The other day the GPS had the weirdest issue. I was stuck in traffic and decided to turn on Google Maps to find out how long the traffic is going to be. To my disbelief, the GPS showed me in a different town and MOVING on the street and then onto some freeway about 50 miles from my location. I thought the GPS satellites are screwed up but my car was showing me in the right place (and never has made such a stupid error).
Makes me wonder if the GPS info is actually going to Google servers and coming back to the phone as I guess I was getting someone else's GPS data and the lines were crossed somehow. This continued to about 30 minutes as I was enjoying the error and wondering at the same time. Holding the phone out of the window and stuff did not work. Eventually I reboot (oops! I meant I took the battery out because HTC apparently thinks we never need to reboot te G1 so there is no PIN hole for reboot like most other phones).
has anyone else experienced the same issue?
brooklynite said:
The other day the GPS had the weirdest issue. I was stuck in traffic and decided to turn on Google Maps to find out how long the traffic is going to be. To my disbelief, the GPS showed me in a different town and MOVING on the street and then onto some freeway about 50 miles from my location. I thought the GPS satellites are screwed up but my car was showing me in the right place (and never has made such a stupid error).
Makes me wonder if the GPS info is actually going to Google servers and coming back to the phone as I guess I was getting someone else's GPS data and the lines were crossed somehow. This continued to about 30 minutes as I was enjoying the error and wondering at the same time. Holding the phone out of the window and stuff did not work. Eventually I reboot (oops! I meant I took the battery out because HTC apparently thinks we never need to reboot te G1 so there is no PIN hole for reboot like most other phones).
has anyone else experienced the same issue?
Click to expand...
Click to collapse
The GPS is not being relayed to google... but google maps may be the thing that is wrong here. You can't get your "lines crossed" when using google maps but the maps may be downloading the wrong set. I know I have seen it do some weird things but that is expected to happen when you have several countries you have to have maps for.
As for the reboot issue... is it really that hard to hold down the power button? You do realize that the pin hole on previous devices is for emergencies only. It could really screw up the phone. Similarly like using your computer and unpluging it while it is on... or just pressing its reset button.
Maybe this is the reason for your problems with your G1.
I was just browsing my location and found that the location was in my local Radio Shack that was 2 blocks away. I tried to refresh but wouldn't allow me to.
G1 uses assisted GPS, which performs some calculations away from your phone. Could have been your A-GPS server was sending back some faulty data.
Some Application in G1 read Location info from Proprietary GPS Chip and also relies on Cell Tower GPS Coordination if GPS Signals is not available, in India my Airtel Company have Bad GPS Coordination in my Cell Tower, I Personally know which Cell Tower i am hooked to while i am at home but the Cell GPS Coordination is 8 Miles away from my Cell Tower.
Check that your GPS Signal were Strong and you have not just started seeing maps when that error occured.
I think it was stong. I had all my bars full and the 3g logo on it. Oh well I'll probably fiddle with it a little more tomorrow after I try to get a screen protector for the phone
I thought the problem had gone away until last night it happened again, with one difference. I still had me being shown 20-30 miles away (interestingly not across the globe but simply 30 miles away) the problem corrected itself after about 5 minutes.
I have a car GPS and a portable GPS and I have never seen this happen before. The issue is definately the A-GPS. I always thought during WAR the military may scramble the GPS data to confuse the enemy, I guess that is what promted Europeans to install their own GPS that is much more accurate than ours.
And there are controversies over this as well. Google is recording my location and my cell towers and IP addresses and URLs according to its NO privacy policy. This is definitely not fun.
Sending my GPS info to Google servers (which is in fact the case) without me knowing it and sending it back to my phone through internet channels it not something I am comfortable with. Especially if Google releases information to law enforcement one day that may be incorrect showing me somewhere I really was not at!
CORRECTION: A-GPS is for phones without GPS. It does not apply to this thread.
brooklynite said:
CORRECTION: A-GPS is for phones without GPS. It does not apply to this thread.
Click to expand...
Click to collapse
Where do you get your information? aGPS is for phones with GPS... it uses a data connection to locate you within so many meters than uses the GPS signal to pinpoint so you are located faster.
brooklynite said:
CORRECTION: A-GPS is for phones without GPS. It does not apply to this thread.
Click to expand...
Click to collapse
Wrong.
http://en.wikipedia.org/wiki/GPS_Phone
http://www.apple.com/iphone/features/gps.html
I have the same dxmn problem with the gps f-ing up. It started with RC30...When I was on RC19...I had NO PROBLEMS with gps.
It would pinpoint my location in 5sec. Now it's take 10-15min to pinpoint me. Google need to fix this fast.
whether it is related to this thread or not...A-GPS....
, generally abbreviated as A-GPS, enhances the startup performance of a GPS satellite-based positioning system. It is used extensively with GPS-capable cellular phones
Click to expand...
Click to collapse
same problem here. i also think it started with the update.
Guys, I am not wrong.
A-GPS as Google calls it (and there are other versions of it), is for phones without a GPS chip (thats how Google Maps find you on a T-Mobile WING), it started after an fcc mandate to be able to locate 911 callers from cell phone. It finds your location using a triangulation of the cell towers you are connected to and this particular technology and the extensive data that is required is owned by Google however Google may not call it AGPS.
http://www.techcrunch.com/2007/11/28/google-mobile-maps-pinpoints-your-location-without-gps/
Now it seems to me that Google is enhancing its data network of cell towers using our phones to collect location data. So it collects the cell towers we are connected to with the strength+ the GPS info from our phones and puts all this data in a server to that non-GPS phones using Google Maps can have a better triangulation as more data is gathered from across the country. Eventually the system could be perfected to locate any cell phone without a GPS chip or to locate a cellphone with the GPS feature turned off for privacy, and that is what concerns me.
