Does "my location" work for anyone on the new google maps

[Malatesta]

Originally Posted by TC1

As previously discussed in other threads, it isn't going to work. Sprint has locked down the aGPS API (which is what this app needs) on WM6 phones.

Also, Google ripped off the idea for this app from the author of mGMAPS, which is an awesome real-time GPS app that works off of the aGPS API... I was able to unlock my wife's Sprint LG Fusic and run it on there. Free GPS and location based services!

I was under the distinct impression that this is cellular triangulation, which is very different than aGPS (it is far less accurate).

This is the same issue with Windows Live Search and Sprint: triangulation, not aGPS.

It works, evidently, on a Treo 750 with WM6. Some are suggesting that Google is "rolling it out" per device and since it's still beta, our devices have not been implemented yet. Have to wait and see.

Although from the Cnet article;

The new feature will be available on most smart phones, including the BlackBerry, new Nokia Symbian devices, many Windows Mobile devices (except the Motorola Q, Samsung Blackjack, and Palm Treo 700W).

[TC1]

Originally Posted by Malatesta

I was under the distinct impression that this is cellular triangulation, which is very different than aGPS (it is far less accurate).

This is the same issue with Windows Live Search and Sprint: triangulation, not aGPS.

Malatesta, aGPS is cellular triangulation... I'll do a quick explanation here (I'm sure I've typed this a million places elsewhere, lol):

aGPS stands for assisted GPS... aGPS in many ways is actually better than stand alone GPS because the device (cell phone) doesn't have to find/receive the GPS signal from the over-head satellites. It takes additional power to receive the sat signals as opposed to just receiving the cellular network signal, thus cutting into your phone's battery life.

How does aGPS work? What it does is let the carrier's network do the computational intensive triangulation measurements (which also saves phone power).

How does this happen? Every cell tower has it's own stand-alone GPS receiver, that way every cell tower knows its own location, this will become important in a second. On the carrier's network there are computers known as Assistance Servers, these are the devices that do the actual triangulation computations. Emergency response organizations (ie, 911) have access to these servers, as do the phones themselves (as long as they are unlocked).

The details: either the cell phone or emergency services can start a query with an assistance server, the assistance server will then go out on the network and query all the cellular towers in your general area with a request such as "Hey, do any of you towers have a cell signal level for cell phone #123456?" If a tower detects the cell phone's signal it'll respond with the tower's (precise) lattitude and longitude location and the cell phone signal level. The assistance server will collect all the cell phone signal levels relative to each tower's location and then do the triangulation computation. It'll return the computed lat and long measurement back to the original requester (the cell phone or the 911 network computers).

By accessing the aGPS API for the chip in the phone, that's how a program like mGMAPS makes a phone like my wife's LG Fusic GPS capable... even though it has no stand-alone GPS capability. This is also how carrier's LBS (location based services) work on phones that aren't full blown PDAs with stand-alone GPS, etc. That's why Sprint wanted to shutdown the author of mGMAPS... he was basically giving folks for free capabilities that the carriers normally charge extra $$$ for.

Hope this explanation was clear and helpful

-TC

[Kasracer]

aGPS does some cellular triangulation to get a rough idea where someone is and to help the GPS device using aGPS to lock onto a GPS satellite.

This does not mean that the new Google feature is using aGPS in a traditional sense. Typically aGPS is only used when a GPS device can use it (it is, after all, meant to assist a GPS device and not be a stand alone device or service).

Since Google's and Microsft's Live services both have this feature, I very much doubt that they are using Sprint's (or any other carrier's) Assistance Server mainly due to the fact that some of the services, like Microsoft's, never required any updates on the device itself (as far as I know; I never tried it). Besides, if an API was either non existant or locked out that Google was using, I'd imagine you would get an error message or Google would handle the error properly and tell you it's not supported.

Of course I could be mistaken as to how Google is implementing this feature but you very rarely see any aGPS used without a real GPS unit as it was designed to help the GPS unit lock onto a satelite (by definition, you may never see aGPS used as a stand alone function but see something very similar that uses triangulation).

[TC1]

Kasracer , I have to respectfully disagree with your explanation. aGPS stands for assisted GPS... it doesn't mean that it's meant to assist a stand-alone GPS device, ie, one that derives all it's information primarily from the overhead satellites. A stand-alone GPS device doesn't need help... think about it. The OEM GPS system in my car never needs help locating a satellite. The stand-alone GPS receivers that you buy for your car (Tom-Tom) never need assistance. Even the small key chain models available don't need assistance. Either there is a signal or there is not.

