Related
Just curious if anyone else has issues with GPS reception on their sprint touch. I upgraded to the latest htc rom earlier in the week and everything is great except I cannot get GPS to hook up - I've had it work only once.
i upgraded too and i'm using GPS with GoPilot Live, iGO8 and Garmin Mobile XT and it works without issue.
what GPS program are you using with your touch?
Google maps is the only application i've tried. It will search (and search, and search) but doesn't find any or only 1 sat.
Make sure all your settings are correct and try using something like GPS Viewer to get the initilal lock.
Any hint on which settings, and what the the correct values for those settings would be?
Thanks for the tip on GPS Viewer - I will def check it out!
Thanks,
Tim
First, make sure you have the proper Radio/ROM, I assume you do.
Second, under System Settings>External GPS
Programs>COM4 Port
Hardware>(None) Baud Rate>4800
Access>Check Manage Automatically
Third, under Personal Settings>Phone
Services>Location Setting>Location On
Fourth, the Registry
I know of only one value that may help if you change, there are more, but haven't seen them, and I believe it's different on some carriers, like Sprint
HKCU>Software>HTC>SUPL AGPS>GPS Mode
For the inital sat lock, make sure you stand outside on a clear sky and wait at least 5 min, if it takes that long.
The first time I did this, I was trying from inside, finally tried it outside after 3 days of no luck, but now it works quite well. I usually get connected under 30 seconds. As long as your in the same area when you reconnect it should be quick, the first is usually the longest. And I personally use LiveSearch for the directions.
Change from 2 to either 4 or 1, this may help, never really guarenteed though
I was in Boston this weekend and noticed the GPS on my Touch would not lock in a signal in the financial district surrounded by tall buildings. But when I have a clearer view of the sky it works fine. Are you in an open area when you are using it?
hapa_dude said:
I was in Boston this weekend and noticed the GPS on my Touch would not lock in a signal in the financial district surrounded by tall buildings. But when I have a clearer view of the sky it works fine. Are you in an open area when you are using it?
Click to expand...
Click to collapse
It surely helps! Any obstructions will make it harder to pickup the signal.
TheChampJT said:
First, make sure you have the proper Radio/ROM, I assume you do.
Second, under System Settings>External GPS
Programs>COM4 Port
Hardware>(None) Baud Rate>4800
Access>Check Manage Automatically
Third, under Personal Settings>Phone
Services>Location Setting>Location On
Fourth, the Registry
I know of only one value that may help if you change, there are more, but haven't seen them, and I believe it's different on some carriers, like Sprint
HKCU>Software>HTC>SUPL AGPS>GPS Mode
For the inital sat lock, make sure you stand outside on a clear sky and wait at least 5 min, if it takes that long.
The first time I did this, I was trying from inside, finally tried it outside after 3 days of no luck, but now it works quite well. I usually get connected under 30 seconds. As long as your in the same area when you reconnect it should be quick, the first is usually the longest. And I personally use LiveSearch for the directions.
Change from 2 to either 4 or 1, this may help, never really guarenteed though
Click to expand...
Click to collapse
I was having problems with mine too until I did the 4th one and changed it to a 1 from 2 and it works much better. Try it and see you can always turn it back to 2
This helped me
http://www.sprintusers.com/forum/showthread.php?t=173024
My apologies if this has already been posted somewhere. I did a search and came up empty...
So like a lot of people, I've been having some major problems with the GPS's reliability on the Touch (yep, last week's flavor of the week). It connects only when it feels like it, and numerous resets seem to temporarily solve the problem. Well, changing the following registry value seemed to solve all of my problems:
[HKEY_LOCAL_MACHINE\Comm\ConnMgr\Providers\{7C4B7A3 8-5FF7-4bc1-80F6-5DA7870BB1AA}\Connections\Phone as Modem]
"Enabled"=dword:00000000"
Change the value to 0, and soft reset.
It appears that the GPS, by default, makes use of the "Phone as Modem" data connection to take advantage of aGPS, but if a "Sprint PCS" data connection is already active, the GPS doesn't swap connection methods and ultimately hangs. This problem is exacerbated if you have Push services or other data connections running.
I personally haven't noticed any problems with disabling PAM, but as usual, your mileage will vary. For me, I get GPS locks within 15 seconds when I'm in a reasonably accessible location, and I no longer have to reset-and-pray to get this thing working.
bill22 said:
http://www.sprintusers.com/forum/showthread.php?t=173024
Click to expand...
Click to collapse
My apologies if this has already been posted somewhere. I did a search and came up empty...
So like a lot of people, I've been having some major problems with the GPS's reliability on the Touch (yep, last week's flavor of the week). It connects only when it feels like it, and numerous resets seem to temporarily solve the problem. Well, changing the following registry value seemed to solve all of my problems:
[HKEY_LOCAL_MACHINE\Comm\ConnMgr\Providers\{7C4B7A3 8-5FF7-4bc1-80F6-5DA7870BB1AA}\Connections\Phone as Modem]
"Enabled"=dword:00000000"
Change the value to 0, and soft reset.
It appears that the GPS, by default, makes use of the "Phone as Modem" data connection to take advantage of aGPS, but if a "Sprint PCS" data connection is already active, the GPS doesn't swap connection methods and ultimately hangs. This problem is exacerbated if you have Push services or other data connections running.
I personally haven't noticed any problems with disabling PAM, but as usual, your mileage will vary. For me, I get GPS locks within 15 seconds when I'm in a reasonably accessible location, and I no longer have to reset-and-pray to get this thing working.
