GPS is stuck with a set of satellites - how to remove them from memory?

[Compusmurf]

Originally Posted by jethro_static

WAAS is not a satelite. LMFAO. It's a server developed by garmin for a more acurate position. 3 feet range as oppose to non WAAS enabled GPS chips, The range can be up to 3 meters.

Incorrect.

WAAS, Wide Area Augmentation System is NOT a server developed by garmin. It's owned by the US Govt, DOT and FAA for precision flight approaches. Its designed to correct signal errors and it uses ground stations AND satellites.

http://www8.garmin.com/aboutGPS/waas.html

[ckl_88]

Originally Posted by tichi

I seem to know why SOMETIMES it takes forever
to get a satellite lock with GPS.
(I learn that many users experience this problem, including those on Bell, and including those with NSFSAN's ROM 1.10, like me).

After you get a successful lock, a few satellite numbers (like those 4,2,9,12,22 etc, that you see in GPSViewer) are stored
somewhere on the phone.

Next, when after some time (overnight, let's say), you try to get another lock, the OLD satellites moved, they are not available anymore,
but the phone tries to use them anyway, WITHOUT UPDATING...

(my highly subjective perception after some observations is that if there's is one-two OLD satellites still avaialble, it may be still OK for the phone to find the new ones, but if NONE of the old satellites are available,
the phone is stuck, and may sit forever looking for them..

what helps is a SOFT-RESET (which clears some memory, I suppose) - after that - ther's a A FAST (10ns) LOCK, with NEW SET OF SATELLITES (e.g .13. 15. 3. 7 etc )..

so my question is WHERE those satellite are stored, and how to clean them without doing a soft-reset?

("HTC GPS Tool" that has some "clear-memory" button does not seems to help, maybe because it is for another phone model?)

EXPERTS, PLEAAASE!

hmmm... didn't you say in another thread that you were getting 10sec locks (cold fix)?

Anyway, have you tried turning off the EnableGPSSmartMode in the SUPL AGPS registry? here is link to the post I'm looking at:

http://forum.ppcgeeks.com/showpost.p...09&postcount=8

[tichi]

Originally Posted by ckl_88

hmmm... didn't you say in another thread that you were getting 10sec locks (cold fix)?

Anyway, have you tried turning off the EnableGPSSmartMode in the SUPL AGPS registry? here is link to the post I'm looking at:

http://forum.ppcgeeks.com/showpost.p...09&postcount=8

yes, IF NOT STUCK - within TENS of seconds (from 5 seconds up to a minute maybe).. sometimes can go slower, though, even if not stuck..

thank you for the link, I'm reading right now something about AGPS, and
I see that your link is something about AGPS too..

BTW, here are my AGPS settings,

[HKEY_LOCAL_MACHINE\Software\HTC\SUPL AGPS]
"EnableAGPS"=dword:00000001
"EnableGPSSmartMode"=dword:00000001
"GPSMode"=dword:00000002
"NumberFixes"=dword:3b9ac9ff
"QoSAccuracy"=dword:00000032
"QosPerformance"=dword:00000059
"ServerIP"="195.207.101.126"
"ServerPort"=dword:00001e6c
"TimeBetweenFixes"=dword:00000001

_________________________
I wonder if all this is of any help for BEll users, for example, how
a server located somewhere in Belgium can know about Bell.ca cell towers?

also also I wonder if anyone could share their AGPS settings to compare?

[tichi]

Originally Posted by ckl_88

http://forum.ppcgeeks.com/showpost.p...09&postcount=8

cool!, thank a lot again, this post tells many useful things
(I'll allow myself to quote it here too):

Originally Posted by hetaldp

Being we are non Sprint User the Assistance Server will never accept Requiest from Outer Network so we must have to put the GPS into Autonomous Mode (Self Fixing)

I am using this Setting in SULP (Secure User Plane Client With Extended Ephemeris)

[HKEY_LOCAL_MACHINE\Software\HTC\SUPL AGPS]
"GPSMode"=dword:00000001
"EnableGPSSmartMode"=dword:00000000
"EnableAGPS"=dword:00000000

GPSMode = 1 means Autonomous (Self Fix no Assistance Required, Pessimistic Approach, Very Slow but Very Accurate)
GPSMode = 2 means Assisted by Server (Less Optimistic, Somewhat Slow but Medium Accuracy Quality)
GPSMode = 4 means Assisted by Server with Extended Ephemeris (Very Optimistic, But Sometime we loose Accuracy Quality)

EnableAGPS = 1 Means Enabled AGPS and 0 Disables it

EnableGPSSmartMode = 1 Save Downloaded Ephemeris Data and also Send it Assitance Server to Update / Fine Tune Extended Ephemeris Data on Server (Require Internet Connection), 0 Zero Desables this Feature

Ephemeris Data = To get Self Fix the Device must know the Position of Satelite in sky, which is called as Ephemeris Data, This is Combined Database which have there Altitude, Latitude, Longitude so the Phone , GPS Device don't have to wait to get Satellites Position from Frequent Satellite Self Position Broadcast by Air

[AceszHigh]

Didn't read through the whole post...but all you need to do is download nadavi gps tool and theres an option to clear the gps chip of previous locks/locations.