When my phone shows me 20 miles from where I am, on the freeway, cruising at 55MPH while I am sitting in traffic on the other side of town, it concerns me.
brooklynite said:
Guys, I am not wrong.
A-GPS as Google calls it (and there are other versions of it), is for phones without a GPS chip (thats how Google Maps find you on a T-Mobile WING), it started after an fcc mandate to be able to locate 911 callers from cell phone. It finds your location using a triangulation of the cell towers you are connected to and this particular technology and the extensive data that is required is owned by Google however Google may not call it AGPS.
http://www.techcrunch.com/2007/11/28/google-mobile-maps-pinpoints-your-location-without-gps/
Now it seems to me that Google is enhancing its data network of cell towers using our phones to collect location data. So it collects the cell towers we are connected to with the strength+ the GPS info from our phones and puts all this data in a server to that non-GPS phones using Google Maps can have a better triangulation as more data is gathered from across the country. Eventually the system could be perfected to locate any cell phone without a GPS chip or to locate a cellphone with the GPS feature turned off for privacy, and that is what concerns me.
When my phone shows me 20 miles from where I am, on the freeway, cruising at 55MPH while I am sitting in traffic on the other side of town, it concerns me.
Click to expand...
Click to collapse
Where are you getting your information? The link you provide just says they support phones without GPS but they never say it is only for phones without GPS. In fact it says that it will work on phones with GPS... that is what the whole article is about that phones in the future will have GPS and google maps will be able to pinpoint their location faster. Basically it says they are using A-GPS.
In the link above he links to http://www.techcrunch.com/2007/11/28/google-earth-heading-towards-extinction/ Which says people will be able to add their own commentary about places like a wiki. Nothing about using other peoples devices to send information for google to collect.
It also has this link http://www.google.com/intl/en/press/annc/20071128_maps_mobile_my_location.html Which is googles official press link saying it will work with both GPS and non-GPS phones by using the Cell ID and a special formula that google developed to pinpoint your location within a certain amount of distance. Nothing says it uses other peoples GPS signals. In fact it says "This approximation is anonymous, as Google does not gather any personally identifiable information or associate any location data with personally identifiable information as part of the My Location feature."
All in all I think you are misreading and need to look over your data again.
neoobs said:
Where are you getting your information? The link you provide just says they support phones without GPS but they never say it is only for phones without GPS. In fact it says that it will work on phones with GPS... that is what the whole article is about that phones in the future will have GPS and google maps will be able to pinpoint their location faster. Basically it says they are using A-GPS.
In the link above he links to http://www.techcrunch.com/2007/11/28/google-earth-heading-towards-extinction/ Which says people will be able to add their own commentary about places like a wiki. Nothing about using other peoples devices to send information for google to collect.
It also has this link http://www.google.com/intl/en/press/annc/20071128_maps_mobile_my_location.html Which is googles official press link saying it will work with both GPS and non-GPS phones by using the Cell ID and a special formula that google developed to pinpoint your location within a certain amount of distance. Nothing says it uses other peoples GPS signals. In fact it says "This approximation is anonymous, as Google does not gather any personally identifiable information or associate any location data with personally identifiable information as part of the My Location feature."
All in all I think you are misreading and need to look over your data again.
Click to expand...
Click to collapse
Regardless of above, and you may be correct and I may be wrong, but the thread is getting distracted from the main subject. My main issue is this: Why is the GPS reporting me in the wrong location, and even MOVING which is weird. It was pretty obvious to me from what I saw that the Google Maps software in my phone was reading someone else's location data from someone else's GPS. I could see the person move through the streets and speed up and slow down. This makes me wonder if my locatio data is being sent to Google servers somewhere and then back to the phone (and in some cases crossed over with another persons data). This feels especially more true because Google MAPS has slowed down dramatically from finding "My Location" compared to "pre RC30" upgrade and even compared to the GPS-Chop-Free WING and even my ancient car's GPS system.
Have you talked to Google about this? I think you are just speculating what you want and have a hidden agenda. Did it locate you within so many feet? or was it a real location? If it was a real location than it couldn't be Google as it only pulls the map the actual lat, long is coming straight from the sats... possibly it pulled the wrong location for that tower while using A-GPS and then this calculated the wrong GPS coordinates.
Since you don't know what or how A-GPS works this may be hard to understand. A-GPS works by using that method you described for non-GPS cellphones to narrow the search for satalites. This doesn't find your location it only finds the vicinity. You can see the A part of A-GPS work when it says your location within so many meters. This is what works on your wing. The actual pinpoint location is based only off the GPS and isn't sent to google. Google only needs the map coordinates to download. Your GPS is what tracks you on the map. This is why google maps always load in blocks.
To fully understand a map system you must learn how maps work and be educated in the art of cairegraphy
I think the real concern is that brooklynite was seeing himself moving through traffic while he was actually stationary. I can understand that perhaps the GPS got the wrong co-ords and the incorrect map was loaded showing him in another location, but you would still expect him to be shown stationary in the wrong location. So why would it show him moving when he was stationary?
The fact that he was moving on the map means the data must have been coming from another device doesn't it? How else could you explain it?
I would be concerned too.
neoobs said:
.... Did it locate you within so many feet? or was it a real location?...
Click to expand...
Click to collapse
A real location about 50 miles away from my location. Somewhere I have never been since I have had this phone so it cannot be using the old data in my phone as sometimes it shows my locations from "last night".
