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Okay, so here's the deal. If we get AGPS working in some way, we can get MUCH quicker GPS fixes (30 seconds or less). I'm the coder for GPSToolPro you can find here in the Software subforum of the Raphael forum. I'm hoping to incorporate this into the program in some way.
I've managed to obtain the Lat/Long coordinates using Cell Tower information and Google.
There are two ways to solve this issue.
#1
Now, I'm looking to use these Registry Keys
HKLM\Software\HTC\SUPL AGPS\ServerIP
HKLM\Software\HTC\SUPL AGPS\ServerPort
HKLM\Software\HTC\SUPL AGPS\GPSMode
The plan is to set the ServerIP to 127.0.0.1 and run any port. Then the GPSToolPro will listen in on the port number on the device and RESPOND with the Lat/Long information obtained from Google. Right now, what I need is, somebody who has AGPS working with their provider to try to packet sniff and get see how we can make our own AGPS server run on the device. GPSMode mode will be set to "1", not "2". This is specific to the QualComm's GpsOne unit. The values are the following:
0 - Standalone - Your handset has no connection to the network, and uses only the GPS satellite signals it can currently receive to try and establish a location.
1 - MS Based - Your handset is connected to the network, and uses the GPS signals + a location signal from the network.
2 - MS Assisted - Your handset is connected to the network, uses GPS signals + a location signal then relays its 'fix' to the server, which then uses the signal strength from your phone to the network towers to further plot your position. You can still maintain voice communication in this scenario, but not 'Internet/Network service' ie Web Browser, IM, streaming TV etc..
4 - MS Assisted/Hybrid - Same as above, but network functionality remains. Normally only in areas with exceptional coverage.
Click to expand...
Click to collapse
I haven't been able to find the signal strength of the tower I'm connected to yet so right now, I'm limited to mode 1. Also, I can only find information on the tower I'm currently connected to, not all of them so I can't try cell tower triangulation yet.
This solution is limited to only working with HTC GpsOne devices.
#2
We can also try using the IOCTL_GPS_WRITE_ASSISTED command. This command will directly send the AGPS info to the GPS device. The question is, how do we send this information? I believe we need to get a AGPS signal first, use IOCTL_GPS_READ_ASSISTED, parse that information, figure out the format, get Lat/Long from Google, format it in the same way as received from IOCTL_GPS_READ_ASSISTED and send it back with IOCTL_GPS_WRITE_ASSISTED.
This universal for all Windows Mobile phones.
For method #1, I need somebody who has an HTC device with a working AGPS signal (from their provider or whomever).
For method #2, I need any Windows Mobile device that has a working AGPS signal.
I say method #1 requires HTC device because supposedly AGPS isn't standardized and one manufacturer's AGPS format may differ from another.
Hopefully, with the your help, we can get this working.
let's support CLShortFuse iniciative, it would be incredible if we would get AGPS working.
My AGPS (Spain-Orange) doesn't work at all. And i don't know anybody that has a working AGPS device/operator combination.
I've read around XDA that some people in the Raphael CDMA section have AGPS working, maybe we could post there to see if somebody replies and can collaborate with this project.
I was just about to post something similar. Only I wasn't as prepared with as much information. I was going to try to start a thread to consolidate the AGPS server settings for each additional carrier since I'm with T-Mobile and using an AT&T Fuze. My AGPS is not working at all. It keeps trying to connect to AT&T's Media Net and naturally, it fails.
Would it be possible to maybe create some kind of way to trick the devices into thinking that they are AT&T Fuze's and connect to the Media Net to connect to AT&T's AGPS Servers?
I Personally support this project 100%!!
Side note - Has anyone gotten AGPS working on USA T-Mobile at all? I attached a screenshot of the result of what happens when I try to use AGPS on my Fuze.
dharvey4651:
Code:
[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\SUPL AGPS]
"Network"="MEdia Net"
"GPRSConnection"="MEdia Net"
You need to change those to whatever your network is called on t-mobile
I dont know much about any of this, I have an AT&T Fuze with AT&T service, I also have the AT&T Navigator Software and an account with it, so, is there anything I can do to help? how do I know if my AGPS works or not?
dharvey4651 said:
I was just about to post something similar. Only I wasn't as prepared with as much information. I was going to try to start a thread to consolidate the AGPS server settings for each additional carrier since I'm with T-Mobile and using an AT&T Fuze. My AGPS is not working at all. It keeps trying to connect to AT&T's Media Net and naturally, it fails.
Would it be possible to maybe create some kind of way to trick the devices into thinking that they are AT&T Fuze's and connect to the Media Net to connect to AT&T's AGPS Servers?
I Personally support this project 100%!!
Side note - Has anyone gotten AGPS working on USA T-Mobile at all? I attached a screenshot of the result of what happens when I try to use AGPS on my Fuze.