Link not working, repost.
hate to tell you this, but if you are using the builtin GPS, a clear view of the sky does nothing to improve your gps position locking. our phones have AGPS which means it is fake GPS. It uses the distance from cell towers to triangulate your position, not satellites. Thats why you can get a lock inside with no view of the sky.
some ROMs have different settings on them so following the above directions should work. Or you can do like me and find a better ROM
My Touch Pro ran TomTom flawlessly until a couple of months ago when I got a problem with the GPS device (not the signal) being lost every few seconds. It would reappear again for about 5 secs then off again. Despite soft resets etc, I suspected it might be the SD card at first as I tried many restart combinations with the card in/out etc and as it seemed to help on one occasion I put it down to that. But it did happen on a regular basis.
I now have the X1 with its superb GPS implementation, I was very impressed for a few days... until you guessed it, this problem started happening again!
Luckily I remembered the only setting I had done prior to this occuring was to use the Advanced Config application, where I enabled the AGPS feature. So... I went back in and disabled it and the problem disappeared immediately. I used Advanced Config on the Touch too, so that must have been the problem for sure.
I notice that AGPS is disabled by default. Why HTC did this must mean there is a problem with this feature.
So be advised, not to use the AGPS unless anyone knows good reason to and has a fix for the problem I mentioned.
I ran into the same problem. Turned on agps in advance config, used tomtom 7 and keep getting drop signal. It would pick up the sat signal for a few second and lose it, what interesting though when I use google map it would track me fine, no lost of signal. I can see my "dot" on google map moving along. When I drive, haven't tried it with other nav software to see if this was an issue. I still wonder why they have agps turned off though as default.
i think even if its set to "disabled", its enabled. a-gps must be hard coded in the hardware itself!
ps: i have the same problems when its "enabled".
I think it's the AGPS file that might have corrupted. You can solve this by re-download AGPS file and everything will be fine.
It happened to me once or twice, but it's not a reocurring problem so I did not bother much.
which agps file?
Guess you talk about an A-GPS setting in Tom Tom?
I cannot follow your conversation. With Mobile Navigator, which has no switch to enable or disable A-GPS it works pretty fine.
Sat-fix within seconds - thanks to the provided A-GPS function of the X1, which I don't think can be disabled on teh X1, until you don't update the information frequently with the Quick-GPS application.
Maybe Tom Tom can't interpret the A-GPS information?
How long does a Sat-Fix in Tom Tom take, when you disable A-GPS (in Tom Tom)?
Eric
we are talking about a tool called "advanced config tool". there is an option of enabling and disabling a-gps. "disabled" works best for most users...
you can have a 3d fix in seconds also with no a-gps.
Eric X1 said:
I cannot follow your conversation. With Mobile Navigator, which has no switch to enable or disable A-GPS it works pretty fine.
Sat-fix within seconds - thanks to the provided A-GPS function of the X1, which I don't think can be disabled on teh X1, until you don't update the information frequently with the Quick-GPS application.
Maybe Tom Tom can't interpret the A-GPS information?
How long does a Sat-Fix in Tom Tom take, when you disable A-GPS (in Tom Tom)?
Eric
Click to expand...
Click to collapse
It's incredibly quick (even indoors) to fix a position without AGPS. I admit I haven't knowingly had any noticable problems outside of TomTom but this is something I use a lot. It copes admirably inside, in built-up or shaded areas. No real need for AGPS then! I did try updating my QuickGPS file by the way, to no avail. Disabling was the only fix!
The FIX IS TOO FAST!!!
But I don't have this problem.......
DocMAX said:
we are talking about a tool called "advanced config tool". there is an option of enabling and disabling a-gps. "disabled" works best for most users...
you can have a 3d fix in seconds also with no a-gps.
Click to expand...
Click to collapse
My X1i doesnt have an "adavanced configuration tool" application. Is this a 3rd party addon that you have installed, or is my device just configured differently?
DocMAX said:
which agps file?
Click to expand...
Click to collapse
xtra.bin in \Windows directory I believe
one way to verify if the problem is due to the AGPS corrupted file, is if you encounter the problem, delete the xtra.bin and see if the problem goes away.
kiwiandy said:
My X1i doesnt have an "adavanced configuration tool" application. Is this a 3rd party addon that you have installed, or is my device just configured differently?
Click to expand...
Click to collapse
you have to download it http://forum.xda-developers.com/showthread.php?t=317070
it's our swiss army knife, but be careful
I think people may be getting confused between a-gps and what quickgps does.
My take on this is:
QuickGps downloads a file which contains a list of satellites to speed up getting a signal. Works very well on the x1
this is governed by HKLM/Software/HTC/QuickGPS
A-gps gets an approximate location from your cell tower and feeds 6 virtual satellites signals through the com port set up in the control panel.
It constantly does this, using memory-map software you can see that the signal drops and comes back every second or so. it seems to overwrite what is actually coming from the gps chip as I've seen 4 high quality satellite signals disappear to be replaced with 6 from the a-gps nowhere near where I was.
There's a setting in the registry section concerning A-gps which has "GPSmode" which is set to 2 I wonder what the other values are and do, I havent played with those yet.
You can change the refresh interval I set mine to be 5 when on foot
HKLM/Software/HTC/SUPL_AGPS
I agree with pretty much what you have said (the difference between Quick GPS [sometimes also known as Assisted/A-GPS] and the conventional, location-based AGPS)
However, I don't believe, unless somebody scientifically, or empirically prove, that the phone will receive virtual satellite feed/signal once it acquire the proximity based on the LBS signal. Because to do that, you need to have a data carrier, and it's either via GPRS/UMTS data connectivity (not possible since I would have noticed the data transmission), or radio frequency that satellites transmit on. It can't be GSM/W-CDMA since they operate on the different frequency as GPS, or if it indeed transmit the "virtual satellite signal" on the GSM/W-CDMA network, then I'm sure you will notice it as part of your monthly telco billing?