...possibly it pulled the wrong location for that tower while using A-GPS and then this calculated the wrong GPS coordinates...
Click to expand...
Click to collapse
I always have the "use wireless networks" off, afterall, the GPS chip is one of the main reasons I switched to the G1 from my older WING.
....
I have to add that I am amazed by the GPS accuracy, it even notices when I cross the stree, turn into a driveway or the side of the street I am standing on. When I switch to Sat. view, it literally shows my exact spot on the sidewalk, not in the middle of the street like a car GPS does.
Probably getting too far off topic but car GPS units are just as accurate, it's just that most of them have a correction feature to fudge your position onto the nearest road on the map if for some reason it is not. For the most part a driver doesn't care where he is on the road in relation to the curb....only that he is on the road he thinks he should be on.
Related
New to the forums, and betting this is a stupid Question, but I was wondering if there was anyway to tap into the GPS locater(built in for emergency calls such as 911) and use that for a GPS application, If the Wizard even has one built in, I would imagine that it does, but anways wondering if its possible, and if anyone has any incite into how to use this/turn it on?
There's no GPS in the wizard.
markgamber said:
There's no GPS in the wizard.
Click to expand...
Click to collapse
Emergency services can locate your phone fairly accurately using triangulation from the gsm phone masts, using network data. There was a company selling a tracking service such as this for mobile users a while back, but I forget the details.
yeah ran into that service a while back, but the main way to get to it was to buy two handsets and pay for their cheap data service and put the other handset in someones car or whatever and use the 1st handset to track them...
I think that navizon.com has a program like that. theres a trial version for free. Doesnt google maps also use that technology?
hmm try google map 2.0 they show u wat ur location is without GPS
try http://forum.xda-developers.com/showthread.php?t=349188
I've tried both of these apps and both aren't worth a crap to me. They get my location in the right state, heck even the right city...almost. But I can't get it to be consistent let alone even half right.
I tried em both out and would like to know what I have been doing wrong since everyone else says that they are "great."
Thanks,
Ivan
It's already been said, but get Google Map 2.0...I installed it a few days ago, and it's not bad. I'm usually within 2000ft. of the calculated location.
Bad Karma said:
I've tried both of these apps and both aren't worth a crap to me. They get my location in the right state, heck even the right city...almost. But I can't get it to be consistent let alone even half right.
I tried em both out and would like to know what I have been doing wrong since everyone else says that they are "great."
Click to expand...
Click to collapse
The only thing you did wrong was expect triangulation to work like you're watching CSI. In the real world, there is signal bounce, interference from trees, buildings, and other radio transmissions, and a whole host of other nameless error-creating problems. Radio triangulation is severely limited, but considering this sort of feature wasn't even available as a free application (much less being built into a mapping software as robust as GMaps) until VERY recently, it's pretty good, if you don't have GPS. You can buy a dongle to attach to your MDA, or you can suck it up, and deal with generally inaccurate location.
Trying it again...I thought that I had 2.0 but maybe not...I'll let you know either way how it comes out this time.
-Ivan
Ok much better...however it is still like 4 miles!!! off.
Does it update when in travel or how/when will it become more accurate??
Thanks agian,
Ivan
Google Maps 2 has "My location"
I dunno if you knew but Google Maps has been updated now and it offers My location - which is pretty close what GPS does. It gets your position through cellular towers and then it locates you within half a mile if I'm not mistaken...
Try it and c if it works 4 u
Myrddin Wyllt said:
It's already been said, but get Google Map 2.0...I installed it a few days ago, and it's not bad. I'm usually within 2000ft. of the calculated location.
The only thing you did wrong was expect triangulation to work like you're watching CSI. In the real world, there is signal bounce, interference from trees, buildings, and other radio transmissions, and a whole host of other nameless error-creating problems. Radio triangulation is severely limited, but considering this sort of feature wasn't even available as a free application (much less being built into a mapping software as robust as GMaps) until VERY recently, it's pretty good, if you don't have GPS. You can buy a dongle to attach to your MDA, or you can suck it up, and deal with generally inaccurate location.
Click to expand...
Click to collapse
Actually google maps DOES NOT use triangulation..it will just show ur position based on a single cell tower and the signal strength being calculated by your phone..
So I tried my Google Maps 2.0 on the fly today...
It told me that it wouldn't work because I did not have a "data connection" and that I needed to contact my "service provider" to be able to utilize that function... (Or some crap like that)
What am I doing wrong now??
Thanks guys,
Ivan
I'm trying to figure out if anyone else is having this problem.
Got my G1 on the 21st. been playing with a few things and the laundry list of UI annoyances is getting longer by the minute.
but overall quite impressed. Here's a weird one.
Google Maps (on G1 of course) cannot locate my phone - at all - with wifi OFF and gps OFF.
I am in a 3G zone. Google Maps on my HTC Touch worked fine (EDGE only of course)
So I looked around and found a reference somewhere stating that cellid geolocation does NOT work in 3G areas.
Is this true of all 3G phones?? If so it's very strange - because I like to keep 3G on but when I am indoors or for that matter when I want to save battery I turn off GPS and wifi.
So why the hell would they not be able to geolocate by cellid?
I tested it on my G1 and it's true - as soon as you turn off 3G (Settings->Wireless Controls->Mobile Networks) then cellid Geolocation works fine.
Just thought people might want to know and I'm curious if anyone else has the same problem.
