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Root Have you tried MS Based aGPS to help gps lock?

M

mantera

Android Expert
If you're still having GPS issues in an area where you have data coverage, and you've tried changing the gps.conf and possibly updating your libraries as noted in other threads, have you tried changing your GPS settings to MS Based instead of the default of "Standalone"?

From wikipedia:

Mobile Station Based (MSB) - In MSB mode A-GPS operation, the A-GPS device receives ephemeris, reference location, reference time and other optional assistance data from the A-GPS server. With the help of the above data, the A-GPS device receives signals from the visible satellites and calculates the position.

You can do that by doing the following, as noted in my previous post:

My GPS was really taking a long time to lock. Usually 10 minutes or so using GPS Status before it would lock. I tried both just using gps only and then also with wireless network and it still took a long time. So I updated the lbstestmode.apk to use MS Based and the gps.conf file that was mentioned earlier and now I get a lock in GPS Status in about 8 seconds from a cold boot using only the GPS with no wireless network.

If anyone wants to try, I've attached a flashable zip. I took the zip posted by merkuralex earlier in the other gps thread (thanks merkuralex) and added the lbstestmode.apk posted in this SDX thread:
http://forum.sdx-developers.com/index.php?topic=13593.0

The following flashable zips are attached:

lbstestmode_mt_gps_conf.zip - contains the gps.conf file from the other thread + the lbstestmode.apk file.

lbstestmode.zip - contains only the lbstestmode.apk

I'll repost the instructions here (thanks to cornaljoe on sdx for the actual instructions):

Pre-1. Flash the one of the attached zips in CWM first to install the lbstestmode.apk (or just copy the lbstestmode.apk into /system/app/ if you'd rather) and then reboot your phone.

Follow these directions:

1. After boot create a shortcut to Activities -> LbsTestMode -> .LbsTestMode
You may have to install LauncherPro if your launcher doesn't support the activities option under shortcuts. Once installed all launchers will have this option.

My note: Just an FYI, LauncherPro can be downloaded from the Market for free if you don't already have it. Or any other app that allows you to create shortcuts (such as AnyCut I think can also do that)


2. Start LbsTestMode and goto the application settings and set it to MS Based and press back until you exit app.

3. Reboot phone and then use GPS Status under a clear sky until you get a lock.
The main thing to pay attention to is the numbers labeled Error(m) and Fix/Sat in the lower corners of the compass.
Error(m) is the accuracy of your location in meters which shows after you get a lock. Fix/Sat is the number of satellites locked and in view prospectively.

In GPS Status, you can do the following to force aGPS data to download:
3A. Click Menu --> Tools --> Manage A-GPS state --> Reset . This will clear all previous A-GPS data.

3B. Click Menu --> Tools --> Manage A-GPS state --> Download. This will download fresh A-GPS data.

3C. Let GPS Status lock. The first time will take longer as your gps/phone syncs the data.

After you get a lock, you can try powering down your phone and then restarting and see if your lock is faster from a cold start.

This may or may not help you. All I can say is that changing to MS Based helped my gps lock time--I usually have data access where I am.
 

Attachments

trying now... will report back if it worked for me :D (knowing that its different for everyone)

EDIT: ok i tried it and it worked perfectly!!! also the guide was very easy to use! :D
 
I told 'ya the stock GPS setup wasn't using the assist data..... ;-) (I've been tracing this bitch now for more than two weeks...)
 
tickerguy said:
I told 'ya the stock GPS setup wasn't using the assist data..... ;-) (I've been tracing this bitch now for more than two weeks...)
Click to expand...

It may not be. But it must be doing something because if I set my gps back to Standalone, I take a much longer time to get a gps lock than when I have it set to MS Based. So that's all I can go on. So even if it's not doing what it's supposed to be doing, it seems to be helping.
 
That was my point - the stock build never requests AGPS data. It's got all the debugging turned on and it's clearly not asking for it... it's running in "standalone" mode.
 
I understand what you're saying. Can you explain why changing the settings to MS Based would decrease the gps lock time then?

Oh and btw, the default setting in the stock build is set to "standalone". So it should not be requesting aGPS data by default.
 
Yes. The stock build doesn't appear to use AGPS at all. It therefore relies on the internally-stored ephermis and almanac, and that data becomes stale rather quickly. My CM7 build tries to refresh this and fails (and I believe it destroys the old data at the same time, which is a real problem as it likely leaves BAD data in the system, preventing the lock from working at all. This is almost-certainly why CM7 currently cannot get a lock, and unfortunately fixing that is a problem.)

If you turn on assisted mode in theory it should go grab the aGPS data and that results in very fast lock times as the system now knows where the satellites are. You need three things to get a satellite lock - the ephermis, the almanac and a precision timestamp. The first two can come from the satellites themselves but a full load from the satellites takes upwards of 12 minutes, because the bitrate from the satellite is extremely low. The time, if available, allows using the other two to calculate exactly where the birds should be.

What you're reporting is what I would expect from a successful setting of the AGPS mode (which was not previously being set.)
 
JollyRoger87 said:
Fresh boot, fired up navigation outside and locked on in 2.5 seconds literally!

Indoors locks at 9 seconds wow!
Click to expand...
Ditto... thanks a lot for this mantera. The GPS locks instantly now. I had previously updated the libraries and modified the gps.conf file. The lock was quicker than before the tweaks, but now it's instantaneous, even indoors.
 
want this gps fix badly...so i:

installed CWM
copied lbstestmode_mt_gps_conf.zip to sd card
installed it with cwm and rebooted

but when i go to make shortcut its not listed under activities anywhere. can't figure out which part i'm missing... the apk is there in the system/apps folder but i cant run it directly. since no one else seems to be having this problem... must be something i'm doing... any help would be greatly appreciated

i'm rooted running stock
 
Hey I have a dumb question. In step number 3 it says to use "GPS Status". Is "GPS Status a different app? Is it Lbs Test Mode? Once I figure out how to get past that step I will be in the clear. Thanks in advance.

EDIT: Ok it was another app that I downloaded from the market.

EDIT 2: THANKS!! This helped my gps get a lock much quicker!
 
For some reason when I try to change it to Ms based who's it never sticks. I exit the app and open it back up and it still shows stabdalone! I'm rooted anyone got any ideas?
 
H'm that is weird I may flash back to stock and see f mine sticks. But also the secret code to get to the lbstest mode don't work on mine either. The code is *#*#1472365#*#* put that in the dialer and see if anything comes up. Nothing happens on mine!
 
b_randon14 said:
H'm that is weird I may flash back to stock and see f mine sticks. But also the secret code to get to the lbstest mode don't work on mine either. The code is *#*#1472365#*#* put that in the dialer and see if anything comes up. Nothing happens on mine!
Click to expand...

hey brandon... i flashed the zip that gives you the gps.conf and the lbstest mode app. then i used anycut to make the shortcut and changed what i needed and it stayed after reboot.
 
Yeah it still wouldnt work with any cut. I installed that zip and it didnt work. I have got something all messed up on my phone somewhere. I'm restoring back to stock to see how it goes!
 
Okay so I flashed back to my stock Deodexed ROM and it worked fine. So somewhere along the way I messed something up lol now I just got to track it down!!
 
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