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Hi
Does aGPS require you to have a cellular data connection in order for it to work? Or will it work with any internet connection (eg. using my laptop's connection through wifi)? I'm asking because I don't have a data plan (yet), and my phone has locked only _once_ since I bought it a month or so ago. I've tried switching to MS based in LbsTestmode, changing the supl server to supl-google-com and supl-nokia-com (can't post links yet).
The one time it did lock was when I was testing the GPS without an internet connection, and I entered a WiFi covered area and it suddenly locked (5-10m accuracy). It wasn't WiFi-based positioning because it was my laptop's WiFi hotspot. And I was using the default settings at that time (www-spirent-lcs-com, Standalone mode). Since then I've tried different combinations of settings but it hasn't ever locked.
Another question: What's the difference between MS based and MS assisted modes?
My phone is an I9000 Galaxy S.
ssj4Gogeta1 said:
Hi
Does aGPS require you to have a cellular data connection in order for it to work? Or will it work with any internet connection (eg. using my laptop's connection through wifi)? I'm asking because I don't have a data plan (yet), and my phone has locked only _once_ since I bought it a month or so ago. I've tried switching to MS based in LbsTestmode, changing the supl server to supl-google-com and supl-nokia-com (can't post links yet).
The one time it did lock was when I was testing the GPS without an internet connection, and I entered a WiFi covered area and it suddenly locked (5-10m accuracy). It wasn't WiFi-based positioning because it was my laptop's WiFi hotspot. And I was using the default settings at that time (www-spirent-lcs-com, Standalone mode). Since then I've tried different combinations of settings but it hasn't ever locked.
Another question: What's the difference between MS based and MS assisted modes?
My phone is an I9000 Galaxy S.
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Correct me if i am wrong, but as i know aGPS doesn´t need any Data Connection to make the triangulation between the GSM Antennas. So no need for Internet Connection to use aGPS.
TMReuffurth said:
Correct me if i am wrong, but as i know aGPS doesn´t need any Data Connection to make the triangulation between the GSM Antennas. So no need for Internet Connection to use aGPS.
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AFAIK aGPS is different from cellular triangulation. It refers to downloading satellite information from a server for a quicker fix.
ssj4Gogeta1 said:
AFAIK aGPS is different from cellular triangulation. It refers to downloading satellite information from a server for a quicker fix.
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I thought it would make a triangulation between the next availabe antennas in range and get over a dedicated channel (not data channel as mentioned above) localisation informations. Because my Nokia N80 had aGPS but not real GPS and in the manual they said something about this triangulation.
But of course i know the download of the actual satelite coordenates from my Touch HD in Windows Mobile with a dedicated App. Just thougth it is something diferent.
TMReuffurth said:
I thought it would make a triangulation between the next availabe antennas in range and get over a dedicated channel (not data channel as mentioned above) localisation informations. Because my Nokia N80 had aGPS but not real GPS and in the manual they said something about this triangulation.
But of course i know the download of the actual satelite coordenates from my Touch HD in Windows Mobile with a dedicated App. Just thougth it is something diferent.
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aGPS is a technology that downloads satellite data from agps servers at realtime (that is the time you are using the GPS): WIKI article
I guess that the app you are refering to, the one you used on the HTC, is Quick GPS. This program doesn't download satellite postition data in realtime but once in a while. (I believe the data are vallid for 48h) With Quick GPS one can still enjoy the features of aGPS while one hasn't a data connection with a aGPS server.
The Galaxy S GPS (BCM4751) seems to have both, aGPS and a sort of Quick GPS. Only the last is called LTO by broadcom. (see: http://www.broadcom.com/press/release.php?id=s443754 about BCM4571 specs and see here about LTO.
aGPS uses cell tower triangulation, and information from a server, in addition to satellite radio signals, to quickly assist in determining the coordinates of a phone's location. Since cell tower sites are precisely surveyed, they are a reliable source for locational data. A data connection is required. All modern cell phones, at least here in the United States, are required to have aGPS service for use in locating a phone by emergency responders. This is a part of the E911 and is required by FCC mandate. Data is used in tracking down the phone, but it happens behind the scenes and is paid for by fees charged to cellular users on their bills for E911 compliance.
On phones that allow the user to make use of the aGPS chip, there will generally be a setting that allows you to set for E911 use only, or for what is commonly referred to as "location based services." On my Android phones, there are actually two settings, both found in Location & Security Settings. One allows for location based upon use of wireless networks, and the other allowing a fix via GPS satellites. Even with any location based services turned off, emergency responders can still find the phone. The difference being that you cannot use it.
While it is technically possible for you to use your phone's aGPS without a data connection, your chances of getting a signal are sketchy, and your chances of getting a really accurate signal are, under most circumstances, slim to none. Much of the computational work in determining your location is done by the assistance server, and guess how that information moves to and from your phone? Yep, you guessed it, data!
