GPS stopped working

Bug Reports
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#504

A SUPL request contains your IMSI as session id, a rough location estimate (i.e. your last position), the cell id of your current cellular connection, and of cause some IP address. The IP is not that interesting since it is most likely shared and temporary as your provider uses NAT at least for IPv4, but the IMSI is unique.

Not really. At the monent I’m using supl-proxy against a chinese SUPL server. This proxy replaces the IMSI in requests before forwarding to the real server and reverts the change on the way back. The SUPL provider only sees the spoofed IMSI (something starting with 26201, i.e. German Telekom).

You only need a host with a reasonably new Python3 that is reachable from the internet and change gps.cont to point to it. You could of cause also use eierkopp.ddnss.org:7275, but that means not the Chinese spying on you but me. :stuck_out_tongue:

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#505

Just make a promise about privacy and I’ll trust you. We all believe promises only, about e.g. some OSes, after all :yum:

But then, the SUPL provider knows the site from where the SUPL request is made, and it’s yours. Isn’t it worse?

I anyway could host something like that as I have a domain name with an unused website. But is it complicated to setup?

#506

I’m behind a DSL line with changing IP addresses but just added SOCKS support anyway. Hence it’s possible to have TOR in the middle without any networking hacks.

If you have a Debian derived distribution, just build the package, install, configure /etc/default/supl-proxy and run the service. For other systems its probably a tad harder but also not much more than running a Python script.

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#507

Tried those settings (with XA2, single sim) - fix in 271 sec. High precision. Inside, phone 30 cm from a huge window (accually two windows 2,5 meter high x 1,2 meter wide) Will try again in few days as this seems to work randomly for me. Before the patch it fix’ed sometimes in 3-10 minutes and sometimes after 30-40+ minutes I’ve gave up.

#508

Im still having issues with getting a fix indoors, it really doest matter if Im close to the window and how big it is :slight_smile:

Outdoors it seems to be a different matter. Fix comes within few seconds and works almost flawlessly. I tested it with PureMaps Google maps (Car) and with MeeRun (While running of course). AccuracyI is very good and collected data (throughout the run for example) seems correct as I have many different .gpx files to compare

Still, you may have let’s say hardware issue there. As Xa2’s seems to like falling apart. There are many connectors and antenas. Recently (Before applying the patch) i had mine stripped to pieces and cleaned very thoroughly. Than i glued it back to one unit and it seems to hold on. As i mentioned Im running a lot and it doesnt hurt my phone anymore. You should consider this as well, I mean cleaning it inside and gluing carefully as it seems that factory glue looses it strenght over time.

#509

Thanks for reporting.
About disassembling, we must be very careful to the 4 small contact on the top.
They are very fragile. (more in the GPS HW tread )

I’d say that having a bad GPS reception inside is normal.
Goopple are kind of cheating with BT and Wifi used to position, compared to pure GPS use.

#510

Yep, this mirrors my current experience even with suplpatcher on X10II.

Indoors just isn’t getting a fix.

#511

Well… Do you guys really often don’t know where you are when you are indoors? :stuck_out_tongue_winking_eye:
It used to happen to me late at parties when I was young but didn’t anyway see clear enough to read a GPS which didn’t exist at this time.

More seriously:
Do one of you remember how did pure GPS only devices work inside? Was it working at all?

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#512

GPS receivers are not supposed to work inside (or in any condition where the sky is not visible). Any fixes got inside are random and should not be relied upon.

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#513

Well of course they are not. Anyway sometimes it’s useful to have fix indoors, for example if you are checking out a new app that need fix to be established to show all the features. For weather app or something.

I mean fix indoors its not something you rely on, but can be useful for different applications :slight_smile:

#514

Oh, I see, ok.
Was just kidding, imagining people lost in their own places… :grinning:

2 Likes
#515

I think people who had android phone kind of miss it. Its nice when pizza delivery app knows where you are especially when you are spending your free time someplace sunny and you dont remember street name :stuck_out_tongue:

1 Like
#516

I was referring to AGPS.

Basically, anything less than what Android can do for years already, is just weak.

#517

More seriously:
Do one of you remember how did pure GPS only devices work inside? Was it working at all?

As far as I’m aware, it’s almost never that GPS works indoors (ie you’d have to have an unusually thin roof, walls, and few obstructions outside of the building). Instead it’s AGPS that gets the result, which uses a combination of what-ever-works-at-the-time, including:

  • GPS.
  • Which cell towers are visible, and how strong the signals are relative to each other.
  • Which wifi hotspots are visible, and how strong the signals are relative to each other.
#518

I guess any better solutions one can provide are welcomed.

[OT]
SFos IS weak. Like lots of important initiatives/people in history.
But personally, I am thankful for it to exist.
[/OT]

4 Likes
#519

I don’t think it’s quite that bad. I’ve had several locks indoors with bog-standard SF GPS support but it does need to be top floor/bungalow and probably depends on the roof material.
I also got window ledge locks everywhere.

Is the bottom ‘bracket’ also GPS or a different aerial?

I think it’s worth summarising the last month’s info in this thread and putting in a wiki or something.

#520

This said, I agree with you that this GPS problem is a big important bug that should be fixed. Even on “old” devices like XA2 if we want to help slowing down waste and consumption.
@flypig told us people at Jolla are working on it. Let’s hope they find the bug soon!

Even the whole thread. I tried to summarize once for myself but it is long.
I believe you could begin a new thread and ask the mods to turn it into a wiki.

#521

I think what we have now with google is partial AGPS. A GPS supperted by cell tower information, but not by wifi hotspots (?)
If so, why? This ggl fix should bring android-like gps expirience so why it’s relying on GPS and Cell Towers only?

#522

It’s because of the SUPL specs that allows only sending of cell tower IDs to get the ephemeris data for your approx. position based on cell tower location.

A speedup here was MLS which injected a current location based on wifi networks which is more accurate than triangulated cell tower signals. In that case SUPL ephemeris and more accurate current location gives another additional speedup for time to first fix.

However in my experience if you are outside and use SUPL a fix will be within a few seconds so using additional wifi scans is not needed (and currently supported by SFOS).

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#523

After upgrading to 4.4, the gps seems utterly dead. The suplpatch solution that I used to use with success no longer seems to work (one has to re-edit gps.conf as it was overwritten on upgrade). Using suplpatch --enable to go back to the previous mode and then use sonyericsson.com as provider and 7275 as port and the user settings under location also doesn’t work. There is a number of satellites but no activitiy in gpsinfo - e.g. under “Last update” there is just a dash.
Anyone with the same problem?

1 Like