You may argue that the server is transmitting the virtual satellite signal on the GPS radio frequency, if so, that'll be new development in the AGPS technology since HP iPAQ 6515 first come out employ. However, there are few consideration point;
1. GPS radio frequency does not operate well across barriers, which means the 'virtual satellite transmitter' must be transmitting at a higher ground otherwise it won't work
2. The GPS receiver must be able to reconcile signal from virtual satellite signal and 'real' satellite signal, which means added layer of processing at the phone end, which in my opinions offer more complexity than effective solution.
That said, I just read that the Quick GPS service provider supports 50bit navigation raw data streaming, so I might be wrong afterall.
fards said:
I think people may be getting confused between a-gps and what quickgps does.
My take on this is:
QuickGps downloads a file which contains a list of satellites to speed up getting a signal. Works very well on the x1
this is governed by HKLM/Software/HTC/QuickGPS
A-gps gets an approximate location from your cell tower and feeds 6 virtual satellites signals through the com port set up in the control panel.
It constantly does this, using memory-map software you can see that the signal drops and comes back every second or so. it seems to overwrite what is actually coming from the gps chip as I've seen 4 high quality satellite signals disappear to be replaced with 6 from the a-gps nowhere near where I was.
There's a setting in the registry section concerning A-gps which has "GPSmode" which is set to 2 I wonder what the other values are and do, I havent played with those yet.
You can change the refresh interval I set mine to be 5 when on foot
HKLM/Software/HTC/SUPL_AGPS
Click to expand...
Click to collapse
zenkinz said:
I agree with pretty much what you have said (the difference between Quick GPS [sometimes also known as Assisted/A-GPS] and the conventional, location-based AGPS)
However, I don't believe, unless somebody scientifically, or empirically prove, that the phone will receive virtual satellite feed/signal once it acquire the proximity based on the LBS signal. Because to do that, you need to have a data carrier, and it's either via GPRS/UMTS data connectivity (not possible since I would have noticed the data transmission)
Click to expand...
Click to collapse
when you enable a-gps in the registry it establishes a data connection, or at least it does on my phone.
In my house I get a variable signal, it can drop the data connection easily (and does)!
When I first tried A-gps enabled in the registry it tried to connect, couldnt and memory-map reported no signal. It then connected I got 6 satellites listed till the data connection dropped. This makes me think it's using a data connection.
I disabled all data connections using paul modacos "nodata" and didn't get any "satellites" picked up. My quickgps was upto date at the time and outside I would expect to get a decent "proper" satellite lock.
the SUPL-AGPS section of the registry also contains the following.
Server IP 10.1.101.63
Server Port 7275
Which suggests some form of data connection. Remember this has nothing to do with quickgps or the ephemeris data that gets.
Have a look at http://wmexperts.com/articles/gps_vs_agps_a_quick_tutorial.html
&
http://en.wikipedia.org/wiki/GPS_Phone
A typical A-GPS-enabled cell phone will use a data connection (internet, or other) to contact the assistance server.
Click to expand...
Click to collapse
-----------------------
edit Have just tried again to confirm what I wrote and not getting anything through a-gps at all! I wonder if there's something in this custom rom that's changed things.
But I am being told Ive got a HDop of 666.6m which is a bit spooky..
step outside and I got 9 satellites with 8m hdop back inside and I'm getting standard fix 5 sats 2m HDop flashing on and off every second (signal/no signal) but no data connection being used, so it looks like I'm wrong, so I'll take it all back!
Need to work out what's going on now..
I was having this same issue. At least its good that its not just my device. I tried deleting xtra.bin from both \windows and \temp and it did not help.
Just some clarification on QuickGPS and AGPS. For a regular stand alone GPS to connect, when it first finds a satellite it must download ephemeris data. The ephemeris data contains info about where all the GPS sats currently are in the sky. The ephemeris data is broadcasted by every satellite periodically. A regular GPS must wait for the beginning of the next transmission. If signal is lost mid transmission, the GPS reciever must wait for the next transmission and start all over again. Only once this data is downloaded can a lock begin to be calculated. What quickGPS does is download the ephemeris data from the internet so that next time you request a gps lock, this sometimes lengthy process can be skipped. quickGPS downloads a file called packed ephemeris and places it I believe in the windows directory.
AGPS on the other hand simply supplements info from the sattellites with info from the cell network. What towers you are currently near gives an approximate location (the mechanism that google my location uses) which then tells you which satellites to look for. When fards said it feeds virtual satellite info, he doesn't mean it actually broadcasts fake satellites via RF. It just feeds extra info to the GPS driver. Also, there are lots of calculations to do to maintain a lock. Once the receiver is getting sattelite signals it can send this information over the internet to the AGPS server which is a much more powerful computer that can do these calculations much faster. The server calculates the lock for you then sends you your position information back over the internet. This is why apgs enables a data connection.
Hi,
Could anyone please explain the various settings for GPS in the "settings" menu (under "location")? I find that the manual and tooltips are not very informative.
Particularly, I don't understand the difference between the first choice ("wireless networks"?) and the third choice ("assisted GPS"). I understand that the phone may use wifi or mobile network to detect my position (instead of or in addition to GPS satelites), but I don't know which of the two options to choose for this.
Also: When I enable "wireless networks", what does the warning that pops up mean? It mentions that data will be collected even when no software (GPS/map) is running. What is that? And what is the difference between enabling this and the fourth option ("share with google")?
Finally:
Does your GPS immediately start working when you enable it? Myself, I need to enable/disable GPS using the desktop widget and the various GPS settings several times before it managess to find my location. (My position is not the problem - once detected/connected, it works fine.) I still don't understand which combination of settings it is that finally makes the GPS work as expected.
As I understand the first option "Wireless Neworks" will rely entirely on data from Cell Towers e.t.c to determine your position. I guess this will be less accurate.
"Assisted GPS" enables your device to get a faster lock on your location by collecting available data from cell towers first before using the GPS receiver.
I think if you were only to activate the GPS in some circumstances it would take a lot longer to get a fix.