Click to expand...
Click to collapse
Actually, there are AGPS standards. Today, most GPS chipset vendors use their own AGPS platforms. However, that is rapidly changing. To my knowledge, most (including Snaptrack/GPSOne, aka Qualcomm) support 'secure user plane location architecture' or SUPL. This is a standard adopted by the OMA or 'Open Mobile Alliance' (www.openmobilealliance.org). The OMA is basically almost all of the heavy weights of wireless including Silicon manufacturers, Handset Vendors, Carriers, etc.
Currently, the OMA has ratified SUPL v1.0 and the standards body and members are working on the next version - 2.0.
What is SUPL? In a nutshell, SUPL is designed to support location determination regardless of the location server used by the mobile carrier. As the number of applications grow for LBS, so does the need by developers to work across location platforms and mobile device hardware manufacturers.
CLS, I am a bit confused as to your intentions. The Raphael supports artificial ephemerids (Qualcomm's GPSOneXTRA) which cut cold-start TTFF down to under 10 seconds. Using cellular triangulation won't buy you much.
Is there another reason I am missing here?
Da_G said:
dharvey4651:
Code:
[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\SUPL AGPS]
"Network"="MEdia Net"
"GPRSConnection"="MEdia Net"
You need to change those to whatever your network is called on t-mobile
Click to expand...
Click to collapse
I'll try this now. I think my data is called "T-Mobile Data"
fatguybp said:
I dont know much about any of this, I have an AT&T Fuze with AT&T service, I also have the AT&T Navigator Software and an account with it, so, is there anything I can do to help? how do I know if my AGPS works or not?
Click to expand...
Click to collapse
If your AGPS is working, your GPS should lock in just under a minute every single time, sometimes even faster. With my old Sprint Touch(back when I was with Sprint), I was able to lock onto upwards of 7 satellites every single time in less than 10 seconds. Now it takes 2-5 minutes every time with my Fuze on T-Mobile.
Operation619 said:
Actually, there are AGPS standards. Today, most GPS chipset vendors use their own AGPS platforms. However, that is rapidly changing. To my knowledge, most (including Snaptrack/GPSOne, aka Qualcomm) support 'secure user plane location architecture' or SUPL. This is a standard adopted by the OMA or 'Open Mobile Alliance' (www.openmobilealliance.org). The OMA is basically almost all of the heavy weights of wireless including Silicon manufacturers, Handset Vendors, Carriers, etc.
Currently, the OMA has ratified SUPL v1.0 and the standards body and members are working on the next version - 2.0.
What is SUPL? In a nutshell, SUPL is designed to support location determination regardless of the location server used by the mobile carrier. As the number of applications grow for LBS, so does the need by developers to work across location platforms and mobile device hardware manufacturers.
CLS, I am a bit confused as to your intentions. The Raphael supports artificial ephemerids (Qualcomm's GPSOneXTRA) which cut cold-start TTFF down to under 10 seconds. Using cellular triangulation won't buy you much.
Is there another reason I am missing here?
Click to expand...
Click to collapse
I've never had my Fuze lock it's GPS 10 seconds or less. NEVER. It's usually 2-5 minutes on average. Sometimes it doesn't even lock at all after standing outside in the cold for upwards of 5 minutes smoking a cigarette.
Dharvey:
I get 3D position fixes in open-sky conditions in ~6 seconds.
Under my balcony in my apartment in a highly attenuated partial-sky view I will get 3D fixes in ~20 seconds.
Indoor in my home office with a south facing window and light foliage I'll see 2D in about 1 minute and 3D almost always under 2 minutes.
At my corporate office with a re-radiating GPS antenna I'll see consistent GPS lock in ~6 seconds.
Hell, I'd love to put this in the multi-channel GPS simulator at my desk but I don't think that's a good idea.
Operation619 said:
Dharvey:
I get 3D position fixes in open-sky conditions in ~6 seconds.
Under my balcony in my apartment in a highly attenuated partial-sky view I will get 3D fixes in ~20 seconds.
Indoor in my home office with a south facing window and light foliage I'll see 2D in about 1 minute and 3D almost always under 2 minutes.
At my corporate office with a re-radiating GPS antenna I'll see consistent GPS lock in ~6 seconds.
Hell, I'd love to put this in the multi-channel GPS simulator at my desk but I don't think that's a good idea.
Click to expand...
Click to collapse
Yes you definitely have working AGPS
I made the registry changes mentioned above and I'm about to test my AGPS now. If it works I'll make a cab file to make the registry changes for everyone who may want it. (T-Mobile Only of course)
EDIT:: Making the following registry changes seems to have helped a little. My GPS locked in about 1 minute in my bedroom from a cold start(after soft-reset) It also connected to the data instead of error-ing out which was also different.
