GPS Settings: Performance Options (improvement)

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shaneaus

Senior Member
Nov 27, 2007
547
18
Austin, Texas
Ok, There are a lot of posts and information regarding the GPS issue that some are experiencing. I am starting (yet) another post in the interest of compiling and maintaining information regarding that information in one location. As users/devs find out information I will update this post so everyone doesn't have to go looking everywhere for the information. I am hoping that the Moderator will sticky this post.

Some users are experiencing very long lock times for their GPS. Everyone, after reading A LOT of posts/threads it seems to be the consensus that this is a software/settings issue - NOT, a hardware issue. However, results from tweaking the following settings are very mixed. Most seem to get great results by tweaking the following settings while stationary - but, moving is a whole different ball game. I use the below settings and have great results while stationary. However, my G1 blows the Captivate completely out of the water!!! My G1 gave 3-10m accuracy while driving. This device can barely keep me on the correct highway and always seem lagging behind my current location. The G1 was spot on no matter what. What hasn't been determined is if these issues are hardware or software. For whatever my opinion is worth - I think it is a firmware/software issue. Here are some things to try.

Here is the info:

To get to your GPS settings open you dialer and dial the following number. This will not call anyone - it is a code shortcut to the settings:
*#*#1472365#*#*

Once entered you will observe a screen that has five buttons:
Get Position Test
Application Settings
SUPL/CP Settings
Test Application
Delete GPS Data


We will be interested in three of these initial buttons.

Get Position Test: This will be what one uses to test the results of your changes.

Application Settings: Exactly what it says.

SUPL/CP Settings: settings that determine specific data connectivity with the satellites.

In Application Settings the following are some that you might consider adjusting:
Operation Mode - Standalone, MS Based, MS assisted, Network Provider
Accuracy - defaults to 50. Don't set it below 10 (and only use increments of 10's)
SkyHook - not sure what it does. But, someone on a thread mentioned it and it DOES effect satellite lock times.

In SUPL/CP Settings one we'll be interested in the following:
Server FQDN Type
Server
Server Port



The following are the options provided on other threads:

Original/Stock Settings:
SUPL/CP Settings/SErver FQDN Type/Custom Config
Application settings/Operation Mode/Standalone
SUPL/CP Settings/Server/www.spirent-lcs.com
SUPL/CP Settings/Port/7275

Second suggested setup (from other posts and claimed to have great results):
SUPL/CP Settings/SErver FQDN Type/Custom Config
Application settings/Operation Mode/MS Based
SUPL/CP Settings/Server/supl.google.com
SUPL/CP Settings/Port/7276

Other settings that I have played with:
Application settings/SkyHook/On (and Off)
SUPL/CP Settings/SErver FQDN Type/Auto Config (and Custom Config)

You can play around with these to see what gives you the best results. If your GPS doesn't work better with whatever changes you made - than you can always put it back to the orginal settings above.
However, it has been recommended and I concur (for whatever that is worth) that you NEED TO SET THE FOLLOWING BEFORE YOU START PLAYING AROUND: Settings/Location and security/uncheck (turn off) "Use Wireless Networks). Most likely this won't really effect anything while your testing within the GPS settings - however, this will effect your results if you test using Google Maps, etc.

Now, having duly noted all of the above and having played around with the settings for several hours I found the best results FOR MY DEVICE IN MY AREA AT ONE LOCATION was the following:

Note: I adjusted these settings from earlier as the earlier settings proved to be very accurate when stationary - but, very inaccurate while moving. The latest settings I'm using are below. Also, look to the bottom of this post regarding changing your gps configuration file. That also helped A LOT. The bottom section of information is from the Official websites that run the time servers(effects GPS performance).

Application Settings/Operation Mode/MS Based
Application Settings/Operation Mode/SkyHook/ON (VERY IMPORTANT)
SUPL/CP Settings/Server FQDN Type/Custom Config
SUPL/CP Settings/Server/supl.google.com
SUPL/CP Settings/Server Port/7276
SUPL/CP Settings/SUPL Secure Socket/Off


Turning "SkyHook" ON assisted in faster locks with ALL of my tested settings when stationary!