Now, if a device is both GPS and aGPS capable, that just means if it can't see the sats, then it will use the cellular network to get its lat and long info. One has nothing to do with the other. That's why a flip phone with no standalone GPS capabilites can get location based services via aGPS. GPS and aGPS on a phone are distinct capabilities that have nothing to do with each other, other than the fact that a device may be capable of both and use each one as needed.

[Kasracer]

Originally Posted by TC1

Kasracer , I have to respectfully disagree with your explanation. aGPS stands for assisted GPS... it doesn't mean that it's meant to assist a stand-alone GPS device

What? do you know the definition of assisted? it's meant to assist other GPS chipsets/devices.... your integrated GPS as well as an external GPS tool can both take advantage of aGPS (though, of course, this always depends on the implementation).

Originally Posted by TC1

Now, if a device is both GPS and aGPS capable, that just means if it can't see the sats, then it will use the cellular network to get its lat and long info. One has nothing to do with the other. That's why a flip phone with no standalone GPS capabilites can get location based services via aGPS. GPS and aGPS on a phone are distinct capabilities that have nothing to do with each other, other than the fact that a device may be capable of both and use each one as needed.

This isn't true on most phones. aGPS assists GPS to find a satelite to lock onto. it doesn't just magically replace it if it can't connect with a "rough" location.

Look it up in Wikipedia

[TC1]

Originally Posted by Kasracer

What? do you know the definition of assisted? it's meant to assist other GPS chipsets/devices.... your integrated GPS as well as an external GPS tool can both take advantage of aGPS (though, of course, this always depends on the implementation).
This isn't true on most phones. aGPS assists GPS to find a satelite to lock onto. it doesn't just magically replace it if it can't connect with a "rough" location.

Look it up in Wikipedia

Again, I'm going to have to disagree. All because something is on Wikipedia doesn't mean it's accurate. I'm a BSEE with over 25 years of digital chip, computer, software, and network design. I've talked to developers trying to crack the Sprint GPS issues.

You might get a better understanding of how aGPS works if you look at the mGMAPS web site. Look how the author there wrote the app, and for Sprint phones he specifically says "The QJAE GPS API (Sprint) was updated to prefer assisted-GPS over standalone GPS. This sacrifices accuracy for quicker fixes and more stable GPS positioning." Meaning that, yea, the application magically (as you put it) switches over to the aGPS system to get the lat and long coordinates if the stand-alone GPS receiver can't supply them.

Let's just leave it at we agree to disagree.

[crowssong]

Originally Posted by TC1

Again, I'm going to have to disagree. All because something is on Wikipedia doesn't mean it's accurate. I'm a BSEE with over 25 years of digital chip, computer, software, and network design. I've talked to developers trying to crack the Sprint GPS issues.

You might get a better understanding of how aGPS works if you look at the mGMAPS web site. Look how the author there wrote the app, and for Sprint phones he specifically says "The QJAE GPS API (Sprint) was updated to prefer assisted-GPS over standalone GPS. This sacrifices accuracy for quicker fixes and more stable GPS positioning." Meaning that, yea, the application magically (as you put it) switches over to the aGPS system to get the lat and long coordinates if the stand-alone GPS receiver can't supply them.

Let's just leave it at we agree to disagree.

And just because one self-proclaimed expert says something doesn't mean he's accurate either.

aGPS may use triangulation as part of its data sources, but that doesn't mean that all triangulation (or more accurately trilateration) methods = aGPS. What Google is using for this system is not requiring any use of any aGPS chipset. The program only needs the phone to pass on some tower information. Which means that it isn't requiring any intervention on the part of the assistance server for it to function. Which would be why Google is able to offer this service without getting permission from Sprint, Verizon, AT&T, etc.

If you don't trust Wikipedia, then maybe another article might educate you better.

http://www.gpsworld.com/gpsworld/art...l.jsp?id=12287

[Malatesta]

Originally Posted by TC1

Malatesta, aGPS is cellular triangulation... I'll do a quick explanation here (I'm sure I've typed this a million places elsewhere, lol):

aGPS stands for assisted GPS... aGPS in many ways is actually better than stand alone GPS because the device (cell phone)...

I know all about aGPS as I've written on it extensively at WMExperts.

But Google Maps "My Location" is based on the device Cell ID, which on some devices is hard to get (e.g. all Palm OS devices--only one developer has ever been able access it, GreenHex--hence there are 0 Palm OS devices that work with this) and based on signal strength.

Seeing as it is accurate to "within three miles of their actual location", these are not the numbers of aGPS, which is actually quite accurate. This is old school cell triangulation.
http://www.al911.org/wireless/triang...n_location.htm

The assertion that this is aGPS is flat out wrong.

--Mal