Re: Modem supporting location information?

[Dan Williams <dcbw redhat com>]

On Thu, 2012-12-06 at 12:46 +0100, Bastien Nocera wrote:
> On Fri, 2012-11-30 at 17:55 +0100, Aleksander Morgado wrote:
> > On 11/30/2012 05:48 PM, Bastien Nocera wrote:
> > > I'm interested in getting a 3G modem that would support A-GPS. I have a
> > > (possibly simlocked) option modem:
> > > 0af0:6971 Option Globetrotter HSDPA Modem
> > > 
> > > Which tells me that it doesn't support Location services. Does it not
> > > support it, or is it not implemented?
> > > 
> > 
> > That one should be supported in ModemManager git master, see:
> > http://sigquit.wordpress.com/2012/03/29/enabling-gps-location-in-modemmanager/
> > 
> > But not A-GPS; just plain GPS for now.
> 
> What would be needed for A-GPS support?

We need to come up with a good interface here; there's a lot more
parameters to send to the device for A-GPS, and it's slightly different
between 3GPP and CDMA.  We need at least a SUPL server IP/port or URL,
possibly a SUPL-specific APN/authtype/user/pass, and for Qualcomm maybe
three gpsXTRA download server URLs and whether auto-download is enabled
for gpsXTRA.  We'll also need a command to clear any cached GPS assist
data.

For example, SUPL configuration may require:

• Set specific security parameters
• Store SUPL certificate in modem
• Set specific GPS APN
• Set SUPL server’s address and port

> > > I also have a Huawei E585 modem, which doesn't support switching to USB
> > > mode when plugged in, but apparently support A-GPS. If we can make this
> > > work, it would save me buying a new dongle.
> > > 
> > > Otherwise, I'm in the market for a 3G modem that supports those. Cheaper
> > > is better. Anything on eBay or Amazon that people would recommend?
> > 
> > The other modems which (currently) support GPS location services in
> > ModemManager are all those QMI-based modems implementing the PDS
> > service. E.g. my old Gobi 2k modem built-in my Thinkpad laptop does it,
> > and many newer modems (e.g. Pantech UML290) also do it IIRC.
> 
> How about the Dell 5520 cards? I have one of those stuffed in an ancient
> Dell machine.

I've got the ExpressCard version of that one (Novatel EU870) but I don't
think that has easily-available GPS capability.  I'm not aware of custom
Novatel commands for GPS, and we haven't reverse engineered any
QCDM/DIAG GPS stuff yet.  So no.

> Any ideas also on turning the Huawei modem into a USB one?

The E585 wifi hotspot?  I recall that one is actually QMI-based, it's
android on the inside, so we may have some hope there.

Dan