FROM:
[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\SUPL AGPS]
"Network"="MEdia Net"
"GPRSConnection"="MEdia Net"
TO:
[HKEY_LOCAL_MACHINE\SOFTWARE\HTC\SUPL AGPS]
"Network"="T-Mobile Data"
"GPRSConnection"="T-Mobile Data"
EDIT AGAIN:: I just soft-reset and from a dead cold start(GPS OFF COMPLETELY) it locked onto 8 satellites in less than a minute in my bedroom agian.
I'm starting to like this phone again.
EDIT AGAIN...Spoke too soon... It's doing it again. It was fast for 2 locks and 2 soft-resets but now it's slow again.
This is what the SUPL AGPS key looks like in my registry:
Code:
REGEDIT4
[HKEY_LOCAL_MACHINE\Software\HTC\SUPL AGPS]
"EnableAGPS"=dword:00000001
"Network"="T-Mobile Data"
"GPRSConnection"="T-Mobile Data"
"PrivacyMethod"=dword:00000003
"TLSHostName"="h-slp.mnc410.mcc310.pub.3gppnetwork.org"
"ServerIP"="199.88.233.169"
"ServerURL"="h-slp.mnc410.mcc310.pub.3gppnetwork.org"
"DynamicURL"="h-slp.mnc000.mcc111.pub.3gppnetwork.org"
"EnabledPrivacyMethod"=dword:00000001
"CloseConfirmMsgTime"=dword:0000003C
"EnableLocInfo"=dword:00000001
"ServerPort"=dword:00001C6B
"QosPerformance"=dword:00000059
"QoSAccuracy"=dword:00000032
"TimeBetweenFixes"=dword:00000001
"NumberFixes"=dword:3B9AC9FF
"GPSMode"=dword:00000002
[HKEY_LOCAL_MACHINE\Software\HTC\SUPL AGPS\DefaultSetting]
"EnableAGPS"=dword:00000001
"CloseConfirmMsgTime"=dword:0000003C
"PrivacyMethod"=dword:00000000
"EnableLocInfo"=dword:00000001
Nope. I'm not using any type of TOA or AOA, or what you and the OP are describing as "AGPS" on this handset. Network provided AGPS is disabled. Furthermore, GPS performance is somewhat better when my GSM radio is off.
Note that I am using the artificial ephemeris information provided by the Q or "QuickGPS" as most users know it.
These shots were taken in my home office scenario I described above. PDoP is pretty high (but still good) as I am in a poor visibility scenario (lots of multipath, limited sky view, etc.)
Well... I finally got AGPS working for me(at least it feels like it). My GPS is now locking onto 6-10 satellites in less than a minute every single time. Even after a soft-reset without using any kind of primer like GPSToday or HTC GPS Tool.
I'm a happy camper.
All it took was a little tweaking to the registry and now it works.
I attached a cab file to fix the AGPS.
WARNING!!! This is ONLY FOR USA T-Mobile!!
Harvey,
Are you downloading the QuickGPS file? If so, what's the age of the download?
Operation619 said:
Harvey,
Are you downloading the QuickGPS file? If so, what's the age of the download?
Click to expand...
Click to collapse
Where does QuickGPS download to? I downloaded it today but I never bothered looking for the file it downloaded.
I would suspect you are still not using network-assisted positioning. The QuickGPS file is aiding the receiver.
If you were using network assistance you would be getting rough position (<1000m) in seconds. Even indoors or your basement where there is zero GPS signal available.
Here's a quick way to test if AGPS is really working.
Set GPSMode to 1. GPSMode is normally set to 2 - it will auto-fallback if AGPS fails.
GPSMode 1 will continually try to get an AGPS fix, and not send you any NMEA data at all if it doesn't. You'll probably need to up the value in TimeBetweenFixes from 1 to at least 3 or 4, allowing only 1 second between fixes doesn't give your phone enough time to send location data to the AGPS PDE server and get a response.
Anywho, in GPSMode 1 i get no NMEA strings at all, so my agps is definitely broke
Operation619 said:
I would suspect you are still not using network-assisted positioning. The QuickGPS file is aiding the receiver.
If you were using network assistance you would be getting rough position (<1000m) in seconds. Even indoors or your basement where there is zero GPS signal available.
Click to expand...
Click to collapse
You may be right but I feel that It's still using some form of network assisted GPS because it's never been this fast before. I hard-reset and did not use QuickGPS at all and my results are the same.
Try turning off your radio to see if you still have the same TTFF.
Remember QuickGPS will download it's data in the background on a cradled connection with no cue from you, too, so make sure it didnt download \Windows\xtra.bin and inject it without you knowing
Also the QuickGPS data survives a hard reset if "ClearGPS" flag isnt set for the hard reset program or you don't have the CleanGPSData package in your ROM.