"Share with Google" just allows the gears addon within the browser to share your position with google allowing them to return results based on your location.
That's my take on those options.
"Wireless Neworks" - is using cell towers and wifi to locate you.
Probably they have (or use a 3rd party DB) for that. Anyway, is not (very) accurate.
"Assisted GPS" - i'm not 100% sure but i think is connecting to a location server to get the location of the GPS satellite so, will lock faster (at least this is what my Nokia 5800xm is doing).
The warning message you get is because google will (most likely) use your location (cell towers and wifi spots) to create and update their own database so, phones without GPS will still be able to use google maps.
Well, they probably do something more with that data but who knows what
I just wanna add that using any type of assistance for the gps chip in this phone is (in my personal oppinion) unnecessary. I am sitting inside my house, in my bed(with a window behind me) an in 10sec i get fixed on 10 satellites. Not much that can beat that ;-)
in addition, i am in the bottom floor in a 2floor house so it is alot of roof and cealing between me and the sky.
Sent from my X10i using the XDA mobile application powered by Tapatalk
Thanks for your replies. Much appreciated.
Just curious - which app do you use to monitor GPS satelites?
Also, does everyone's GPS find your location rather quickly after enabling GPS? I usually get the message "Your current position is temporarily unavailable", I retry, same result, I retry, same result ... Only after I disable/enable GPS several times, my position can be found.
My GPS usually finds my position rather quickly first time I switch on GPS. I have aGPS (Assisted GPS) enabled too, this way your phone gets help on locating the sattelites position from your mobile provider, hence locking onto GPS signal faster (is to my understanding).
Plus, if you're standing in an area with tall buildings, your position will be less accuratelly pin-pointed, bouncing GPS signal and all.
I'm using GPS test by chartcross ltd. Avalible in the free android market, and i really like it!
Sent from my X10i using the XDA mobile application powered by Tapatalk
I never turned on A-GPS on this phone. There is no need for A-GPS.
This phone have fastest GPS fix of all phones.
I have noticed when I am running on 3G (H) I get the "location temporarily unavailable" notice, but if I force it to not go to 3G it will be E and I get my location. This holds true if I have setting for using GPS or not.
This seems to be a problem with Google Maps using the data transfer method of 3G (H) versus E.
Hello,
I was wondering if anyone was familiar with the control plane option in SUPL settings.
The reason I ask is that I was playing around in the secret code area of SG Tools and noticed an area marked GPS
SGS Tools -> Secret Codes -> ServiceMode, Debug, Netz, Audio, Common -> Common -> GPS -> Display and Change CP Status.
I enabled the Control Plane and then set SUPL settings in lbstest to supl.google.com etc and change SUPL Mode to Control Plane. My gps has been crazy awesome since then. Also change application settings Accuracy to 25.. I do have the jupiter file gps fix installed but GPS would still loose me until I made these changes. I was hoping someone could explain Control Plane and or someone would test these settings for themselves and let me know how it works. I am running Axura Beta 5 with Setiron Kernel 1.4.2
None of those settings "fix" GPS.
Thanks for the reply. Are you aware of what the control plane setting is for?
Not that I'm actually interested in this "fix", but is your "crazy awesome" GPS just giving you faster initial position locks?
Getting a position lock is one thing, but having the GPS actually be able to track your movement and be accurate is different...which many overlook when they say their GPS works. If you were to use to Captivate in the car to navigate with, would it be accurate? If you can say yes to that, you could consider your GPS working then.
norcal einstein said:
Not that I'm actually interested in this "fix", but is your "crazy awesome" GPS just giving you faster initial position locks?
Getting a position lock is one thing, but having the GPS actually be able to track your movement and be accurate is different...which many overlook when they say their GPS works. If you were to use to Captivate in the car to navigate with, would it be accurate? If you can say yes to that, you could consider your GPS working then.
Click to expand...
Click to collapse
I am getting faster locks.. more sattelites.. I also tested while driving and it stayed good the entire time.. I am going to test again on my hour drive home tonight..
Sent from me to you over wires using only 1's and 0's
Also my main interest is in finding out more information on what this setting does as well. It is my opinion that this has helped and I wanted more imformation and also to see if it helps qnyone else..
Sent from me to you over wires using only 1's and 0's
+1
I dunno why but set as control plane gives me more sats and faster locks even better tracking.
This is the first thing i do every time after flashing a new rom to my cappy.
ms base mode, google supl sever with control plane mode and secure socket off.
Sent from ATT Captivate operated by Perception build 5
drancid said:
+1
I dunno why but set as control plane gives me more sats and faster locks even better tracking.
This is the first thing i do every time after flashing a new rom to my cappy.
ms base mode, google supl sever with control plane mode and secure socket off.
Sent from ATT Captivate operated by Perception build 5
Click to expand...
Click to collapse
Have you checked to see if the control plane is enabled via sgstools?
Sent from me to you over wires using only 1's and 0's
mpencexda said:
Have you checked to see if the control plane is enabled via sgstools?
Sent from me to you over wires using only 1's and 0's
Click to expand...
Click to collapse
nope but i'll check it now..
Sent from ATT Captivate operated by Perception build 1
Control Plane is an alternative method of accessing the AGPS server from User Plane (SUPL). Control Plane goes over the cellular providers Control Plane (fancy that!) whereas SUPL goes out over the GPRS network (HSPA, 3G, etc.)
For Control Plane to work, the cellular provider has to have in place specific technology intended for use with AGPS. All older AGPS solutions prior to the deployment of SUPL use Control Plane. Basically it's "the old way"
Note that you can obtain the exact same AGPS data through a SUPL connection to the same set of servers AT&T maintains. This is the default setting for "Server FQDN Type" - AUTO Config.
