Location Services - Possible on TTFF Only?

Hi everyone,

This is my first post here.

Can Sailfish OS on Xperia XA2 and its variants work only on TTFF or does it need A-GPS? I have seen some issues on this forum regarding problems with GPS fix after the removal of MLS (Mozilla Location Services) but I have been using another Linux phone with pure TTFF for more than a year and would like to know if SFOS on XA2 and its variants can purely function the same.


Look at https://forum.sailfishos.org/t/hardware-xa2-gps-trial-to-fix-it-for-debuging/10133

I do not unterstand your question entirely but TTFF is Time To First Fix.

SFOS can position your device on GPS data without any additional services. This might take a little longer and has all limitations that GPS has but it worked for me on the XA2 and works on the 10 III. I have navigated through the better part of Europe that way.

On the XA2 the antennas degrade in some cases and there are hardware fixes around in this forum.

When my XA2 became unreliable, I bought a 10 III, which is far better for GPS use.
My XA2 was downgraded to my idiot phone, a device for things I would not do with my normal phone. It runs on Lineage and with Android navigation is ok again.

So: If your XA2 has still good antennas or you are willing to fix them in case of degradation, the device is a good choice.
A 10 III though is far better.

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I don’t know your project but note tat the XA2 GPS is not working in Flight Mode, even if it needs no data from the internet to find it’s GPS position.
I believe this is due to the fact that GPS and MODEM are into the same chip.

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Wow! Thanks for all the replies. It feels like this community is really active.

Yes, TTFF (time to first fix), when presented in the navigation industry specs as it is, means the device doesn’t use any other means to get a GPS fix other than the GPS satellites. This is common in older standalone GPS devices in the 2000s. Nowadays A-GPS is common but that’s not what we want because of privacy issues. I don’t really mind waiting 15 mins for the first fix because the next ones will be much quicker.

For reference, I am using another Linux phone that only has TTFF and I like it that way. I have been navigating offline with this phone and it’s all good so far.

That’s not good to hear. Anyway, I just bought an XA2+ and it’s my first venture into Sailfish OS, although I experienced the MeeGo when I had a beautiful masterpiece, the Nokia N9.

I may consider this once I warmed-down with SFOS.

You may have a point. I will look into this.

I just don’t want to use location services with A-GPS, that’s all. I don’t want to connect to any servers with my device.

I will look into this. Cheers.

Your use of TTFF as if it was a mode or technology is quite incomprehensible.
It is, as you also say, (only) a measure of performance. And although said measure might have criteria, that doesn’t make the terminology interchangeable.

You also seem to have missed that MLS is now made available as offline packages, which should have no real privacy concerns.

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Apologies for the confusion. It might be a colloquial word for us in fieldwork because we didn’t have A-GPS back then and when A-GPS came, we still refer to satellites-only as TTFF.

Well I have definitely not read about that. As I have said, I am so new to the OS and haven’t used A-GPS for a while as I don’t like the companies connecting to a certain server from the big G. I will look into this. Is offline MLS similar to the OSM Scout Server?

Take a look at Jolla Store. App is called Positioning - XX . They are different for different parts of the world.

But just to answer your first question: Location services can be set to local GPS device only, no assistance, no internet access, no gps cell or wifi analyses for location services.

For comfort reasons additional services were widely used on the XA2 I suppose. But I got along well without them.

If it comes to term “offline” that yes, MLS and OSM Scout are similiar. MLS is a local database of mobile phone cell id’s that is used by phone’s location service for rough TTFF. You can recognize it by 9km accuracy.

Thanks. I will look into this.

Got it. I just checked the newly-acquired phone and positioning is rather quick for GPS-Only. I mean, it’s way quicker than expected, based on what I have been reading here. Anyway, it can probably be just a revision but I am not sure.

Copy that. I will definitely read into this.