Operation619 said:
Try turning off your radio to see if you still have the same TTFF.
Click to expand...
Click to collapse
I'll try this now.
EDIT:: Seems you're right. It just locked onto 10 satellites in flight mode right in my bedroom in less than 30 seconds. WOW. Never saw it do that before.
Good catch Da G.
Harvey - are you willing to do a little test?
To test if network assistance is available and helping you might want to try the following.
This test will need to be performed at the same location in an ideal, open-sky condition with the handset in the same orientation in your hand each time:
1. Make sure your handset is free of the QuickGPS file.
2. Shut off all radios, go outside in a clear, open-sky environment.
3. Acquire 3D position fixes 10 times. Record the times it takes to acquire in seconds (aka TTFF).
4. Average the TTFFs
5. Power Cycle the handset.
6. Ensure no programs or registry settings inhibit AGPS or network assistance.
7. Make sure there is no QuickGPS file present.
8. Turn on your GSM radio.
9. Re-acquire GPS 3D position fixes in the same open-sky area 10x and record each TTFF
10. Average the TTFFs
What's the result?
I believe AGPS triangulates your location using the GSM towers.. But when you renew it thru active sync/wifi does it still helps the GPS locate you..?
The celltowers only help triangulate the phone when the satellites can't be seen. The GPS does most of the work.
kpriess said:
I believe AGPS triangulates your location using the GSM towers.. But when you renew it thru active sync/wifi does it still helps the GPS locate you..?
Click to expand...
Click to collapse
you get QuickGPS info off wifi/activesync(or even 3G data), and this info gives you moon/earth almanac that allows you to calculate the your position given SATELLITE info.... if you don't have almanac(or out of date), you have to download if from the satellite, which means a 30s lock will be extended to 1+ minute to download... bad connection to satellite means longer
AGPS is downloading data from celltowers(which have a fixed and known location) ... this requires data from 3G(or EDGE)... the GPS program, if not having a valid 3D GPS lock, will use that AGPS info to give you an estimated location, or help validify the incoming GPS satellite info
Google Maps (the WM app), when connected to WiFi, will also attempt to get your location from the known IP address(well, if you have a location aware browser i.e. latest version of FF or Chrome, maps.google.com has a button for you to get the estimated location of your computer).... this though, isn't implemented in most WM GPS apps, so not as useful if you don't use Google Maps
For the past few days, I've been dealing with what appears to be a disproportionately huge group of Evo owners (relative to other Android phones) who've been having crashes with an app I wrote that appear to be caused by the unavailability of network-based location services. I did some research, and it looks like a LOT of Evo owners have been doing things that (temporarily?) disable network-based location services in an attempt to keep the battery from dying too quickly.
Are Evo users who do this literally going into Settings and disabling network-based location services outright, or are there one or more apps/hacks that supposedly disable it only when "it's not being used"? If there are, what does an app that depends on network-based location services have to do to make sure that whatever is supposedly enabling network-based location services "when necessary" realizes that it is, in fact, necessary... and do it in a way that won't cause the lookup request to prematurely or needlessly fail?
Like I've said, I've had a few users with other phones have problems due to the app's current absolute dependency on the availability of network-based location services... but with Evo owners, it's more like a nonstop hailstorm of complaints. Rewriting the way the app handles location to eliminate that absolute dependency is my next major project, but it's going to take me at least a week or two to finish, and in the meantime I'd love to be able to find a temporary solution that I can patch and release tonight that will solve the worst of the problem for the majority of Evo users in the meantime.
Speak up brother. What is the App (so people who don't have the slightest clue as to how to relate your user name with the buggy app you have)?
I'm not sure why anyone would do this, aside from "privacy" concerns... It will not help with battery life on it's own. If your GPS is turned off, your device gets it's relative location via the cell phone tower's coordinates. This information gets transmitted to your phone regardless if you have it disabled to accept it.
They are probably thinking that if they disable it, other services won't try to update information based on your location. Instead they should just adjust any services that are auto-updating.
I can go >24hours before I need to charge my phone with moderate usage throughout the day (without using 4G). I can post SystemPanel screenshots if anyone is interested.
mattrb said:
Speak up brother. What is the App (so people who don't have the slightest clue as to how to relate your user name with the buggy app you have)?
Click to expand...
Click to collapse
OK, if it makes you happy, I didn't personally write it that way. It's a legacy app I'm helping to fix. In the meantime, I'm trying to put out as many fires as quickly as I can. That said, I'm not going to condemn the original author. All things considered, it was a perfectly reasonable decision for him to make. It was his first major Android programming project, and his immediate runtime environment was a Droid on Verizon. 99% of his Android-owning friends were Sprint or Verizon. For the most part, on Sprint & Verizon, network-based location services work really well. The app's dependency on them didn't really bubble to the surface as anything more than likely user error until lots of non-Americans started showing up with phones that couldn't be automatically assumed to have inseparably-bundled mandatory data service.
