Anyone used the GPS in Europe yet?

[shaggylive]

Originally Posted by DogPack6

The behavior of the external GPS and internal GPS using the native redirector for internal and GPS gate for external is different.

With the internal GPS, sats are read and data is received, but after a while it appears the GPS resets and starts reacquiring GPS data, while the external GPS seems to build on the signal of sats it is currently communicating with. In addition, the phone itself will periodically soft reset while acquiring data through the internal GPS.

this supports the theory that the internal gps is choked by ram/cpu/driver... and/or it is truly only a supplement to agps.

I did have some new thoughts though.
1. have you try'd navizon?
2. I wonder if you could use navizon/gpsgate/gps2blue or a something running on a laptop to emulate a smartmode server. such as gpsgate's tcp output.
kind of a jumpstart

[jpeepers]

Originally Posted by shaggylive

yes. the ideal test would be inline with an external antenna, to make sure ANY activity over the cell radio is detected.

OK, I'll test it today and see what I come up with.

GPS receive Frequency is at 1575.42 MHz (L1)

[timewaster]

Originally Posted by DogPack6

Well I've given up with the GPS in Germany...never once received a lock. As a backup, I used a BT GPS. With the NO2CHeM 6.1 ROM 5060, I was unable to set the GPS hardware port in the native redirector to anything but (none), so I was forced to use GPSGate, which worked like a charm. I've been quite busy with work, but I wish I had more time to test the GPS lock issue with the stock ROM.

For the internal GPS issue, the GPS is returning sat data, it just won't lock.

The behaviour of the external GPS and internal GPS using the native redirector for internal and GPS gate for external is different.

With the internal GPS, sats are read and data is recieved, but after a while it appears the GPS resets and starts reacquiring GPS data, while the external GPS seems to build on the signal of sats it is currently communicating with. In addition, the phone itself will periodically soft reset while acquiring data through the internal GPS.

I used the GPSviewier trying cold reset to completely reset the internal GPS and there seemed to be no improvement.

this is exactly the same results i get when i put it in flight mode and do a soft reboot afterwards.
i cannot aquire a gps lock in nyc.

[jpeepers]

Originally Posted by jpeepers

OK, I'll test it today and see what I come up with.

OK, I just did a test using a spectrum analyzer with the phone in flight mode. I tried several GPS applications and I can confirm it does NOT contact the tower using the cell network. There was no signal activity at the cellular frequency band.
That doesn't mean it's not receiving signals from the tower but it is definitely not transmitting to the tower.

I confirmed my test setup by putting the phone back in "phone" mode and I can monitor the transmitions to the tower very clearly.

Hope this helps?

[bedoig]

Can anyone think of a way to test wether it is receiving data? I don't see any way to easily eliminate the possibility that it is receiving location data. Maybe there are some internal logging routines or something, but that is well beyond my meager know how.

[jpeepers]

Originally Posted by bedoig

Can anyone think of a way to test wether it is receiving data? I don't see any way to easily eliminate the possibility that it is receiving location data. Maybe there are some internal logging routines or something, but that is well beyond my meager know how.

I think you may be SOL with that? Hardware wise there is no way I can tell if it's receiving or not. If I could pull the phone apart and had a schematic for it I could probably tell you but but I don't think that's going to happen

Like you said there may be some way to do it in software but I'm a hardware guy so that's out of my league.

Edit: Wonder if some one could write a routine (or already have one) that would poll for signal strength? The signal strength meter goes away from the home screen when in flight mode but the receiver still may be active in the background?

Just a Thought.

[bedoig]

After a little more reading, I found that Qualcomm's gpsOne system is actually used all over the place, not just in cell phones. They are even used in dedicated navigation devices, which I can almost guarantee don't require a cell connection to function. The chipsets vary, but from what I can tell the Qualcomm chipsets used in PNDs are quite similar to the MSM7xxx series. The main differences being the lack of support for hardware graphics accelaration, 8+ megapixel cameras, etc. Stuff you wouldn't need in a navigation device (or any other less demanding platform where that chipset would be used). The QST1100 that is used in several PNDs does have cell connectivity and aGPS, but how would customers feel if they couldn't use their navigation device when they really needed it (ie. remote locations) due to lack of cell coverage. It's GPS related features list reads virtually identically to that of the MSM7500.

I think the real issue is still just the difficulty in establishing a lock in a significantly different location. Is this normal, or are the users having difficulty here just a fluke? Will programs like Navizon, WiFifofum, etc help in establishing a new fix?

[jpeepers]

Originally Posted by bedoig

I think the real issue is still just the difficulty in establishing a lock in a significantly different location. Is this normal, or are the users having difficulty here just a fluke? Will programs like Navizon, WiFifofum, etc help in establishing a new fix?

I know in a dedicated GPS receiver it can take 20 + minutes to acquire when moving to a new location, especially if it is far away from it's last known position. If the unit has moved a significant distance from it's last location it must down load a new almanac which takes additional time.
Of course there are many factors involved, accuracy of the unit, signal strength etc.

[jpeepers]

This is info you may already know but I thought I would post it.

When your within your cellular reception area you are able to receive AGPS from the towers which will already have "almanac" type data embedded in it speeding up the GPS acquisition times. Outside of that you are relying completely on the GPS receiver.
One of my thoughts is that the onboard GPS receiver is extremely weak (at best) there for its relying on the AGPS to do the majority of the work. If AGPS is not present you may have a hell of a time getting a location fix.

. AGPS uses a mobile network to reduce the initialization time that a normal GPS receiver needs to receive navigation data. In AGPS, information about satellite orbits and errors previously measured by a base station is provided to the terminal through a communication means. The GPS chipset or module mounted in the terminal determines the location of the terminal in a short time using the data received from the base station and the calculated pseudo distance from the GPS satellites.

Since satellite orbit information and correction information are transmitted from a position determination entity ("PDE"), installed in the base station, to a mobile station, AGPS ensures faster response times than stand-alone GPS and can track GPS signals even in weak signal conditions such as downtown areas or indoors.

When location or time information is not provided, a mobile terminal has to track search spaces with frequencies and codes of all GPS satellites to acquire GPS signals and calculate its location. AGPS combines rough location and time information from the mobile network with satellite orbit information to predict the GPS satellites currently in view with the Doppler shifts for the visible satellites to reduce the number of searchable satellites and speed up the response. Knowledge of currently operating satellites reduces the number of satellites to search for and reduces response times.

[bedoig]

Originally Posted by jpeepers

One of my thoughts is that the onboard GPS receiver is extremely weak (at best) there for its relying on the AGPS to do the majority of the work. If AGPS is not present you may have a hell of a time getting a location fix.

That's kinda what I was thinking. Although I would tend to think that it is more an issue of a crappy antenna than a weak receiver. Probably why you see external GPS antenna jacks on some GPS enabled smart phones.

As you said earlier, the device sees satellites but appears to eventually reset before getting a location fix. Maybe there is a timeout setting that can be adjusted.