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GPS-long fix times and accuracy issues.

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Visitor
Message 1 of 36
16,746 Views
Message 1 of 36

GPS-long fix times and accuracy issues.

I have noticed that the GPS in xperia u to be very slow. fix times are too long and position is less accurate. I tried to compare it with my bro 's LG optimus One(p500). We both stood at the same position and started our GPS and then Google maps app. To begin with it xperia u showed an accuracy of 2900 m where as optimus One showed a better (not much but stil.. ) 2500 m. And within 30 seconds his accuracy came to 7 m and my xperia u is still struggling with 2500 m. It Took around 4 minutes to show an accuracy of 50 m.

How come xperia's GPS be so dumb against a cheap phone.

Is this only me or is it the same case with every xperia u.

How can Sony make these terrible GPSs ? Optimus One is inferior in all the specs but is much better travel companion came very handy in our last trip.

Message title was edited by: pradeeprk4

1 ACCEPTED SOLUTION

Accepted Solutions
Visitor
Message 30 of 36
7,698 Views
Message 30 of 36

Re: GPS-long fix times and accuracy issues.

I finally found the flaw, that I had all this time.

I rooted my phone and messes up with the gps.conf and tried many modifications to make it work.

Finally found that it is the problem with the AGPS SUPL server.

it is the server that is contacted by phone to get agps data. If that data is downloaded and there is some GPS signal, gps will fix instantly.

Somehow, that server was changed to

SUPL_HOST=supl.google.com

SUPL_PORT=7276

instead of

SUPL_HOST=supl.sonyericsson.com

SUPL_PORT=7275

This caused problems fetting agps data, and only gps was used to fix, which would usually take 12-15 mins.

One more thing that effects the time of fix is the ntp server. Change it to your own country and the gps will fix within 15-30 secs, even on cold start.

There is an app to modify this file easily, if you are feared of messing up with the file.

FasterGPS.

(agps server setting is located in advanced settings).

To sum up, if you have set up NTP server to your country, and agps server to sonyericsson and have working internet connection(only for downloading AGPS which is negligible in amount), there should be no problem with gps fixes.

(I PMed Oscar-GPS to know about AGPS server details, credits to him)

After applying these settings, I'm now getting fixes within half a minute and accuracy of 4-8m, consistently, and it connects upto 10 satellites,.

Screenshot_2013-06-14-07-02-30.png

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35 REPLIES 35
Visitor
Message 2 of 36
6,808 Views
Message 2 of 36

Re: terrible GPS compared to optimus p500

One of the reasons I bought xperia u is for using google maps along with GPS. I have not used it extensively but some of my observations are :

1) Since it is aGPS initially the location is decided by using signal strength from cell towers. So in xperia u or any phone its is dependent on how many cell towers are in vicinity and whether the service provider has correctly programmed the tower latitude longitude or not.

I found in xperia u this feature of location(without GPS) inferior to my Sony Ericsson Naite ! But I am still comparing it. So initial location of within 2.5 km or so is ok. But it should locate you on the street if you are moving in car or bus:smileyinfo:, So this is about when either GPS was not on OR just as you start google Maps with GPS on !

2) When I start GMaps with GPS on, it is taking about a minute if i am moving in car or bus. So that satellite signal is good.  In stationary condition inside house it takes 3 minutes. But as we know it all depends on sat signals. However XU's GPS location appears to be slow !

Visitor
Message 3 of 36
6,808 Views
Message 3 of 36

Re: terrible GPS compared to optimus p500

Even when moving in car my gps seems to be slower. I'm sure that fixing time nowhere near One minute. Even when I'm in completely open area or moving in car it's taking 3-4 minutes of time to fix GPS.

Visitor
Message 4 of 36
6,808 Views
Message 4 of 36

Re: terrible GPS compared to optimus p500

Thats not good ! Maybe Sony experts should comment on this

Visitor
Message 5 of 36
6,808 Views
Message 5 of 36

Re: terrible GPS compared to optimus p500

is your gps fast?

Visitor
Message 6 of 36
6,808 Views
Message 6 of 36

Re: terrible GPS compared to optimus p500

it is ok in some situations. like i got fix (accuracy improved from 2.5 km to 8 metres within 30 seconds while moving in bus yesterday.

Visitor
Message 7 of 36
6,808 Views
Message 7 of 36

Re: terrible GPS compared to optimus p500

I don't understant, no body from support replied on thread but it is marked as answered..

How can it be??

Visitor
Message 8 of 36
6,808 Views
Message 8 of 36

Re: terrible GPS compared to optimus p500

Sorry guys!

For me, the GPS works fine. I'm in india. Xperia U took 14 seconds to find my location with a 6M accuracy but iPhone 4S took 20 seconds.

I think the time taken may be depends upon the Data connection speed.

I checked Xperia U while i travelled in a car at a speed around 60 KMPH. It followed my location by 8 seconds lag. But i ckecked this with a 2G GPRS Connection.

While at 3G coverage area it worked with a 5 Second lag.

My reply may be inappropriate...

Visitor
Message 9 of 36
6,808 Views
Message 9 of 36

Re: terrible GPS compared to optimus p500

contacted xperia u  support via phone.

they know nothing.. I guess they never used or even know GPS.

after each of my sentence he puts the call on hold "to check the info"..

first guy disconnected the call after 20 min, and I called again.

He told me a mindblowing thing... GPS takes 15 to 40 mins of time to show the location....LOLAnguished Face

he is not convinced that it's wrong even after another 15 mins of discussion.

And when I ask him about accuracy he answers thet it doesn't show exact position.. I know that but no gps shows an accuracy of 2km right?

and even for simple questions he says he doesn't have the info..

I couldn't do anything but getting angry and frustated.

Where does get all these dumb guys for tech support?

I had a lot of respect for SONY before buying this phone but I'm really starting to hate it.Angry Face

It seems that only option I have is to repair OS, I can only hope that works.

Unregistered user
Not applicable
Message 10 of 36
6,808 Views
Message 10 of 36

Re: terrible GPS compared to optimus p500

I have the same exact problem. To me it seems some kind of software problem involving A-GPS. Even if it is just an impression, it seems that not using A-GPS surprsingly gives better results. My phone is a branded one, it has some presonalizations of Italian operator TIM, so maybe it could be some problem related to that.

I am strongly hoping to find a solution, maybe with Andorid 4 things will be better. Unfortunately if I do not find a solution to the issue i will resell my phone, since, as it is, the GPS is completely useless. It is not reasonable to wait 5 minutes before a fix to have any clue about what direction to take.