Truth be told, America is a lot like Japan -- cellular networks that are almost proprietary to the national market and work in ways that aren't necessarily consistent with the way things work elsewhere in the world, but utterly ubiquitous and totally dominant within it. I'm sure that right now, plenty of Japanese developers are writing Android apps that assume every phone supports network-level low-latency "Push to Talk" capabilities (IDEN's "killer app"), or some other feature that's ubiquitous in Japan and (almost) unheard of elsewhere. Six months from now, they're going to be scratching their heads wondering why it crashes on every phone in Europe and most phones in America (Sprint, and I think Verizon, try to emulate IDEN's PTT on CDMA by buffering the audio stream on a server, then sending a SMS to the recipient's phone that triggers its download and streaming a couple of seconds later).
Anyway, I digress. Getting back to the original question, are Evo owners who disable network location doing it manually, or are they doing it in a way that can be worked with cooperatively by apps in order to get it to automatically turn it back on when needed?
Actually, I have theory #2 about why Evo owners might be having problems, but it's pure speculation at this point. I'm wondering whether there might be Evo owners who've explicitly disabled EV-DO and 1xRTT to try and force the phone to use WiMax in areas where it might otherwise try to fall back to the older modes, and the possibility that even NON-network location service DEPENDS on EV-DO/1xRTT for aGPS data transmission of the raw telemetry data. In a way, it makes sense... the WiMax network is totally parallel to the CDMA2000 network, and it's not inconceivable that there might BE no data route between the Sprint WiMax network and the servers that handle aGPS queries. Especially if there aren't any real-world locations where Sprint WiMax is available, but CDMA2000 data is not.
If you go into the settings you can disable the network location, but there are ways for an app to ask if the user wants to turn the setting back on.
Evo owners can't disable 1xRTT otherwise standard calls and text messages won't work anymore. They can change settings if they have their MSL code such that EVDO isn't ever used however.
Well, maybe "disable" is a strong term. I know that on a Hero, there's a network setting somewhere that allows you to tell the phone, "Use EV-DO, or don't do data at all". It doesn't affect the operation of voice or sms -- only the phone's willingness to fall back to 1xRTT for internet access if EV-DO isn't available. I'm assuming the Evo has a similar setting that goes a step further and lets you dictate "WiMax or Nothing".
Here's how it could theoretically affect location services: obviously Sprint does aGPS. By law, it HAS to do it for e911 purposes. HOWEVER, I think that non-e911 aGPS lookups on Android phones get diverted through Google (or at least an aGPS service hosted by Google) unless you pay Sprint extra for navigation service. Under those conditions, if you told the phone to use ONLY WiMax for internet access, and you were in an area where only EV-DO and/or 1xRTT data were available, you could have a situation where the phone can do e911 location, but wouldn't necessarily have that info available for use by other applications (vis-a-vis most of HTC's WinMo 6 phones). If the phone couldn't use WiMax, and the user dictated "WiMax or Nothing", the phone couldn't reach Google. Without Google, there'd be no free aGPS for Android apps to consume.
The above is pure speculation, of course. As a practical matter, Sprint itself can't/won't give a coherent explanation of where the line gets drawn between Sprint and Google for (a)GPS service, which makes troubleshooting location-related problems that much more fun. Personally, it wouldn't surprise me in the least if late-model HTC phones DO have 100% of the hardware onboard to turn satellite telemetry into latitude/longitude/altitude coordinates, but the underlying software fails without realtime network connectivity anyway because it still tries to involve a server somewhere for some reason.
Look, this is what happens to me and I think it's a bug.
When I turn off GPS for a while, like for 12 hours, and then I turn it on, I still see the "Location" icon crossed out. At first I didn't know what was going on. I thought it was the GPS icon, but it wasn't, it was the location services being turned off.
So I reproduced it several times and this is what happens. When you turn off GPS for a while, the location setting will be turned off also, and it will remain off even after you turn on the GPS again. Which IS A BUG. That's not an expected behavior. So you may be right.
baiatul said:
Look, this is what happens to me and I think it's a bug.
When I turn off GPS for a while, like for 12 hours, and then I turn it on, I still see the "Location" icon crossed out. At first I didn't know what was going on. I thought it was the GPS icon, but it wasn't, it was the location services being turned off.
So I reproduced it several times and this is what happens. When you turn off GPS for a while, the location setting will be turned off also, and it will remain off even after you turn on the GPS again. Which IS A BUG. That's not an expected behavior. So you may be right.