Nick
I heard from a network engineer that all of the 3G hardware was rapid deployed and configured to minimum specs which happened to NOT include enabling aGPS. It was either an oversight or a timesaver. This will be fixed, it is a known issue. All the techs are still in the middle of the initial deployment and rapid expansion before the end of the quarter.
I HOPE to god Tmo can stop the ATT commercials that brag about the fastest network in the US after this quarter.
that only kind of makes sense...
I mean sure - it's all new etc...
but the point is that the network is not doing the a bit of the aGPS - google is.
Google does a lookup of the cellid in its database - and presumably does not have any information on the new cellids.....YET.
I just find that weird - I am in the metropolitan LA area and you would think with all the hoopla of this launch and the financial might of google they could have gotten it together by now - I mean these towers didn't go up yesterday...
Nick
syrusfrost said:
I heard from a network engineer that all of the 3G hardware was rapid deployed and configured to minimum specs which happened to NOT include enabling aGPS. It was either an oversight or a timesaver. This will be fixed, it is a known issue. All the techs are still in the middle of the initial deployment and rapid expansion before the end of the quarter.
I HOPE to god Tmo can stop the ATT commercials that brag about the fastest network in the US after this quarter.
Click to expand...
Click to collapse
nickybee said:
Google does a lookup of the cellid in its database - and presumably does not have any information on the new cellids.....YET.
Click to expand...
Click to collapse
erm, is that how aGPS works on the G1? That's stupid. I was under the impression that it worked like normal aGPS... I.E. -
Phone: Where am I?
Tower: You are @ 33.12345/32.12345 accuracy 2000 meters
Tower: GPS sattelites G51, T85, R14 are 3 strongest
Phone: Fed GPS data to GPS radio, warm start for 10 sec lock as opposed to over a minute for a cold start lock.
And I am also under the impression that alot of the 3G hardware wasn't configured with the appropriate data (position with est of accuracy based on closest towers and affinity and the 3 strongest GPS signals for that area). The issue was noticed and any new hardware should be fine. Problems will be resolved as the expansion portion of the project begins and all of the areas are revisited.
Where did you get your info nickybee?
aad4321 said:
agps works fine with me on 3G....
also under settings...security and location.... if you look under "use wireless networks" it says with that turned on, it uses wifi and cell towers for location. I would imagine with this off, it will not geolocate through towers...
Click to expand...
Click to collapse
yes that was turned on on my G1 of course.
and no it still doesn't work.
nick
hey syrus - I didn't mean aGPS - I was just referring to the (a) part of the GPS.
i.e. there is no Phone saying "Where am I"
it goes
GMaps application: "What's my cell id?"
Phone: "It's ABC1"
GMaps application: "Hey Google dbase - where's cellid ABC1"
Google: "ABC1 is at 33.12345/32.12345 accuracy 2000 meters"
As to where I get my information from it's out of my ass
I accept that I could be totally wrong - but I assume that google does not go to the carriers for cellid information - it just drives around with the mobile vans and captures GPS data for Wifi and cellid simultaneously. Since the towers are quite new - their data has not been captured yet
Nick
syrusfrost said:
erm, is that how aGPS works on the G1? That's stupid. I was under the impression that it worked like normal aGPS... I.E. -
Phone: Where am I?
Tower: You are @ 33.12345/32.12345 accuracy 2000 meters
Tower: GPS sattelites G51, T85, R14 are 3 strongest
Phone: Fed GPS data to GPS radio, warm start for 10 sec lock as opposed to over a minute for a cold start lock.
And I am also under the impression that alot of the 3G hardware wasn't configured with the appropriate data (position with est of accuracy based on closest towers and affinity and the 3 strongest GPS signals for that area). The issue was noticed and any new hardware should be fine. Problems will be resolved as the expansion portion of the project begins and all of the areas are revisited.
Where did you get your info nickybee?
Click to expand...
Click to collapse
i never used the built in gpa, so far.
I use my bluetooth keychain gps. had it from my old excalibur.
works great
nickybee said:
GMaps application: "What's my cell id?"
Phone: "It's ABC1"
GMaps application: "Hey Google dbase - where's cellid ABC1"
Google: "ABC1 is at 33.12345/32.12345 accuracy 2000 meters"
Click to expand...
Click to collapse
Erm, you know now that I look at it Google is implementing SOMETHING new, I don't know how far they are taking it. Traditional aGPS has been around for a long time now, Google was never involved. I believe that at this point, with this version of Android things are still working the way they always have.
But! Did you notice the setting also indicates that the phone can find your location by wifi stations? I BET google receiving GPS data from users while they are connected to WIFI networks.
And then there's things like this below... ahh
http://arstechnica.com/news.ars/post/20071116-its-official-google-planning-700mhz-bid.html
Who knows, but I think as far as cell tower based aGPS is concerned android sticks with the basics. It's one data packet sent to the tower, and one back, rather than setting up a connection making a database query and receiving a reply.
They probably envisioned something like...
Phone: Where am I?
Tower: Shiii I dunno where you aaat?
Phone: Grrr, Google! I am connected to wifi access point "ATT" with SSID:12345678945 Where am I?
Google: Looks like syrusfrost was there last week, he was at 32.12345/33.12345 and he used GPS satellites.....
I really don't know how google is doing the Wifi geolocation, they may be parsing some of the wardriving databases out there for the major metro areas, hell when you drive with maps and wifi on you may be wardriving for google, wouldn't that be interesting...
Mikey1022 said:
i never used the built in gpa, so far.
I use my bluetooth keychain gps. had it from my old excalibur.
works great
Click to expand...
Click to collapse
Hows the battery life?