My test results with the above would lock on up to three satellites in under four seconds and between 7 and 10 by eight seconds. Google Maps would locate me in about 6-8 seconds.

Using "Get Position Test" the settings in the three lines above consistently gave the not only the fastest locks and the most locks - but, also STRONGER SIGNALS!

I used at least seven different combinations of the above settings and some of them were just as quick - but, not as strong. Most of them were slower.

If anyone has better information to add then please PM me and I will add it to this top post.

LASTLY, I will make some guesses as to what some of the other settings do as I have heard different information:

Application Settings:
Session Type: Tracking or Singleshot - obvious (use Tracking)
Start Mode: Hot or Cold Start - someone posted on a thread that Hot uses data from your last read to get started. Cold start will start all over. So, Cold start SHOULD increase the time for you to get a lock unless you went left the area to an area that had different satellite to look up.

Test Application:
Performance Test: worked for me - but, I found the test above to work faster and give me quicker results for what I wanted.
Hardware Test/Sensitivity Test: Pretty cool - went on forever and I stopped it.
CNO Test: Seemed to test the average satellite signal strength.
Antenna Test: Never worked for me and I received errors.
H/W Test Settings: Settings for the above tests - I didn't mess with them.

NOTE: WANT TO SEE HOW ACCURATE YOUR ACCELEROMETER/COMPASS/ORIENTATION settings are? Check this out:
Test Application/Show Sensor Data - there is no way to calibrate it here... But, you can see just how sensitive your instruments are!!


Delete GPS Data - I didn't select this button and I don't recommend anyone else doing so either unless someone from Samsung tells us what it does. LOL!

FINALLY: Keep in mind that if you are seeing GPS lock times that are in the 3-8 second range (which was what I was getting) this WILL NOT be how long it takes for Google Maps to get the GPS data! Expect 8-15 seconds or a little longer (but, under 30 seconds) for Google Maps to pick up your location. Although the GPS sensors might pick up the satellites - you still have to give the software time to evaluate the data and apply it to the software.


Hope this helps someone out there.

Update/Additional Information (http://androidforums.com/1194187-post197.html):
Hot Start - The GPS receiver remembers its last calculated position and which satellites were in view, the almanac used, and the UTC Time. It then performs a reset and attempts to acquire satellites and calculate a new position based upon the previous information. This is the quickest re-acquisition of a GPS lock.

Cold Start - The GPS receiver dumps all information and resets. It then attempts to locate satellites and then calculate a GPS lock. This takes the longest because there is no known information. The GPS receiver has to attempt to lock a satellite signal from all of the satellites, basically like polling, which takes a lot longer than knowing which satellites to look for. This re-acquisition of a GPS lock takes the longest.

Thanks to Shadow77895 for the link to this info. I altered the settings above. Doesn't effect my results much at all.
MSBased Operation Mode(http://www.vzwdevelopers.com/aims/public/menu/lbs/LBSFAQ.jsp#GenQues11):
What is MS-Based mode of operation?
In MS-Based mode, the network provides the satellite information to the device, based on a rough estimate of where the device is located, and the device acquires the GPS signals from the satellites and calculates its location. After the initial fix, the device operates like an autonomous GPS receiver, until the satellite information must be refreshed, at which time the device goes back to the network to update the satellite information. MS-Based mode is appropriate for applications that require the device location to be updated rapidly, such as a navigation application.

And email thread regarding using the Google settings for GPS(http://osdir.com/ml/android-platform/2009-08/msg00386.html)

NEW INFORMATION!!!

ALSO! Check out this page: http://www.pool.ntp.org/en/use.html:
As pool.ntp.org will assign you timeservers from all over the world, time quality will not be ideal. You get a bit better result if you use the continental zones (For example europe, north-america, oceania or asia.pool.ntp.org), and even better time if you use the country zone (like ch.pool.ntp.org in Switzerland) - for all these zones, you can again use the 0, 1 or 2 prefixes, like 0.ch.pool.ntp.org. Note, however, that the country zone might not exist for your country, or might contain only one or two timeservers. If you know timeservers that are really close to you (measured by network distance, with traceroute or ping), time probably will be even better.

