GPS without cell signal?

[TinCanFury]

I can't get any of the compass/gps logger apps to work with GPS when I have no cell signal or the cell antenna is off. is there a setting somewhere I have misconfigured or is the hardware on the 9650 just not capable of using the GPS when there is no cell signal?

[Fubaz]

im pretty sure the gps chipset uses the cell radio data to determine where you are. as the phone does not have the maps and co ords of the world onboard

[TinCanFury]

yea, but I'm just trying to use the GPS with a compass or logger app, neither of which need cell service, they just read the GPS positioning data, but the GPS turns off when either I turn off the Mobile Network or I lose cell signal. I'm hoping this is just a silly setting somewhere that I've missed and not a design flaw.

[Culex316]

Originally Posted by Fubaz

im pretty sure the gps chipset uses the cell radio data to determine where you are. as the phone does not have the maps and co ords of the world onboard

The GPS chipset uses the cellular connection for aGPS to get a quicker lock onto the satellites, otherwise it can function just perfectly autonomously and pick up the satellite signals on its own (although this could take up to 10-30 minutes)

[jbeachy]

+1 Culex. I have tested this numerous times by turning off cell service. GPS works just fine on my Verizon 9650/6.0.0.524 without cell service. I haven't seen the 10-20 minute wait Culex refers to but there is indeed a setting in the Location settings to Enable Location Aiding by using network information. So it seems logical it might take longer without that.

Posted from my BlackBerry using BerryBlab

[Culex316]

Originally Posted by jbeachy

+1 Culex. I have tested this numerous times by turning off cell service. GPS works just fine on my Verizon 9650/6.0.0.524 without cell service. I haven't seen the 10-20 minute wait Culex refers to but there is indeed a setting in the Location settings to Enable Location Aiding by using network information. So it seems logical it might take longer without that.

Posted from my BlackBerry using BerryBlab

well if you have location aiding enabled then it won't even take 30 seconds to get a lock...but in autonomous mode (i.e. without any location aiding and if a certain amount of time has passed since the last lock, or if you move to a completely different geographical area), the GPS receiver has to first download the almanac/ephemeris information that tells it where the satellites are and then lock onto the satellites themselves.

[TinCanFury]

the "almanac/ephemeris information" can't be that much that the phone can't just have it stored.

anyway, I think I figured out my mistake trying this before. Location Aiding indeed has to be disabled, and apparently it gets reset to "enabled" sometimes, so if you want to use it without cellular connection you have to make sure it's disabled each time. The GPS software also needs to have it's GPS mode set to not override this setting, as it looks like the software can override the Location Aiding option on it's own.