Hi all,
I did search the "General" Forum, but didn't find much. Today I tried the built-in GPS for the first time, with demo versions from copilot and Navigon mobile navigator. Weather condition was cloudy/foggy (1000m/3000ft cloud base, "Hochnebel") and it was snoming a bit. Bluetooth and WLAN were turned off. AGPS had a recent update.
Unfortunately, the system was unusable. The gps got a fix after about 10 seconds with 7 to 8 satelites in range; but basicly trouble was that it was lagging and skipping a lot. I don't mean serial communication, both programs reported position updates every second, as it's supposed to be.
But in the raw output speed jumped from 0 to 100kph every 5 seconds (I was diving 100kph constantly) and position updates were sometimes fluent but then again only every 3 seconds a new position (= 3 times same NMEA packet). Obviously this confused the nav software(s) a lot.
In addition to that the GPS position is reported incorrectly 300m to the south. I can reproduce the error constantly, If I drive NS direction, it will only report a wrong position on the street, but driving EW is not possible, it will always set the car on parallel streets and will recalculate the route constantly.
Is this a known problem on Leo and is there a fix? Obviously the intermediate driver here in the forum will help with the skipping, but not with the off-position reports.
Thanks, mc7
edit: reload agps data over 3G connection or WLAN. it seems that active sync download corrupts the agps data.
Haven't experienced anything like this myself and I was doing a 160km trip in similar conditions this past Friday so I don't think it's a known fault.
My suggestion would be to try again and if it continues get your set replaced.
Hi. A few things spring to mind from my time selling (dedicated) GPS devices.
Thick Fog/snow clouds block more of a signal than any other type of weather short of trees.
Some types of Tinted/Reflective/Heated windows (especially the type the mondeo use, if I remember correctly) can seriously affect the signal.
The angle that the device is positioned on the dashboard, and hence the angle the GPS antenna presents to the satellites is also critical.
Test the positioning on a fairly clear day, with the phone well exposed to teh sky, and no surrounding trees/houses/tall buildings, and see if the accuracy is still off. If it is, then the gps is dodgy and you should get it replaced. If it is accurate, then start looking for interference in your car.
No lag with copilot here, very accurate road positioning
ahhhh finally, solved again It seems that somehow the agps data got corrupted via activesync synchronisation. I turned off the "download via activesync" option in quickgps and reloaded AGPS data over the 3G connection. Now everything is in working order, no lagging, position accurately aquired, only a bit slow, like 10meters behind actual position. But that I had with my old diamond as well, it's not a draw back. btw, weather conditions were the same...
thanks again for your help.
AGPS has nothing to do with sync. I think you are confusing this with QuickGPS.
pedmond said:
AGPS has nothing to do with sync. I think you are confusing this with QuickGPS.
Click to expand...
Click to collapse
AGPS data (quickgps) can be downloaded via activesync in stead of over-the-air services.
Hmm, I though AGPS wasnt anything to do with QuickGPS.
As I understand it
AGPS uses phone signal to triangulate the phones location
QuickGPS downloads the position of the satellites.
loomx said:
Hmm, I though AGPS wasnt anything to do with QuickGPS.
As I understand it
AGPS uses phone signal to triangulate the phones location
QuickGPS downloads the position of the satellites.
Click to expand...
Click to collapse
AGPS comes in two forms
http://en.wikipedia.org/wiki/AGPS
loomx said:
Hmm, I though AGPS wasnt anything to do with QuickGPS.
As I understand it
AGPS uses phone signal to triangulate the phones location
QuickGPS downloads the position of the satellites.
Click to expand...
Click to collapse
Correct, that's my understanding as well. With the detail that AGPS is actually more than simple triangulation.
Nope, see wikipedia entry on agps. HTC uses satelite data/orbit information provided via internet; it stays accurate for about a week hence the weekly updates. your gps will work without this data, however, since it needs to calculate satelite trajectories by itself it will take longer to get a fix from cold start.
and if this help data was downloaded incorrectly, it obviously is possible that the receiver reports a wrong position. But, as stated, reloading the QuickGPS data and turning off activesync loading of the data solved the issue.
What you mean with triangualation is google maps. it gets the signal strength from neighbouring base stations and their cell ids and looks up their position in a large database online. with the base stations' exakt positions and the signal strength of each one, one is able to estimate the current position through triangulation; however since this method does not account for multipath propagation or reflection off wet walls or similar, it can only be taken as rough estimate.
****************************************************************
"EDIT" UPDATE (7 oct. 2010)
Well you dont need to go actually much further then this first post!
Things got out of context over here, furthermore I decided to give
my external gps receiver a break and run some more tests with
the internal one of my SGS.
And the results I got were much better than any
other phone I tested before. Except the ones with a build-in SirfstarIII chipset.
If you have Gps issues,Just move on to this thread:
2nd edit (20 Oct, 2010): That thread was removed without any warning or explanation so I posted the videos in another thread:
http://forum.xda-developers.com/showthread.php?p=8903056#post8903056
END EDIT
RCinFLA said:
Like to share my experience as cellphone chipset designer and my dealing with various parties involved with GPS in phones.
Many of the issues are caused by business interests involved and there are quite a few parties plying to control location based services revenue stream.
SUPL, secure user plane protocol AGPS was created by network operators interest in mine, with the objective of putting them in the controlling position when it comes to extracting revenue from location based applications on their network.
Control plane AGPS is a general system where network operator independent entities can create a assist server along with possible services offering. They can encrypt their access to allow only subcribed (paying) users to access their service. The network operators has little control over this scheme.