GPS signals sent from satellites are simply radio signals, and your local pop music radio station probably sends its signals with more force. As they are radio signals, they have to contend with everything a radio signal has to deal with, and a large percentage of that is man-made. Signals confusingly bounce off of buildings, are weakened by passing through walls and foliage, or can even be absorbed in some cases by different materials.
Some aGPS chips cannot function as stand alone GPS, and will not work at all without a data connection.
Try this, turn off your cellular radio. Make sure that your WiFi is also off. Now, fire up Google Maps and ask it to start navigation. How did it work?
appelflap said:
I guess that the app you are refering to, the one you used on the HTC, is Quick GPS. This program doesn't download satellite postition data in realtime but once in a while. (I believe the data are vallid for 48h) With Quick GPS one can still enjoy the features of aGPS while one hasn't a data connection with a aGPS server.
.
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Yeah, that i was talking about. Didn´t know this all I love this forum, you always learn more and more.
rasmith3530 said:
Try this, turn off your cellular radio. Make sure that your WiFi is also off. Now, fire up Google Maps and ask it to start navigation. How did it work?
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Well, using Google Maps would not be a valid test, of course, since you need data connection to download the local map anyway. If you want to test whether data connection is requires by aGPS, you need to use an offline GPS application.
Thank you for your guys replies.
@rasmith3530: So can that data be downloaded over wifi? (My common sense says yes, just trying to confirm.) If it can, then aGPS isn't working for me at all. I see at max 2-3 satellites in LbsTestMode, without a lock on any of them.
No one said aGPS is working on SGS. They are broken and no fixes yet.
foxbat121 said:
No one said aGPS is working on SGS. They are broken and no fixes yet.
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I think you're right. The fact that there are no ephemeris and almanac data recorded for satellites let me think that it may be the case that with a certain informed guess aGPS and the advertised LTO function doesn't work on none of the firmwares.
Other people seem to have locking/accuracy problems, they can at least see those satellites. Mine normally shows 0 or 1, so I thought maybe I'm doing something wrong.
ssj4Gogeta1 said:
Other people seem to have locking/accuracy problems, they can at least see those satellites. Mine normally shows 0 or 1, so I thought maybe I'm doing something wrong.
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In JM1-JG5, I had that issue (couldn't lock onto anything). Switching to JM5 fixed that..
Hey guys no one has had problems with the GPS fix?
Thanks
Nope, it's working great.
Why? Do you have a problem with it?
i tested the GPS as soon as i got it. caught my position within 15 seconds to 10 metres from its first ever try.
jusba64 said:
Hey guys no one has had problems with the GPS fix?
Thanks
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don't forget to turn on your data connection at all times when using gps (locations or maps) because otherwise, you will not get a gps fix
despite HTC's thourough promotion of the Locations app with "preloaded maps", you still need a data connection to use the locations program. Utterly ridicoulous but heck, what can you do...
matthiasdeblaiser said:
don't forget to turn on your data connection at all times when using gps (locations or maps) because otherwise, you will not get a gps fix
despite HTC's thourough promotion of the Locations app with "preloaded maps", you still need a data connection to use the locations program. Utterly ridicoulous but heck, what can you do...
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It's not impossible to use Locations without data, it will just take longer to get a GPS fix.
matthiasdeblaiser said:
don't forget to turn on your data connection at all times when using gps (locations or maps) because otherwise, you will not get a gps fix
despite HTC's thourough promotion of the Locations app with "preloaded maps", you still need a data connection to use the locations program. Utterly ridicoulous but heck, what can you do...
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I'll have to disagree. I only need data connection to get the AGPS data which speeds up fix. After that the Locations app works fine, even with data turned off. Have you downloaded maps to your SD card?
Well...
I am not sure if I i have a problem, but this is my situation:
Both me and my girlfriend own a DHD.
I have installed copilot on both devices and when I turn on copilot and turn on gps (but have data connection disabled), her GPS fix takes about 30 seconders - 2 minutes, and mine may take > 15 minutes.
Surely 15 minutes should not be acceptable, even with data turned of ,right??
paulus_01 said:
Well...
I am not sure if I i have a problem, but this is my situation:
Both me and my girlfriend own a DHD.
I have installed copilot on both devices and when I turn on copilot and turn on gps (but have data connection disabled), her GPS fix takes about 30 seconders - 2 minutes, and mine may take > 15 minutes.
Surely 15 minutes should not be acceptable, even with data turned of ,right??
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Try downloading Gps Status from the market. Use it to reset your AGPS data and download new one. See if it makes any difference.
olivierlee said:
Try downloading Gps Status from the market. Use it to reset your AGPS data and download new one. See if it makes any difference.
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Thx, will have a look when I am at home and let you know if it helped.
It can improve the GPS fix, even if I do not turn on the data connection thereafter?
i had a problem with the lock. i went to the market place and got a normal gps satelite info applcaition. i then waitied for about 20 minutes for it to get a fix(first time) when i then opened HTC locations it worked properly and gets a fix really fast. i guess its just the first time.
SO if you are not getting a fix, WAIT a while for the first time maybe even 30 mins and then it will be fine.