Click to expand...
Click to collapse
My experience doesn't mirror that at all. When I turn GPS on (which I am impressed to say has it finding satellites many times faster than my old HTC Fuze) the location disabled icon changes almost immediately. I saw this a lot over last weekend when I was doing a lot of phone based navigation.
Yes, I forgot, I'm in NY, and in Manhattan very strange things happen when you go in and out the subway with signal and no signal several times a day for periods of time from minutes to an hour.
Many programs that are expected to work crash when there is no signal. Or when you run applications in the subway with no signal, the gadget freezes sometimes. Maybe this GPS thing is also one of those glitches. Maybe it's a combination of turning on or off the GPS, and then the loss of signal for a while. It still happens to me, but I got used: every time I turn back on the GPS after being disabled for MANY HOURS (12? 24?), I have to turn back on the Location setting.
merak69 said:
I'm not sure why anyone would do this, aside from "privacy" concerns...
Click to expand...
Click to collapse
I turned off network location services for one simple reason....using it caused my location to off by at least 1/2 mile. So it seemed pretty useless to me.
pixelpop said:
I turned off network location services for one simple reason....using it caused my location to off by at least 1/2 mile. So it seemed pretty useless to me.
Click to expand...
Click to collapse
It's basing your location on the information from the cell phone tower. It isn't meant to give you a precise location like GPS can (this is why its called aGPS). The point is to give a general location so that apps that need to know what city you are in (weather apps for example) can figure it out to show you information for where you currently are.
If you want precise information, turn on full GPS and you are good to go.
My point was disabling location services entirely will not save you any more battery life vs leaving network location on (excluding full GPS obviously). What will save you battery is turning off your other services (Facebook, Twitter, News, etc) to only update when you manually say so or setting their update schedules to much longer frequencies.
Here's how it could theoretically affect location services: obviously Sprint does aGPS. By law, it HAS to do it for e911 purposes. HOWEVER, I think that non-e911 aGPS lookups on Android phones get diverted through Google (or at least an aGPS service hosted by Google) unless you pay Sprint extra for navigation service. Under those conditions, if you told the phone to use ONLY WiMax for internet access, and you were in an area where only EV-DO and/or 1xRTT data were available, you could have a situation where the phone can do e911 location, but wouldn't necessarily have that info available for use by other applications (vis-a-vis most of HTC's WinMo 6 phones). If the phone couldn't use WiMax, and the user dictated "WiMax or Nothing", the phone couldn't reach Google. Without Google, there'd be no free aGPS for Android apps to consume.
Click to expand...
Click to collapse
Your phone doesn't communicate with Google. Sprint has their own aGPS servers but I think you might misunderstand what their purpose is. The "a" part of aGPS means Assisted, but only assisted in the fact of giving the chip the information it needs to lock on to the true GPS signals faster based on your current location.
For example: If you used a GPS device that wasn't assisted and its known internal satellite database was out of date, it'd have to search for awhile to location any/all satellites in the sky. On the flip side, an assisted chip can use the network server to download satellite info (ids, frequencies, etc) to show which satellites are visible for your given rough location. This enables hardware lock to happen faster.
However those aGPS servers are optional since the chip has a hybrid mode of operation:
a) If you have true GPS on, obviously it uses GPS to determine your location, down to potentially 3-4 meters.
b) If the chip can't get a satellite lock or you have true GPS turned off, the chip uses multiple known tower locations in combination to triangulate your location (based on signal strength to known towers). The fewer the towers it has access to, the less and less accurate your known location becomes. This works even with 3G and 4G disabled because it transmits the data over 1xRTT (you can easily test this in Google Maps).
In the second situation (b), I've seen where tower triangulation has narrowed my location down to 100 meters. I've also seen where it can't get a lock on multiple towers reliably such that the chip puts my "center" location as the actual location of the tower with an accuracy rating of 2000 meters. This is what Pixelpop is mentioning above about accuracy.
merak69 said:
Your phone doesn't communicate with Google. Sprint has their own aGPS servers but I think you might misunderstand what their purpose is. The "a" part of aGPS means Assisted, but only assisted in the fact of giving the chip the information it needs to lock on to the true GPS signals faster based on your current location.
For example: If you used a GPS device that wasn't assisted and its known internal satellite database was out of date, it'd have to search for awhile to location any/all satellites in the sky. On the flip side, an assisted chip can use the network server to download satellite info (ids, frequencies, etc) to show which satellites are visible for your given rough location. This enables hardware lock to happen faster.