With SUPL, in most cases, network operators outsource the location server function. Network operator hold location of their cell tower, as a total database, in close confidence. The network tower locations are also very dynamic over time. I believe the AGPS contractors don't get reliable and timely updates from the network operators.
Then there are third party business like 'Skyhook' which is trying to work around the network operator roadblocks by establishing a 'ponzi scheme' server database. If your phone has a good GPS location lock and detects a WiFi network, Skyhook's background app will have your phone send a message to their server reporting the SSID of the WiFi and its location. They then sell their server AGPS service to other companies, like Motorola, for inclusion in their phone software. Motorola may run into conflict with network operators. A network operator might refuse to buy a Motorola phone model with Skyhook installed on it. I noticed from the Captivate forum that the ATT version of Galaxy S has Skyhook capability.
Google is the 900 pound gorilla and is trying to wrestle control of location based services from network operators.
Finally there are the GPS chip manufacturers. Almost all of them have an AGPS server scheme of their own and try to promote it. The frontend processing (up to recovery of raw 50 bps satellite data) has unique hardware and firmware that are considered proprietary by the GPS chip manufacturer. In most cases a phone manufacturers like Samsung or Motorola are not allowed to have the software source code for this firmware or information on the actual interface protocol to the GPS chip. They are given a bundled binary file that the phone manufacturer software just dumps to the GPS chip at startup.
It is now up to the phone manufacturer to implement the GPS chip and antenna systems (along with WiFI, Bluetooth, Near Field Comm, and multi-band cellular) and provide software interfaces and drivers necessary to run the GPS function.
For size and cost reasons most recent GPS chips rely on the main application processor within the phone to actually do the GPS fix calculations. The software for this is provided by the GPS chip supplier but it must be coordinated with the particular applications processor chip used by the phone. It must share processing time slicing with the apps processor and work with operating system software resources such as RAM and ROM management running on the phone.
This is the first obsticle as most of the GPS chip suppliers have little expertise in the OS's that may be used (like Android or Symbian). The phone manufacturer usually has to provide help to create and debug the GPS driver software but the drivers are responsible/owned by the GPS chip supplier. There can be unique hardware/software interfaces that must be dealt with, like providing GPS TCXO calibration and cellular corrected frequency timebase to the GPS chip.
Then there is the OS's GPS interface. There can be translation software layers involved here. One such interface is based on GPS NMEA protocol but with additional hooks for things unique to phone operation like battery saver power strobing, and the complicated Secure User Plane or Control plane interface.
The AGPS system design landscape is litered with intellectual properties (patents) by many parties. Qualcomm is a dominate player here since their aquistion of SnapTrak company years ago. Royalties are paid to Qualcomm for every WCDMA phone sold, not only in AGPS area, but on basic CDMA patents used in a UMTS (Wideband CDMA) phones.
Now as to Samsung Galaxy S implementation of Broadcom GPS.
I think there is a lot of evidence that Samsung had early issues with the GPS antenna contact hardware. This has probably been corrected on recently manufactured phones.
I think the firmware supplied by Broadcom has the bandwidth of the correlators tighted down to provide greater sensitivity. This is great as long as there is a very good AGPS system to provide initial satellite ephemeris data. Without a good AGPS network providing satellite information the initial search and lock can take a very long time with narrow bandwidth frequency bins.
I have not seen evidence with my experience that my two Vibrants are receiving any reliable AGPS information from the T-Mobile network. They do seem to get rough Almanac satellite info from Google or other third party apps. These may be based on WiFi detection more then T-Mobile cell tower locations.
In LBStest I noticed that GPS Operational Mode has been set to 'Standalone'. I interpret this to mean AGPS is deactived. I don't see any difference when I switch to MS based assist, and clear the GPS saved memory to prevent it from prejudicing time to first fix lock test. Switching SUPL server to supl.google.com and port 7276 (with MS based operational setting) just seems to make my phone lockup for short periods of time.
Once phone does get full lock on satellites its performance is quite good. (my two Vibrant's were purchased in early Feb 2011). It rivals my Garmin SiRFstar III based GPS unit in locked on sensitivity while inside a building.
I think the AGPS system issues will get worked out over time.
The Qualcomm based CDMA2000 systems (like Verizon) will likely have better initial coordination on AGPS system operation. CDMA2000 also provides network timebase directly compatible with GPS.
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Click to collapse
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All this nagging about GPS.....that it is not working in many devices and it's working in other many.....and of course I am talking about those ones who still would go for ONLINE gps navigation.....
In my humble opinion, what you guys should be asking yourselfs and the big corporations is, why nowadays, 99% of the smartphones(so not just sgs), even the most expensive ones are build with weak, less capable internal gps receivers, forcing users to go online(celular network /a-gps) or using external bluetooth gps receivers to get stable satellite fixes that means stable navigation.
Years ago, many of the first smartphones came with sirfstar chipsets or alike , so once again, why not now? That's the question that should not be ignored or forgotten.
A friend of mine, that would not dare to pay more than a 100 box for a phone, bought an ancient ETEN device on a sale for 40 box with that old windows mobile 5 and guess what...the internal gps get fast fixes just like any standalone gps device because it got the same sirfstarIII chipset
Why the heck, the expensive so called high-end smartphones of today are not build with better gps chipsets? Why A-gps? So we are forced to get data accounts?
And what happens when I want to navigate abroad? Roaming?
For data transfer and internet I use wifi; I have it at home and I find hotspots everywhere...I will save those extra 120 euros(or more) per year (data account costs)
And nobody will force me to get one(internet/data account); not even for gps navigation that I so much use..