[tichi]

Originally Posted by AceszHigh

Didn't read through the whole post...but all you need to do is download nadavi gps tool and theres an option to clear the gps chip of previous locks/locations.

thnx, I do mention it in the very end of the post, but it does not work for me...

[tichi]

So then, an possible explanation of
the phone being stuck sometimes is the following:

because it tries to update GPS sat positions
using AGPS from an invalid server
(which does not know/not allowed to share the data about Bell towers),
and somehow it never arrives to the idea to search for the new satellites?

[tichi]

Originally Posted by ckl_88

Anyway, have you tried turning off the EnableGPSSmartMode in the SUPL AGPS registry? here is link to the post I'm looking at:

http://forum.ppcgeeks.com/showpost.p...09&postcount=8

updated .. did a few more tests like this:

so I disabled it, soft-reset,, tested GPS, then enabled it, soft reset again, tested GPS, etc...

a few times I got a lock within a minute.. once did not get a lock within few minutes, then GPS froze..

so there seems to be NO difference, and it looks like
the phone DOES NOT download ephemeris data from that Belgium server
and it DOES NOT help to Bell users

????

[ckl_88]

I guess you are lucky in that mine is stuck most of the time! HA HA.

My AGPS settings are basically the same except my GPSMode is at 4.

Anyway, here are my random observations (please bear with me).

1. If I get a fix of about 4 sats, if I turn the GPS unit off (ie. quit all gps apps and put the phone to sleep), after about an hour or two, the time to fix is the same as my cold fix times (1-1.5 minutes).

2. I've been using the latest sprint radio (3.42.xx) for a few weeks now. Ever since then, when I go into Google Maps and select Use GPS, the blue dot puts me in the middle of nowhere. When I say nowhere, I mean a map doesn't even display. all I get is a blue dot on a background of row upon row of magnifying glasses with a minus sign in them. No amount of zooming in or out helps. Then yesterday, I downgraded to the Alltel radio (3.37.10) and tried google maps again. Upon selecting the Use GPS, 10 seconds later, it put me about 4 km from my actual position. Just tried it now and it put me about 1 km from actual position here at work. So my phone, with this radio, is finding my general location. That said, time to fix is still about 1-1.5 minutes.

3. In QPST, I've tried adding the PDE server that was recently discovered from the Telus ROM. On average, my cold fix times haven't changed much. I don't know if Bell users are authorized to use that PDE server or not, but it's not making any difference for me.

Personally, I think the GPS units on Bell phones are falling back to Autonomous mode because the AGPS and PDE servers (from other providers) are not providing the correct information (if at all).

I think that if we can figure out the Bell PDE and AGPS servers then we can expect some pretty quick cold fix times.

BTW, when I did some searching for bell PDE servers, I came across a blackberry forum with Bell users with blackberrys with the same exact problem.... long cold fix times.

[tichi]

Thank you for the info, ckl_88!

> My AGPS settings are basically the same except my GPSMode is at 4.

afaik, it not only tries tro GET the ephemeris data, but also to send them to server, and to fine-tune?
which should make no dofference if the server is not replying anyway...


> 1. If I get a fix of about 4 sats, if I turn the GPS unit off (ie. quit all gps > apps and put the phone to sleep), after about an hour or two, the time
> to fix is the same as my cold fix times (1-1.5 minutes).

an hour is enough to lose a satellite.. makes sense? (their period is
about 12 hours?)

> 2. I've been using the latest sprint radio (3.42.xx) for a few weeks now. > Ever since then, when I go into Google Maps and select Use GPS, the
> blue dot puts me in the middle of nowhere. When I say nowhere, I mean > a map doesn't even display.

coordinates 0.0 0.0 ... Atlantic ocean somewhere near Africa?

> Then yesterday, I downgraded to the Alltel radio (3.37.10) and tried
> google maps again. Upon selecting the Use GPS, 10 seconds later, it put > me about 4 km from my actual position. Just tried it now and it put me
> about 1 km from actual position here at work. So my phone, with this
> radio, is finding my general location. That said, time to fix is still about
> 1-1.5 minutes.

might it be a coincidence? what's the relation between Google Maps and Radio? otherwise from your description it seems that AGPS works with this radio (though you just said it should not work with Bell phones)?

> 3. In QPST,

btw, do not you know where to get this QPST?


> Personally, I think the GPS units on Bell phones are falling back to
> Autonomous mode because the AGPS and PDE servers (from other
> providers) are not providing the correct information (if at all).

so far it is compatible with my obsrervations...

> I think that if we can figure out the Bell PDE and AGPS servers then we
> can expect some pretty quick cold fix times.

would be very cool!