Find your optimal pool server here: http://www.pool.ntp.org/zone/north-america
For US the optimal server is: us.pool.ntp.org

Reference other threads I (http://ip208-100-42-21.static.xda-developers.com/showthread.php?t=731462) I recommend you do the following:

Use Root Explorer or some other method (I use Root Explorer as it has a built in Text Editor and automatically backs up the altered file.) to go to here:
system/etc/gps.conf
Use the text editor to alter the gps.conf file to this (if you are in the US):

NTP_SERVER=us.pool.ntp.org
XTRA_SERVER_1=north-america.pool.ntp.org
XTRA_SERVER_2=http://xtra2.gpsonextra.net/xtra.bin
XTRA_SERVER_3=http://xtra3.gpsonextra.net/xtra.bin


If you are NOT in the US go to here: http://www.pool.ntp.org/en/use.html and look at the links in the center of the page to navigate to the closest pool to your geographical location and use that pool for the top server entry.

REQUEST FOR ADDITIONAL INFORMATION:
Many are suggesting that we do NOT leave the Secure Socket ON. How will this effect data security with our devices? I don't understand how it could hurt us... But, there must be a reason for it. If someone could let me know I would appreciate it.
 
Last edited:

systoxity

Senior Member
Nov 22, 2008
783
70
Good, guide, think you meant hot start should be faster though.

I'll be linking to this.

Sent from my Samsung Captivate using XDA app
 

haydonxda

Senior Member
Jul 20, 2010
253
48
Great, but doesn't address the problem

I need to point out that while this information is helpful it doesn't really address the problem that the GPS is facing.

What the above settings are doing is enabling multiple different A-GPS technologies to help compensate for the Galaxy S's poor GPS performance. A properly functioning GPS unit would not need these crutches except to acquire a faster fix.

I had my GPS outdoors today, with the first set of recommended settings, and was unable to achieve a fix while seven satellites were in view (according to it) with sufficient signal strength. This is a GPS firmware issue!

The above post is very helpful for people to get some better performance - however - the core GPS issues need to be addressed by Samsung.

I hope people will refrain from saying "It's perfect now!" and let up on Samsung. Unless you know what what the following are you're tweaking settings blindly and declaring victory: ephemeris, PDOP, SBAS, WGS-84, 2D fix, 3D fix (And the conditions one is chosen over the other.) and finally SA

I'm betting this phone would never achieve a fix in an SA environment! It's also clear that the person(s) who originated this information knew exactly what they were doing..!

If anyone is interested in learning how GPS works there are tons of great resources on the web that Google will point you to. Of course they're written for all sorts of different levels.

In short, the above settings may help, but please don't become convinced that things are "fixed"!
 

shaneaus

Senior Member
Nov 27, 2007
547
18
Austin, Texas
@haydonxda - I agree that this does NOT address the potential problem that the firmware and/or hardware is inadequate! And, we should put pressure on Samsung to fix this issue. However, the phones have already been produced and I'm just trying to do the best with I have.

@Shadow77895 - thanks for the info. Added a bunch of further information after looking into your posts and references from them.
 

andrewin

Senior Member
Nov 7, 2007
53
23
Try this fix (from 4pda.ru), working on Galaxy S, root access required:
$su
#cat /data/gps/secgps.conf > /sdcard/secgps.conf
#rm /data/gps/secgps.conf
#reboot

After reboot, new (correct) secgps.conf appears.

At your own risk!
 
Last edited:

rkorzuch

Senior Member
Jan 6, 2006
300
13
San, Diego, CA
NEW INFORMATION!!!

ALSO! Check out this page: http://www.pool.ntp.org/en/use.html:
As pool.ntp.org will assign you timeservers from all over the world, time quality will not be ideal. You get a bit better result if you use the continental zones (For example europe, north-america, oceania or asia.pool.ntp.org), and even better time if you use the country zone (like ch.pool.ntp.org in Switzerland) - for all these zones, you can again use the 0, 1 or 2 prefixes, like 0.ch.pool.ntp.org. Note, however, that the country zone might not exist for your country, or might contain only one or two timeservers. If you know timeservers that are really close to you (measured by network distance, with traceroute or ping), time probably will be even better.