I use gps navigation only offline, using a external bluetooth device on a daily basis and, many times abroad; it works like a charm on my SGS; and I am talking about serious GPS car navigation software like iGo, Sygic, Navigon etc. .
Don't even use Google maps or alike.
I cannot tell you how my sgs is doing on online navigation, I dont have a data account so I wont even try it.
But once Samsung get this online gps navigation thing fixed, you guys should concentrate your energy on the real issue:
The A-gps scam
And for all the corporations out there: Just deliver a device with a capable gps chipset and you will sell millions..
And for all the users out there: Just get a good compact external bluetooth gps receiver and stop nagging....
Thanks to 3rd party developers, the Android OS on my SGS can be "fooled" and I can connect any navigation software to my bluetooth gps receiver threw programs like Bluetooth Gps Mouse Unlimited and Gps Provider.
I do have to " allow mock locations" at settings first...
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¿Ein? You don need data to get GPS fix, A-GPS is only an aid to get faster fixes
I thtink you're a littel misinformed
LOL.. o boy.. the AGPS is to help say if your indoors so you can get a faster lock... the phone will work without it.
Ummm I can see why you would think what you think, but I do believe you are wrong.
Firstly: as far as I'm aware, the SGS has the same GPS chip as the latest TomTom standalone unit.
Secondly: I guess AGPS is a data feature, it uses the triangulation of cell towers and pulls information to assist a sat lock, but it is not really a different way of using GPS. Ultimately you still need to get a sat lock to use a GPS App.
So it may speed up this lock, but it won't replace it. It just means it'll take you a little longer to get a sat lock than without it.
So you have the choice use it or don;t use it, no-one is forcing you to use data.
Logicalstep
Oletros said:
¿Ein? You don need data to get GPS fix, A-GPS is only an aid to get faster fixes
I thtink you're a littel misinformed
Click to expand...
Click to collapse
Lol those online translators dont work that smoothly...
I don't need a data/internet account to use celular networks aid, that means a-gps.That mean going online via 3g or 2g...
But IF I don.t have a data/internet account added to my phone subscription, my phone costs will be much higher depending on my use....
You are missing the point anyway...
betoNL said:
Lol those online translators dont work that smoothly...
I don't need a data/internet account to use celular networks aid, that means a-gps.That mean going online via 3g or 2g...
But IF I don.t have a data/internet account added to my phone subscription, my phone costs will be much higher depending on my use....
You are missing the point anyway...
Click to expand...
Click to collapse
No, you're missing the point, you don't need any kind of data connection to use GPS, you can use it offline
Exactly...already the first line of Wikipedia says it: "Assisted GPS, generally abbreviated as A-GPS, is a system which can improve the startup performance of a GPS satellite-based positioning system."
There is, however, a related issue w/r/t A-GPS and a data account. Back on WinMo, I could download the ephemeris data to speed up the GPS fix for one week in advance (I think it was called QuickGPS or something on my HTC TouchHD, also had sth. like it on an old Eten). This allowed you to get a quick fix for said week, even without a data connection. Android, on the other hand, seems to download this data on the fly - meaning that if you don't have a data account you will experience a slow fix until your almanac has been filled "naturally" by the satellites you're seeing. I experienced that while on vacation this year without a roaming data contract - it took me a good 3-5 minutes to get the first fix and it was good from there on (well, as good as the SGS GPS gets ). I'd love to have some tool that does exactly what QuickGPS did, but I am not aware of anything like it.
TriC_101 said:
LOL.. o boy.. the AGPS is to help say if your indoors so you can get a faster lock... the phone will work without it.
Click to expand...
Click to collapse
I have always smile in my face when someone thinks he can get a lock indoors..
Yes in a cartoon box you can. Not in real building I'm afraid.
And for all those who think SGS's GPS is usable without A.
Try it.
You will see.
Dont post things you just caught on wikipedia.
xan said:
I have always smile in my face when someone thinks he can get a lock indoors..
Yes in a cartoon box you can. Not in real building I'm afraid.
And for all those who think SGS's GPS is usable without A.
Try it.
You will see.
Dont post things you just caught on wikipedia.
Click to expand...
Click to collapse
I can get a lock on 6-7 Sat no problem inside.... and so can lots of others.. don't know what your doing wrong but its not hard to get a lock inside.
Pics or it didnt happen
seems you all are little misinformed as to how the gps on android specifically sgs works. It is actually three systems at work here. Gps standalone without gprs and cell triangulation which gets lock within a minute same as standalone bluetooth units (they also take up to a minute from cold boot but because generally it is plugged in the car lighter and always on people think its blazing fast).then you have agps that downloads preloads data regarding satellite location in regards to your position via network instead of downloading same data directly from satellite thereby saving time. Both these can be used without checking network location in settings so to recap if your network location is unchecked you are still using agps as long as you have network connection (data connection that is).and samsungs system for agps being better than others cause it downloads data for while week as opposed to others downloading data everyone gps is turned on. Third level is network triangulation via cell towers that gets you that instant lock at the cost of accuracy useful mainly to let apps get your general location without having to engage real gps thereby saving power as well as give maps a chance to start calculating route while gps is still getting lock therefore appearing to operate faster.
Idan73 said:
Gps standalone without gprs and cell triangulation which gets lock within a minute same as standalone bluetooth units (they also take up to a minute from cold boot but because generally it is plugged in the car lighter and always on people think its blazing fast)
Click to expand...
Click to collapse
Standalone gps's got their batterys, and thus they start "warm".