However those aGPS servers are optional since the chip has a hybrid mode of operation:
a) If you have true GPS on, obviously it uses GPS to determine your location, down to potentially 3-4 meters.
b) If the chip can't get a satellite lock or you have true GPS turned off, the chip uses multiple known tower locations in combination to triangulate your location (based on signal strength to known towers). The fewer the towers it has access to, the less and less accurate your known location becomes. This works even with 3G and 4G disabled because it transmits the data over 1xRTT (you can easily test this in Google Maps).
In the second situation (b), I've seen where tower triangulation has narrowed my location down to 100 meters. I've also seen where it can't get a lock on multiple towers reliably such that the chip puts my "center" location as the actual location of the tower with an accuracy rating of 2000 meters. This is what Pixelpop is mentioning above about accuracy.
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You're correct that aGPS doesn't go through Google. It's presumably handled by the radio and Android is never aware of it at all.
Cell tower location/triangulation is different however. The OP is correct that it does go through Google, as the US CDMA carriers are totally unwilling to allow outside access to this information like GSM carriers do. Google built and maintains their own database of tower info, and that is what populates your rough location in Android. It is not aGPS data from Sprint's servers that is allowing that.
You want a hack? Well use the last known position, if it's historical then post a message "wtf turn on location services, if you want picture phone to work".
The app may not work but it won't crash as it has a location. More so it blames the user. lol
Post a little line to the location service enable semaphore, "who turned off the lights?"
You can get location assisted position from Wi-Max just like you can get it off Wi-Fi. As far as I know there is no app to disable Mobile Network Location on demand. If your having issues with it than users are going in and disabling it by hand through the settings. The problem probably is that 90% of the know it all bloggers advise to disable network position because they think it does something for battery life.
I'm also willing to bet good money that Google is handling the network location. Why else would they have a location server(supl.google.com). Only to let Nokia users use it?
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I've noticed that there are areas where the GPS doesn't work, even outside with no sky obstacles. One of them is on 113 st. between Broadway and Amsterdam avenue (NYC), right next to a building tagged "Cell Motion Laboratories." I've been there twice since I have EVO and the GPS is off like 10 buildings when I'm in the building next door. From outside, it just looks like any other Columbia University residence.
(Yes, my location settings were enabled and GPS was on).
ZIP 10027.
I just searched that lab, and it has nothing to do with cellphones, but with real cells (biological lab for kids, I think).
bedoig said:
You're correct that aGPS doesn't go through Google. It's presumably handled by the radio and Android is never aware of it at all.
Cell tower location/triangulation is different however. The OP is correct that it does go through Google, as the US CDMA carriers are totally unwilling to allow outside access to this information like GSM carriers do. Google built and maintains their own database of tower info, and that is what populates your rough location in Android. It is not aGPS data from Sprint's servers that is allowing that.
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What you are talking about for triangulation is software level functionality part of Google Maps and Google Maps only and yes it contacts their servers to try and guess where you are. Google does build out their own "database of tower info" just like they collect all sorts of other statistical information (you agree to this when you turn on location services), but part of the aGPS standard is that every cell phone tower, GSM or CDMA, transmits its coordinates to your handset.
What I'm talking about is all strictly in the hardware, but perhaps the word "triangulation" was the incorrect choice of word when talking about aGPS, however it is similar... The aGPS functionality in our phones is tightly integrated into the radio chip (Qualcomm RTR6500 CDMA2000) and this chip does not need to contact Google or Sprint to determine your rough location from a tower (turn off all internet access and you'll see what I mean). It can contact Sprints servers through the network (when it is able) to further plot your location based on the data transmitted to/from the aGPS server.
When you first use the EVO, there is a screen that asks if you want to share anonymous location data. That setting is also tied to network-based location services. That is, if you disable anonymous location sharing, it also disables NBLS entirely. You can thank either Google or HTC (not sure which) for their greed on that one.
I just checked and mine was set to off. not sure what sets it to that as I never touch that setting.
Just adding my 2 cents.
Samsung just wrote that apparently the use wireless networks, which is the option above use gps satellites must be selected to get proper locks.
I was skeptical because i just assumed that when I went exploring I selected it, but it actually wasn't.
Put it on, and agreed to the disclaimer and then right away the maps got my location and the live wallpaper map got my location.
you'll get an email saying google knows where you are and yeah its pretty ****ty that you have to do this, but it does work. at least for me.
not a real fix, I've had that on forever and still dont get a proper lock
Confirming that this does seem to work. It might merit mentioning that I've also messed around with my GPS settings quite a bit as well.
Regardless, I got a lock within two seconds after opening Google Maps. Cheers!
-deuX`
The phone used networks to locate you. Not GPS.
PuffinNugz said:
The phone used networks to locate you. Not GPS.
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Oh, good to know. Thanks for the info!
-deuX`
This is to assist in the GPS lock. This is not a fix.