Find your optimal pool server here: http://www.pool.ntp.org/zone/north-america
For US the optimal server is: us.pool.ntp.org

Reference other threads I (http://ip208-100-42-21.static.xda-developers.com/showthread.php?t=731462) I recommend you do the following:

Use Root Explorer or some other method (I use Root Explorer as it has a built in Text Editor and automatically backs up the altered file.) to go to here:
system/etc/gps.conf
Use the text editor to alter the gps.conf file to this (if you are in the US):

NTP_SERVER=us.pool.ntp.org
XTRA_SERVER_1=north-america.pool.ntp.org
XTRA_SERVER_2=http://xtra2.gpsonextra.net/xtra.bin
XTRA_SERVER_3=http://xtra3.gpsonextra.net/xtra.bin


If you are NOT in the US go to here: http://www.pool.ntp.org/en/use.html and look at the links in the center of the page to navigate to the closest pool to your geographical location and use that pool for the top server entry.

How do you use the text editor in Root Explorer. I can see the text but it won't allow me to edit it.
 

GAda

Member
Jun 30, 2010
47
0
Hello, the code:
*#*#1472365#*#*

starts a GPS Test Application.

The settings inside this application are only for this application.
You can test your GPS in different modes.

But the settings are not relevant for other applications.

It is a simple illusion that it helps to manipulate this settings.

GPS is very time-dependent.

And:
I don't know where we can change the default GPS Mode/s...
 
Last edited:

Main Target

Senior Member
Sep 20, 2008
254
15
So when I walk outside my office there are like 7 satellites, and I still cannot get a lock. This is sad.


Out of the box it worked great, navigated from BB to my house with relative ease. Inside my house when I showed my parents it worked great. I rooted and deleted some ATT apps. I have yet to get a lock.

I have also changed the NTP servers and no dice. This is pretty saddening performance.
 

uberamd

Senior Member
Jul 2, 2010
353
156
steve.blogme.us
I still don't get why my Nexus One, sitting right next to my Samsung Captivate, is able to get a aGPS location (via My Location in maps) that is pretty damn accurate despite not having a GPS lock and my Captivate is unable to even get an aGPS location and just says my location data is temporarily unavailable.

Nexus One: Can get approximate location very easily

Samsung Captivate: Cannot even get approximate location using WIFI/Cell Towers.

Foursquare never knows where I am until I go outside in the middle of a parking lot. This is BS.
 

hmose

Senior Member
Aug 5, 2009
75
0
New England
Won't anyone try GPS NMEA MONITOR App and see if the data sentences are correct? If the GPS chipset is putting out the correct Lat/Lon, then you can fiddle and fiddle what Captivate does with the information
 

Jreitnauer7

Member
Jul 8, 2010
36
0
Has anyone tried to contact Samsung about the issue yet? I tried yesterday and was on hold for an hour and half and then my call dropped. I'm joint to try again today.
 

TexUs

Senior Member
Jul 1, 2010
688
8
SkyHook isn't a "feature" persay, it's a corporation: http://www.skyhookwireless.com/

Same one Apple uses. Not sure exactly how it works but they do wardrive and use WiFi and triangulation to pick up your position as well, so leaving that OFF will perhaps be better for calibrating your GPS settings, but you certainly want it back ON when in normal use.
 

uberamd

Senior Member
Jul 2, 2010
353
156
steve.blogme.us
SkyHook isn't a "feature" persay, it's a corporation: http://www.skyhookwireless.com/

Same one Apple uses. Not sure exactly how it works but they do wardrive and use WiFi and triangulation to pick up your position as well, so leaving that OFF will perhaps be better for calibrating your GPS settings, but you certainly want it back ON when in normal use.

What kind of aGPS does the Nexus One use? I tried to dial the code and it didn't bring up the same menu on the Nexus (it may be different). My Nexus is great at figuring out where I am without a GPS signal.
 
May 6, 2010
46
13
I changed all my settings last night and it seemed to fix the issue. I was getting a lock within 10 seconds or less. Now I cannot get a lock with the exact same settings and reboot. Has anyone contacted Samsung over this? Anyone get an answer from them? I love this phone but the GPS issue sucks.
 