Thing is, standalone SRIF3/4 gps gets a warm lock without any AGPS nor network triangulation within 5-10 seconds. SGS (and bunch of top-of-the pack devices) cant come even close to that.
the GPS on the SGS works fine offline
i don't even have data on when going on long road trips
you just need an offline GPS software with maps, like CoPilot or some other one you like
xan said:
Standalone gps's got their batterys, and thus they start "warm".
Thing is, standalone SRIF3/4 gps gets a warm lock without any AGPS nor network triangulation within 5-10 seconds. SGS (and bunch of top-of-the pack devices) cant come even close to that.
Click to expand...
Click to collapse
Sure they do. Sgs warm lock is 5 to 10 seconds as well. To test get the lock first then turn of data and network lock then start gps.restart of the phone same as restart of the standalone counts as a cold boot and takes about minute.
xan said:
Pics or it didnt happen
Click to expand...
Click to collapse
Here ya go.... I don't have to prove anything just look on youtube.. This is the phone on for just 10sec.. if I had waited it would get down to about 10 feet... this pic was taken in a room where I get the lowest signal. and I live in a Condo with 2 foot concrete walls.. I don't have a digital camera.. this was taken with my old Samsung dumb phone.. but it does prove you can get a lock inside no problem.. also if i'm in a house I can get 6-7 sats to lock in the condo 5 at the most in that room.
only 3 sats and maybe the walls are thin
Polarfuchs said:
only 3 sats and maybe the walls are thin
Click to expand...
Click to collapse
LOL Trust me the walls and not thin.. i'm on the 10th floor of a 25 floor Condo complex. I get alot more signal is a house.. Now my X10 can get about 7 Sats locked in the same room. and down to 5 feet. but the point was you can get a lock inside..
I'll try it.
I live in a 3 stories house at ground floor. The shutters are down and I'm 1 meter away from the windows.
After 3 Minutes I get 5 sats in view but none used.
I'll hang on.
Even after 10 Minutes I only have 5 satellites in View and zero in Use.
So no fix for me.
The numbers on top of the bars are from 15 to 25.
Logicalstep said:
Ummm I can see why you would think what you think, but I do believe you are wrong.
Firstly: as far as I'm aware, the SGS has the same GPS chip as the latest TomTom standalone unit.
Click to expand...
Click to collapse
Most of Tomtom devices got a SiRFstarIII™ GPS chipset
If the GS got such one the amount of GPS threads in this Forum would be reduced considerably
What is your awareness based on?
Oletros said:
No, you're missing the point, you don't need any kind of data connection to use GPS, you can use it offline
Click to expand...
Click to collapse
Idan73 said:
seems you all are little misinformed as to how the gps on android specifically sgs works. It is actually three systems at work here. Gps standalone without gprs and cell triangulation which gets lock within a minute same as standalone bluetooth units (they also take up to a minute from cold boot but because generally it is plugged in the car lighter and always on people think its blazing fast).then you have agps that downloads preloads data regarding satellite location in regards to your position via network instead of downloading same data directly from satellite thereby saving time. Both these can be used without checking network location in settings so to recap if your network location is unchecked you are still using agps as long as you have network connection (data connection that is).and samsungs system for agps being better than others cause it downloads data for while week as opposed to others downloading data everyone gps is turned on. Third level is network triangulation via cell towers that gets you that instant lock at the cost of accuracy useful mainly to let apps get your general location without having to engage real gps thereby saving power as well as give maps a chance to start calculating route while gps is still getting lock therefore appearing to operate faster.
Click to expand...
Click to collapse
LOL... Lets put things in perspective :
1) Wich car navigation software do you use
2) when you UNcheck wireless networks =a-gps(in location and security) and you CHECk "use GPS satellites = build-in gps receiver and then you go outside, you start your car navigation software in you gs( taking into consideration that you have the righ map installed) how long does it take to get a fix so you can start driving?
3) Do you know the difference between a cold and warm start? Why the heck some of you mention car lighters????
Please just answer me these 3 questions and meanwhile I will post some educative information
It worked once when I first tried it but ever since then for example when I go into maps, it's always searching and searching. the local filter in the bing search doesn't work either...
What can I do? Anyone have the same issue?
I've managed to bring up my location but it's highly innacurate. I downloaded the GPS app that is available in the marketplace and it's showing the wrong latitude/longitude coordinates as well.
Highly annoying.
Do you have Weatherbug installed? This app seemed to break my location service too. Sometimes it showed my location a few hundred miles away... I then uninstalled Weatherbug and somehow, after a while, it was working again -strange.
Now it's very accurate and fast.
Then go into settings -> "find my phone" and check the upper box for "saving the location".
It could also be a problem with your carrier -the location service first takes the location via A-GPS which is you provider's responsibility.
GPS might take a few minutes to determine the exact location.
I called 3 and they said I could arrange a door to door exchange but first they advised me to go to the 3 store nearby and use my SIM in another omnia 7 to see if it works.
Surprise surpise, after the call, the GPS is now perfect. I wonder if they did something at their end lol.
So after a few days use, I have come to the conclusion that the GPS doesn't seem to work well indoors, but as soon as I go outdoors, it's tracking me just fine.
digger1985 said:
So after a few days use, I have come to the conclusion that the GPS doesn't seem to work well indoors, but as soon as I go outdoors, it's tracking me just fine.
Click to expand...
Click to collapse
GPS will absolutely NOT work indoors because it needs nearly line-of-sight to the GPS satellites above. The roof of a car might work but the roof of a house won't.
Indoors the phone is using A-GPS, the triangulation of cell towers of your network operator. It's very inaccurate and might get no location at all.
See my post here: http://forum.xda-developers.com/showpost.php?p=9417735&postcount=2