Basically, setting it to AGPS Mode - Control Plane (regardless of other server settings) is the same as setting AGPS Mode - SUPL, SUPL Secure Socket - ON, Server - h-slp.mnc410.mcc310.pub.3gppnetwork.org, Server Port - 7275. AND is also the same as using "Server FQDN Type" - AUTO Config, providing your cellular provider is AT&T (MNC 410 MCC 310).
Note that the specifications for AUTO Config will read the MCC/MNC of your network provider (in my example above, AT&T) and change the mncXXX.mccYYY part to match your providers MNC/MCC. Per the 3gpp SUPL spec, when in a home network, the URL to access for SUPL services is h-slp.mncXXX.mccYYY.pub.3gppnetwork.org, which breaks down to:
h-slp - Home SUPL Location Platform
mncXXX - MNC of the current network the phone is parked on
mccYYY - MCC of the current network the phone is parked on
pub.3gppnetwork.org - A (purposefully) un-registered domain name free for use by cellular providers.
When you are roaming, the URL changes to:
v-slp.mncXXX.mccYYY.pub.3gppnetwork.org
where v-slp instead means Visiting SUPL Location Platform.
So, to sum that up, if your cellular provider is following 3gpp SUPL recommendations properly, when you attempt a SUPL connection to h-slp.mncXXX.mccYYY.pub.3gppnetwork.org, your cellular provider should connect you to THEIR provided SUPL server. In the case of AT&T this is fully functional. Note that this will NOT work on Wi-Fi, the DNS will not resolve (since you aren't connected to a cellular network, the ISP you're on will not maintain a SUPL server for you, unless they are just THAT nice)
Note that if you use a program like MarketAccess to change your MNC/MCC to allow access to other markets, the SUPL address will also change (to reflect the altered MNC/MCC) and thus be broken in automatic mode.
Anywho, all of this only affects the initial lock time, when set to MS-Based. (Defaults on the stock ROM to standalone, which doesn't use AGPS at all, and sane people will use MS-Based)
Tracking once you have a lock should NOT be affected by any of these changes.
In case you're wondering where I got my information, it's not my first go-round to this particular party. I did all the legwork for this a bit over a year ago, and put up a compendium post about it in March 2009: http://forum.xda-developers.com/showthread.php?t=489887 All the info I reference from the SUPL specifications is obtained by spending hours reading the actual, incredibly boring whitepapers.
I haven't had time to properly devote to the GPS problem for captivate like I have for previous WM devices (I just got the cappy), but i'm guessing there's some errors in either the satellite correlation done in the baseband, or in the driver's interpretation of the output in the kernel code. It might also be the case that the phone is relying on a clock generator that isn't putting out the exact cycles they have it programmed for, thus introducing clock drift into the correlation algorithm. The clock has to be precise and synced up to the GPS clocks in order to properly trilaterate location. This might explain the drift over time and then snapping back to a real location once the clocks are properly synced again. (GPS satellites send the complete information required to sync a clock accurately every 12.5 minutes.)
Do note that the clock i'm referring to is the internal GPS reference clock, which is not related in any way to the time set on the device. Internally, the device does keep track of the offset between GPS time and Device Time, but Device Time is not used in the GPS calculations (a different internal clock is used, and synced to the satellites themselves with each transmission) - Previously it has been suggested that ensuring the phones clock is as accurate as possible would make a difference, but that is not the case (due to it not being the same clock)
Either way, any changes to gps.conf or secgps.conf aren't gonna cut the mustard with this particular issue. Initial fix time and number of initial sats, sure. But once the GPS is fired up and running, and has time to pick up a constellation update from the satellites, you're in the same boat as anyone else.
BTW. You can read the adb logcat output to easily see if your phone is utilizing AGPS. You will get an initial fix with an accuracy of appx. 1500m and the log will show that it is not a GPS fix but instead a network provided location. It will then show this location being injected into the GPS driver (AGPS)
Thanks for the info.. that was amazing. I really hope that you get some time to devote to this as you seem informed
Sent from me to you over wires using only 1's and 0's
Thanks
DA G,
Thanks for the information, glad to have you in cappy land!
Da_G said:
Control Plane is an alternative method of accessing the AGPS server from User Plane (SUPL). Control Plane goes over the cellular providers Control Plane (fancy that!) whereas SUPL goes out over the GPRS network (HSPA, 3G, etc.)
For Control Plane to work, the cellular provider has to have in place specific technology intended for use with AGPS. All older AGPS solutions prior to the deployment of SUPL use Control Plane. Basically it's "the old way"
Note that you can obtain the exact same AGPS data through a SUPL connection to the same set of servers AT&T maintains. This is the default setting for "Server FQDN Type" - AUTO Config.
Basically, setting it to AGPS Mode - Control Plane (regardless of other server settings) is the same as setting AGPS Mode - SUPL, SUPL Secure Socket - ON, Server - h-slp.mnc410.mcc310.pub.3gppnetwork.org, Server Port - 7275. AND is also the same as using "Server FQDN Type" - AUTO Config, providing your cellular provider is AT&T (MNC 410 MCC 310).
Note that the specifications for AUTO Config will read the MCC/MNC of your network provider (in my example above, AT&T) and change the mncXXX.mccYYY part to match your providers MNC/MCC. Per the 3gpp SUPL spec, when in a home network, the URL to access for SUPL services is h-slp.mncXXX.mccYYY.pub.3gppnetwork.org, which breaks down to:
h-slp - Home SUPL Location Platform
mncXXX - MNC of the current network the phone is parked on
mccYYY - MCC of the current network the phone is parked on
pub.3gppnetwork.org - A (purposefully) un-registered domain name free for use by cellular providers.
When you are roaming, the URL changes to:
v-slp.mncXXX.mccYYY.pub.3gppnetwork.org
where v-slp instead means Visiting SUPL Location Platform.
