e. ACWP)

jessi3k3 | # 32 | 2010-08-23, 09:33 | Report

Not even that. using Google's supl server It always sends me to 39.0000 0.0000 (Somewhere off the coast of Spain in the Mediterranean Sea) and proceeds to take forever to find my gps coordinate.

I'm in California, US

manavs | # 33 | 2010-08-23, 09:48 | Report

I was using the google server but switching to supl.nokia.com fixed it. It establishes a fix in seconds now.

lardman | # 34 | 2010-08-23, 19:05 | Report

Well yeah, if Google are no longer accepting requests from arbitrary devices, and it's sending the wrong ephemeris data to the chipset, then it will indeed take an age to find a lock.

I'm interested in your saying that you are sent to [39,0], how do you see this? If Google is just sending the wrong ephemeris data I'd expect the GPS to just take ages to lock, and the other location methods to be used in the meantime... Unless the SUPL server is also used for cell location (which I didn't think it was).

ABerri | # 35 | 2010-08-24, 04:46 | Report

Wow I'm so glad I found this thread. I was already on supl.nokia.com and my GPS was locking me about 1/4 of a mile away from my actual point.

So I thought about switching it to the google one but apparently that's what everyone was on and you are all saying it doesn't work anymore.

I'm hoping we can have a fix soon. I'll keep track of this thread for the next few weeks.

lardman | # 36 | 2010-08-24, 11:12 | Report

The question is then whether you have a true GPS lock (if so, it sounds like whatever maps you are using are wrong as 1/4 mile is rather a large inaccuracy) or simply a cell tower location.

ABerri | # 37 | 2010-08-24, 20:43 | Report

That's the thing, I don't have a true GPS lock. Evans Rd is about 1/4 of a mile away from my exact location. I'm using the regular Ovi Maps that's already pre-installed and I have the latest update of Maemo that came out in May of this year.

No biggie, I guess I'll just wait for supl.google.com to be back up and running.

bocaJ | # 38 | 2010-08-24, 21:21 | Report

I'll just share a story:

I was convinced that my GPS was broken, because I could only get an AGPS accuracy level fix, and whenever I started GPSJinni or other location aware programs, the little satelite dish icon would appear, stop blinking like it had gotten a lock, but would only tell me my location to an accuracy of about half a mile.

Finally, I went into settings -> location and saw that the "enable" checkbox for GPS was blank. I think I had disabled GPS once, but it didn't turn back on automatically. Hope this might help some of you.

ed00 | # 39 | 2010-08-25, 01:34 | Report

Overwriting %gconf.xml file made GPS lock in less than 5 second. Tested it today many times in a different locations with Data/WiFi -- on/off getting same result. Sounds weird but thats how its never was so fast. Even posting now i turned it on to see if it still works and got locked in about 8 second ( indoor )

By founding where GPS kept its catch and just backup %gconf.xml file then remove and install it back did the trick.

Code:

/etc/osso-af-init/gconf-dir/system/nokia/location/lastknown/%gconf.xml

location server on supl.nokia.com
phone is OC @ 1000mhz

lardman | # 40 | 2010-08-25, 07:57 | Report

As an interesting aside, Ovi maps does not indicate the position uncertainty (e.g. by drawing a big red circle around the position dot). I wonder if this has led some people to think that they have a GPS lock when in fact they don't.

Certainly this is very poor from a usability standpoint as you have no idea whether you are actually where it says you are! I raised a bug about it earlier in the year (iirc the time).