BTW, my GPS fix issue has now been solved....do not know why, but at least it fixes within 1-2 mins or so...
Sometimes it's all about waiting. GPS locating can be very dodgy since it depends on too many factors and is initially a veeeery old technology.
I heard that soon tho EU will launch their own positioning sistem (Galileo - worth 3.4 billion;] ) that's accurate to the meter and since in some way will cooperate with NAVSTAR ( the US current GPS ) will hopefully have better "reception".
Until then - we wait and rely on bloody AGPS
Question in title.. the other day, I went to the mountains and did not have any signal but my gps worked just fine. This leads the question, does using the gps use any mobile data at all?
I'd guess no, but I'd be more curious to see if an app like GPS Essentials works when you're in that situation. It pulls a lot of info from GPS.
There is an app that caches a large map file on your SD card so you can do basic map (not google) navigation without any data connection at all but the name of it escapes me at the moment. If that app is even possible then I'd guess GPS can function independently of data as long as it doesn't need anything beyond basic location info.
Today's Google Maps update in the market kinda deals with this. It adds caching options so that if you lose your data connection (which is required for things like driving navigation) you don't lose everything else too. It caches data so the phone can continue working for a few minutes even without a data signal.
The GPS has a function which access the internet to help it lock on for the first time. It looks up on the internet where the satellites might be. If you have a standalone GPS that you have not used for a while, it takes several minutes to lock on. Looking up where the satellites are on the sky through the internet speeds this up significantly. I believe that is what is called A-GPS. But I believe any GPS works standalone, without data.
forum.xda-developers.com/showthread.php?t=819394
YES .......
I have an easy question about GPS, I am using Vibrant without network plan. So I don't know if I can use GPS with out any wifi or 3g? I am using the BV 1.3.1 now.. If that will work, how can I set up?
GPS uses military run satellites to determine you location. The network or data transfer is irreverent. Your GPS will work without network connection.
Now lets say you try to navigate to a location with Google maps. This will not work, although the phone will know your location it can not use the network to DL the maps nor calculate your route. If you use a nav app that store a maps on your SD card, then you'll be fine
SykesAT said:
GPS uses military run satellites to determine you location. The network or data transfer is irreverent. Your GPS will work without network connection.
Now lets say you try to navigate to a location with Google maps. This will not work, although the phone will know your location it can not use the network to DL the maps nor calculate your route. If you use a nav app that store a maps on your SD card, then you'll be fine
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+1 yup plus it will be slower
oka1 said:
+1 yup plus it will be slower
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It will be slower? The GPS navigate will be slower or the phone will be slower? much slower?
oka1 said:
+1 yup plus it will be slower
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Is there any nav app that we can't download free and store the maps in SD so that can navigate without network?
oka1 said:
+1 yup plus it will be slower
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pxc668 said:
It will be slower? The GPS navigate will be slower or the phone will be slower? much slower?
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I don't see how the phone would be slower, in any regard. It would not affect the phones processing speed, nor would the gps run slower. The only thing that could be slower is finding your location from a cold start, using network location can speed this, but imo it's irrelevant. Network location is too inaccurate for navigation.
There are some apps which store maps, but none that are free. Maybe someone else knows of one.
In my experience, GPS lock can be considerably slower without the network. The AGPS works by querying the network to get supplemental information like precise time and maybe ephemeris data (precise sat location) which can make a huge difference in acquiring lock. The phone is capable of acquiring lock without this network aid, but locks can take minutes, and accurate locks can take many minutes.
Of course, the other caveats about requiring off-line maps etc for navigation functions also apply.
I don't have a data plan either but my gps works just fine. It locks onto sats in about 10 sec.
http://forum.xda-developers.com/showthread.php?p=10488647
thats open source map app where u can drop locations to go turn by turn (initially the maps load over wifi, but u can choose to save them and save them according to the resolution. I live in Atlanta so i only saved the GA portion with a decent resolution, which is nice that i dont have to worry about downloading states ill never need).
i personally use copilot live more (about 1gb for USA maps with poi)
i forgot the price, but it is 100% worth it (almost better than my in car navi)
Running bionix btw if that helps with gps lockon timings
and dont forget to get apn droid from the app store to make sure it disables all cellular network data. only downside is that if you want mms then u have to turn it back on reboot and then download the mms then turn it off again, but i dont get many mms anyway so its ok.
Get CoPilot Live USA.
Its $5 on the market and it preloads the maps for the country on your phone. Works WITHOUT data and the interface is SLICK. Full 3D navigation with really good voice turn by turn.
One of the best purchases I ever made. Hope it helps you too
PS: Maps get updated about every month so they are always current as far as road names and points of interest. Note that since it isn't using any data and data triangulation, if it is the first time you use it after a phone reboot it will take up to 3-4 minutes to lock on. This is normal as it is the same if you try any 3rd party GPS receiver navigation system. Once you've used it once since the phone has booted up, lockon time will be under a minute.
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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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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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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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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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.
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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
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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 ?
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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.
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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
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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.