So, to sum that up, if your cellular provider is following 3gpp SUPL recommendations properly, when you attempt a SUPL connection to h-slp.mncXXX.mccYYY.pub.3gppnetwork.org, your cellular provider should connect you to THEIR provided SUPL server. In the case of AT&T this is fully functional. Note that this will NOT work on Wi-Fi, the DNS will not resolve (since you aren't connected to a cellular network, the ISP you're on will not maintain a SUPL server for you, unless they are just THAT nice)
Note that if you use a program like MarketAccess to change your MNC/MCC to allow access to other markets, the SUPL address will also change (to reflect the altered MNC/MCC) and thus be broken in automatic mode.
Anywho, all of this only affects the initial lock time, when set to MS-Based. (Defaults on the stock ROM to standalone, which doesn't use AGPS at all, and sane people will use MS-Based)
Tracking once you have a lock should NOT be affected by any of these changes.
In case you're wondering where I got my information, it's not my first go-round to this particular party. I did all the legwork for this a bit over a year ago, and put up a compendium post about it in March 2009: http://forum.xda-developers.com/showthread.php?t=489887 All the info I reference from the SUPL specifications is obtained by spending hours reading the actual, incredibly boring whitepapers.
I haven't had time to properly devote to the GPS problem for captivate like I have for previous WM devices (I just got the cappy), but i'm guessing there's some errors in either the satellite correlation done in the baseband, or in the driver's interpretation of the output in the kernel code. It might also be the case that the phone is relying on a clock generator that isn't putting out the exact cycles they have it programmed for, thus introducing clock drift into the correlation algorithm. The clock has to be precise and synced up to the GPS clocks in order to properly trilaterate location. This might explain the drift over time and then snapping back to a real location once the clocks are properly synced again. (GPS satellites send the complete information required to sync a clock accurately every 12.5 minutes.)
Do note that the clock i'm referring to is the internal GPS reference clock, which is not related in any way to the time set on the device. Internally, the device does keep track of the offset between GPS time and Device Time, but Device Time is not used in the GPS calculations (a different internal clock is used, and synced to the satellites themselves with each transmission) - Previously it has been suggested that ensuring the phones clock is as accurate as possible would make a difference, but that is not the case (due to it not being the same clock)
Either way, any changes to gps.conf or secgps.conf aren't gonna cut the mustard with this particular issue. Initial fix time and number of initial sats, sure. But once the GPS is fired up and running, and has time to pick up a constellation update from the satellites, you're in the same boat as anyone else.
BTW. You can read the adb logcat output to easily see if your phone is utilizing AGPS. You will get an initial fix with an accuracy of appx. 1500m and the log will show that it is not a GPS fix but instead a network provided location. It will then show this location being injected into the GPS driver (AGPS)
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Da_G? In my Captivate thread? This brings me back to playing with with GPS on the HTC Touch Pro...
It's crazy that was 2 years ago.
Hi, CLShortFuse, long time no see
Actually i've been lurking for a while now, just trying to learn things before I get down to the nitty gritty of modding source code (and writing some new stuff of my own!)
To be fair, I was a GPS fan before I became a PDA fan I remember doing firmware hacks to the SirfStar III chipset to enable functionality above 18,000m, faster than 515m/s, and bypassing the acceleration and motional jerk limiters Why? Because my GPS should work to its full ability, dammit!
As I understand, we don't have access to any of the baseband source. This is probably where a large amount of the GPS calculations are handled (It is so with Qualcomm, at least) and so it may not be something we can address. But a good thorough look at the kernel driver(s) should answer that question.
I wonder if the chipset is even SBAS Capable (WAAS/EGNOS, i'm quite sure it doesn't have a receiver for any land based solutions). The accuracy reminds me of GPS back in the days when Selective Availability was up (artificial GPS accuracy limitations put in place by the military) before DGPS came about.
Ironically, my hacked bluetooth GPS from 2005, a Globalsat BT338 remains the most accurate consumer level GPS I have used to date, with accuracies down to .3 meters in ideal conditions. (During normal in the field conditions like stuck in a backpack, in the back seat of a car, with perhaps a 5 degree view of the sky, and wicked multipath from skyscrapers it's accurate to around 2 meters) - basically, you can count on it to be accurate down to what lane of traffic you are in
The same chipsets are made available to smartphone manufacturers. (The current model being the SirfStar IV, and capable of even better accuracy than that older one) - I only wish more manufacturers would actually use them!
I actually currently use that BT GPS for any navigation I do. But nonetheless, we don't have such a nice platform to work with, so let's see what we can do with what we have Perhaps tomorrow i'll take a drive with 2 captivates, both loaded to stock firmware (updated to the "gps fix" build) + the samsung GPS fix on the market (which we know is worthless, but just for S&G)
I'll record raw NMEA output from both GPS units (Captivate using internal GPS, and Captivate using BT-338 GPS through bluetooth serial NMEA), and post that up along with a google earth .kml for easy comparison. The difference between the two is quite striking. I'll be using that GPS unit as my baseline for "great performance" when the hackery begins
(edit: taking a quick look at the kernel source it looks like we have a BCM4751 and i'm fairly certain all the relevant calculations are handled in the baseband. The good news is that chipset does support SBAS. I doubt it's properly handling it however, as it doesn't even perform up to the level of a GPS without SBAS. If everything IS being handled in baseband, i'm going to need to get my hands on source code to the radio to fix it, which won't be the easiest thing ever )
Getting interesting now...
Did anyone come across this yet? Is this real or a joke?
Samsung Captivate And Vibrant Finally Get GPS "Fix" Via GPSSamsungRestore App
The Galaxy S phones are, without a doubt, among the best Android phones out there, but for some time now, the handsets have been plagued by one potential showstopper – malfunctioning GPS capabilities. Worry not, though – in addition to an update that rolled out a few months ago, Samsung has developed an app called GPSSamsungRestore which is now available from the Android Market for all users of AT&T’s Captivate and T-Mobile’s Vibrant. So what does it do? It undoes any modifications to the GPS and basically reverts it to its original state. While it remains to be seen how reverting the GPS to its original, broken state fixes it, I suppose it can’t hurt to give it a shot if you’re a Captivate or Vibrant owner.