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ttu98ss

Member
Feb 13, 2009
12
0
Every time I try one of these new fixes it seems to work but then when I go somewher else it is broken again :( they need to fix this asap. I use that feature a lot
 

Jreitnauer7

Member
Jul 8, 2010
36
0
I changed all my settings last night and it seemed to fix the issue. I was getting a lock within 10 seconds or less. Now I cannot get a lock with the exact same settings and reboot. Has anyone contacted Samsung over this? Anyone get an answer from them? I love this phone but the GPS issue sucks.

I just got off the phone with Samsung galaxy s support. They knew nothing!!!!!! Said I was the first one to call with the issue.

I'm thinking about returning the phone... GPS is the most important part of a smartphone to me... I'm very disappointed
 

ttu98ss

Member
Feb 13, 2009
12
0
I just got off the phone with Samsung galaxy s support. They knew nothing!!!!!! Said I was the first one to call with the issue.

I'm thinking about returning the phone... GPS is the most important part of a smartphone to me... I'm very disappointed

I don't know about most important but I agree, it's very important. This HAS to be fixed
 

jhego

Senior Member
Nov 18, 2006
362
3
Los Angeles
I just got off the phone with Samsung galaxy s support. They knew nothing!!!!!! Said I was the first one to call with the issue.

I'm thinking about returning the phone... GPS is the most important part of a smartphone to me... I'm very disappointed

Don't give up hope, i'm sure that guy doesnt know anything. Engadget and a few sites are aware of the issue and i'm sure Samsung took notice. i'm sure a firmware fix is in the works.
 

JDM9499

Senior Member
Jul 22, 2010
165
31
Location

I have tried all the settings. And I don't really notice any difference. I live in the heart of Manhattan, NY., so I am sure roaming around int he concrete jungle trying to get a lock surely has a lot to do with my GPS issue. I do however, get a lock in every setting that has been written up in this forum, and other forums. The difference to me is hardly any, since it always takes many minutes for me to get a lock. I never have used any other GPS device since living here in the city, so I would like to ask other who live in a large city if it is taking them several minutes as well? Because it seems as though people are saying it is taking them only seconds to lock on. Hmmm.....
 

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  • 1
    I changed all my settings last night and it seemed to fix the issue. I was getting a lock within 10 seconds or less. Now I cannot get a lock with the exact same settings and reboot. Has anyone contacted Samsung over this? Anyone get an answer from them? I love this phone but the GPS issue sucks.
    1
    I facepalm every time someone complains they lose GPS satellite signal when they walk indoors...

    Dude, it BARELY works in my car with all my windows rolled down on a clear sky sunny day. If the windows are up, there is zero hope...

    Grabbing a signal from my back yard, then walking behind my all glass door (placing the phone up against the glass) visibly looses all signal on the GPStest app.
    1
    I greatly improved my GPS performance by doing this: First, a brief background: I was always curious about the two electrical contacts mating to the aluminum battery cover; if they were a ground plane or part of the antenna. For the heck of it I tried improving the connections by cleaning the small square contacts on the inside of the cover with a pencil eraser (they looked like they had a thin coating on them); and then gently, slightly prying up the contact on the right with a small screwdriver (the left is spring-loaded) and thats it. I was surprised to see an immediate improvement in signal strength resulting in locks within a minute and spot-on navigation. As a side note I noticed a better signal if I held the phone by it's sides vs cradled in my hand. It may be my imagination but I also seem to get a better signal (more bars) on the phone itself. I don't want to get anybody's hopes up, but this worked for me. Give it a try and let me know!
    1
    whoops..sorry about that: its *#3214789650#

    And it's pretty easy to remember the digits if you memorize it by the pattern of key presses. You start in the upper right and spiral around till you hit 5 and then jump to 0.
    1
    What Ever Happened to Ephemeris Downloads?

    I work with satellites and have some knowledge. When I had a WM6.5 phone, there was an option to dowload ephemeris. Ephemeris is updated satellite location data of the satellites. Even though satellites are in geosynchronous orbit (stationary orbits), they do tend wobble a bit (not perfect), enough to delay lock-on and have less accuracy. Therefore, the need for ephemeris.

    Is ephemeris downloaded automatically in the background unoticed in Adroid?

    TIA for any answers...