True it isn't a real fix, hence the "quick" fix in the title.
it's just another way to help maps get a lock.
obviously this won't help in no service zones but if you're using the data anyways might as well use it to help.
plus it unlocks all the fun location based services, and that maps live wallpaper is pretty freakin sweet!
This will only give you the location of the nearby cell tower. Unless you live under the cell tower all the time, I don't think this is useful. It might be useful for things like check the nearby stores and attractions. But will not give you navigatable fixes and does not speed up your GPS lock. If you're using Google maps, try to zoom out, and you will notice a big circle. Your location is anywhere inside that circle.
That's Samsung tip is pure BS and Engadet should be ashamed to even believe in that BS.
I not only allowed the use of wireless networks for location, but also changing the GPS setting to MS Based to allow for simultaneous use of triangulation and assisted GPS... before this change I NEVER got a successful GPS lock...after I changed the settings I finally can get a GPS lock after about about 3 minutes with direct line of sight outdoors.
Sent from my SAMSUNG-SGH-I897 using XDA App
foxbat121 said:
This will only give you the location of the nearby cell tower.
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Not quite. its actually doing cell tower triangulation, using the signal of all nearby towers your phone sees. In the city, this can be pretty accurate and is rarely off by more than a couple blocks. To see the accuracy, turn off GPS and click 'locate me' in google maps. The blue circle around your location shows the margin of error. The more towers you are in range of, the more accurate the fix.
As far as helping GPS, all this location can really do today is help you grab the most appropriate gps almanac/ephemeris info - if youve got an internet connection. I suppose it could possibly also be used in conjunction with the gps error in some kind of a filter to improve accuracy, but as far as I know that is not being done.
I actually started getting quicker locks with just using the GPS and having the wireless networks unchecked
Just an update:
I changed the SUP/LCP setting to Auto-config and the Operation mode to MS Based. I tend to get a gps lock within a minute or two with it sitting on my dashboard. I also tried it with the"Use wireless networks" setting turned off and it worked the same.
Also, I did try out the MS Assisted SUP/LCP setting and I was able to get GPS signal while indoors, but it was less accurate all around.
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I'm not saying it's completely 100% accurate, but much in the same vein that an iPod Touch can get a location using just the wi-fi this is using much the same.
it uses whatever a-gps it can and then it helps with the cellular data. triangulation. it's useful and if it keeps getting me a signal then its all good
Is there a way to increase GPS accuracy of a phone for one specific location? Ie broadcasting your own GPS signal.
short answer - no
Long answer, incase you want reasoning....
our cells use two methods for give us our "GPS" service:
Cell Tower Positioning (not true GPS) & Global Positioning GEO-Sync Satellites (true GPS)
both methods are similar in that it takes the position of SEVERAL signals to triangulate your position.... the more signals it picks up, the more accurate your location.
While it is possible to provide a false reading, which is done to test and service GPS systems (this is done through a diagnostic port that feeds dummy raster data to the device) you CAN NOT BROADCAST a (potentially false) GPS signal.... doing such without an FCC license and licensed equipment is not only against the law, but can be very dangerous to anything else that might happen upon the signal... Crashing planes, cars, trains, and other GPS dependant systems come to mind...
For an interesting read regarding all this... see http://www.msnbc.msn.com/id/26992456/
As an FYI, There are Earth-Based stations that GPS can use to assist in positioning.... BUT it takes about 3 years to get the FCC approval, and about $15 million in equipment for a MODEST station.... if your still interested... I even know of a business that would be willing to do the setup-install ;-p
I continued searching, and even the false gps is still quite expensive (thousands).
There is some hope for the future, InvisiTrack, though I suspect there are people who would say they are close to a Time Masheen.
However then I stumbled on, gps repeaters. Not that I could find a price or legality (they are aimed at businesses and have no US distributer). This seems like the solution, but need FCC approval in the US. Canada might be fine.
*For links search google for the terms, being a new user sucks.
Sorry... wish there was a better answer, but with SO MANY governments and systems utilizing GPS Positioning... MANY of which are very dependant on the service.... it's easy to see why it's very regulated & protected.
Depending on your device, try a different Radio ROM... or maybe try pointing the software you're using to the specific COM & Baud of the GPS, instead of having the OS be the go-between... sometimes that will boost the performance.
For example... i've got the HD2, and from the HTC GPS tool I found that the GPS is on COM4 with a Baud of 57600. When I pointed Google Maps & Bing to the specific COM/Baud I saw an increase in the number of sats it picked up... and the location was more accurate.
Also... there are apps like QuickGPS which will periodicly download the GPS sat. locations.... allowing the device to pickup the sats quicker.
Ive started looking for a way that does not involve GPS, but using other frequencies to determine location.
One method seems to be placing bluetooth devices throughout the location and using those to determine a location. Currently looking into feasibility.