Note: The app only shows up in the Market for Captivate and Vibrant owners, so if you’re looking for it just for kicks, you won’t find it unless you’ve got one of those devices. It isn’t listed on AppBrain, either.
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Click to collapse
Quote from Android Police
Is there a validity with that GPSSamsungRestore fix.
and +1 on awesome person joining this awesome group!
Wow..very informative read there. Looks like we've found our Cappy GPS fixer-upper! Nice to have you aboard.
Sent from my couch on my phone.
Da_G I'm glad to see you have a captivate. Used your roms all the time on my Touch Pro. Glad to see another great dev on this phone. Looking forward to any work you do with it.
Amazing explanation, we are all aware of the AGPS -GPS relation but we like to lie to ourselves that some of these tweaks are actually working and that our devices are as good as any other. The truth is that our device is waaaay better with the latest developments than any other device on the market, and mine is simply perfect.
Honestly, I've been running Cognition 2.3b6 with the Jupiter v6 tweaks and had no problems with the GPS on a trip in the mountains, between trees and under heavy snow (300km round trip). Absolutely none! A bit slow lock but great tracking.
Now I'm using 2 different tweaks, the JM9 GPS drivers + this control plane thing on the same rom, Cog 2.3b6. Got a lock in 10-15 sec on 7 sats (tested for about 10 mins) but didnt have the chance to take it for a test drive. Hopefully will get the same results like before. If not, I'll just revert back to "stock" Cog with jupiter tweaks, that was the best.
Hi,When I use my phone for finding my location without using data connectivity - without relying on A-GPS so my phone finds my location after a lot of time or sometimes google maps can't find my location.
How can I solve this?
Thanks.
After day or so it won't get fix at all. Samsung just did something wrong I'm afraid. Looks like the GPS in SG2 NEEDS data to work. I found the hard way on my trip to Japan. I know no solution.
So I cant change my gps settings?
Sent from my GT-I9100 using XDA App
GPS in the S2 is weird. Some days it locks in seconds other times it takes forever. I never use A-GPS.
Today I couldn't get it to lock but last night it was instant. So I restored a CWM backup from last night, rebooted and it locked instantly.
I played around with MIUI for a couple of days and found lock time much better than stock or custom rom.
Also, changing server with fasterfix makes no difference when its having problems locking.
I just don't get it.
Sent from my GT-I9100 using XDA Premium App
GPS Aids in Market. It will take a bit of time on first lock but from then it will be fast.
sxi200 said:
GPS in the S2 is weird. Some days it locks in seconds other times it takes forever. I never use A-GPS.
Today I couldn't get it to lock but last night it was instant. So I restored a CWM backup from last night, rebooted and it locked instantly.
I played around with MIUI for a couple of days and found lock time much better than stock or custom rom.
Also, changing server with fasterfix makes no difference when its having problems locking.
I just don't get it.
Sent from my GT-I9100 using XDA Premium App
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Click to collapse
How do you 'never use AGPS' ? Btw. my problem is not time of the lock. But the fact, that without network, I don't get fix AT ALL. With network AGPS reset helps (many apps can do that). But without network GPS works only for some time (AGPS data still valid). After that you just won't get fix. It even looks like wifi connection won't help, it has to be mobile network.
It's because of crappy gps reciever or it can be improved by another rom?
Thanks
Sent from my GT-I9100 using XDA App
It seems the problem is that GPS is in mode, where it simply relies on AGPS. In older ROMs there was app called LBSTestMode where you could change the mode to stand alone, or just AGPS based. This application is not in newer ROMs, so it cannot be switched. It clearly is just a software thing. Except it looks that there is no solution which does not involve flashing roms and/or rooting.
Dr.Sid said:
How do you 'never use AGPS' ? Btw. my problem is not time of the lock. But the fact, that without network, I don't get fix AT ALL. With network AGPS reset helps (many apps can do that). But without network GPS works only for some time (AGPS data still valid). After that you just won't get fix. It even looks like wifi connection won't help, it has to be mobile network.
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Click to collapse
Yeah I never use it. I don't tick 'use wireless networks' at all. To me that's fake GPS.
Since my last post, GPS has been perfect. Am able to lock up to 11 satellites sitting on the couch. On average it takes about 10 seconds to lock. Tested it at least 20 times today.
But who knows what will happen tomorrow!!!
Man, if you can only get a lock using wireless networks then I think your GPS might be stuffed.
Sent from my GT-I9100 using XDA Premium App
sxi200 said:
Yeah I never use it. I don't tick 'use wireless networks' at all. To me that's fake GPS.
Since my last post, GPS has been perfect. Am able to lock up to 11 satellites sitting on the couch. On average it takes about 10 seconds to lock. Tested it at least 20 times today.
But who knows what will happen tomorrow!!!
Man, if you can only get a lock using wireless networks then I think your GPS might be stuffed.
Sent from my GT-I9100 using XDA Premium App
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Click to collapse
That does not mean you don't use AGPS. AGPS is method, where data about GPS satellites are not downloaded from those satellites via GPS receiver, but rather from server via. mobile network. So I'm afraid you do use AGPS, unless you disable mobile networking (and wait about day for current data to become obsolete).
One thing I've noticed is that when I run Z-DeviceTest and bring up the GPS status display, it shows that none of the satellites have almanac data, and very rarely have ephemeris data. If that's accurate, that would suggest that if you've turned off AGPS and mobile networking, you could have some trouble.
3waygeek said:
One thing I've noticed is that when I run Z-DeviceTest and bring up the GPS status display, it shows that none of the satellites have almanac data, and very rarely have ephemeris data. If that's accurate, that would suggest that if you've turned off AGPS and mobile networking, you could have some trouble.
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Click to collapse
Nice find. First app I know which shows this. Now I can test if that almanac is downloading via GPS satellites or not.
Dr.Sid said:
That does not mean you don't use AGPS. AGPS is method, where data about GPS satellites are not downloaded from those satellites via GPS receiver, but rather from server via. mobile network. So I'm afraid you do use AGPS, unless you disable mobile networking (and wait about day for current data to become obsolete).
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Ok. So does that would mean it's impossible to get a GPS lock without data enabled? Or just harder to?
Maybe I shouldn't have mentioned AGPS, but instead wireless networks which show your position even though GPS is not locked.
Sent from my GT-I9100 using XDA Premium App
sxi200 said:
Ok. So does that would mean it's impossible to get a GPS lock without data enabled? Or just harder to?
Maybe I shouldn't have mentioned AGPS, but instead wireless networks which show your position even though GPS is not locked.
Sent from my GT-I9100 using XDA Premium App
Click to expand...
Click to collapse
It seems it may vary with ROM, and it is possible to switch it, at least older ROMs contain service menu module (LbsTestMode) to switch it. But my SG2 seems to be unable to get a fix without network. It simply does not even try do download Almanac or Ephemerides data from the satellites.
Also for AGPS, mobile network must be used, not WiFi. As I understand it, those AGPS server names are virtual, and network provider redirects them based on location .. which is not possible via WiFi.
I wonder WHY there is such option at all. Do mobile network providers want us to be unable to get a fix without them ?
Dr.Sid said:
It seems it may vary with ROM, and it is possible to switch it, at least older ROMs contain service menu module (LbsTestMode) to switch it. But my SG2 seems to be unable to get a fix without network. It simply does not even try do download Almanac or Ephemerides data from the satellites.
Also for AGPS, mobile network must be used, not WiFi. As I understand it, those AGPS server names are virtual, and network provider redirects them based on location .. which is not possible via WiFi.
I wonder WHY there is such option at all. Do mobile network providers want us to be unable to get a fix without them ?
Click to expand...
Click to collapse
Hey Dr, I think you have diagnosed my problem
Every so often I turn off data and use only wifi. One day my GPS locks in seconds then the next it takes forever.
So I have now tested it a couple of times over the last couple of days, when I can't get a lock I turn off wifi and turn on data. All of a sudden GPS locks again. Interesting!!
Hopefully that is it. Will test again the next time it won't lock.
Sent from my GT-I9100 using XDA Premium App
Ha ! Breakthrough. I could get a fix without network ! But ..
I used newer version of 'GPS Status' app. It shows state of unconnected satellites with gray/blue/yellow based on how much data it has - none/almanac/ephemerides. So you can see if there is some progress or not.
So I disabled network (both wifi and mobile), disabled location from mobile network, left just GPS on .. run GPS status and used 'Reset AGPS'.
The connection has few 'phases':
1) you get signals from satellites .. you see it in power meter .. all are gray .. and their dots on the 'sky' view are all in the N. Sure, GPS does not know where the satellites are, and does not know where you are .. so it can't know where on the 'sky' they should show.
2) Some signals/dots turn blue. That means you have almanac data. Rough position of all satellites, which is transmitted by all satellites. That already means your GPS receiver was used to download some data from the satellites. Based on this, GPS can tell very roughly where you are, and will paint dots on the skyview.
3) Some signals/dots turn yellow. That means you successfully downloaded ephemerides data from that satellite, and it can be used in fix. Have enough of them, and you are done.
4) Some signals/dots turn green - you have fix. The error will get better over time as more satellites are used.
I took me over 5 minutes .. but thanks to this tool I could see I'm indeed receiving some data and there is some progress. Also it only worked outside, under open skies. I tried that in a car, in a bus, in a train .. after 10 minutes I did not get over phase 1. With AGPS I get fix in all such situations in few seconds.
It just looks like the data decoding module for almanac/ephemerides is not the same as for the time (which is used in fix itself). While time channel is quite sensitive and fine, data channel seems to have troubles with even slightest disturbances.
Still I'm happy I made it work in the end !
Btw. the fact that AGPS does not work over WiFi still holds.
ayosopov said:
Hi,When I use my phone for finding my location without using data connectivity - without relying on A-GPS so my phone finds my location after a lot of time or sometimes google maps can't find my location.
How can I solve this?
Thanks.
Click to expand...
Click to collapse
try fasterfix from market
I rarely have the data connection on (just to save battery) and WiFi is only on where I know I have a known connection - thus it is off when outside.
I put on the GPS then immediately run Sygic satnav program. I will have a fix normally within 30 seconds and a worst case of about a minute (that I can remember).
I have just tried switching off and on my phone, putting on the GPS (from the Pull down menu) and run Sygic. From switching on the GPS, I had a lock in about a minute.
KI3 Stock ROM
fred_up said:
I rarely have the data connection on (just to save battery) and WiFi is only on where I know I have a known connection - thus it is off when outside.
I put on the GPS then immediately run Sygic satnav program. I will have a fix normally within 30 seconds and a worst case of about a minute (that I can remember).
I have just tried switching off and on my phone, putting on the GPS (from the Pull down menu) and run Sygic. From switching on the GPS, I had a lock in about a minute.
KI3 Stock ROM
Click to expand...
Click to collapse
Could you try that with AGPS manually reset ? I recommend 'GPS Status' tool to do it, it's in 'tools' menu.
GPS lock time seems much improved in KJ4 firmware for me (i'm on orange 2.3.5)
all three DOP values in GPS Status now show figures (instead of infinity for two of them), and i'm getting reported accuracies of around 5 metres, instead of 14 - 20 metres on the older firmware.