Comment 17 for bug 1421623

Revision history for this message
Ondrej Kubik (ondrak) wrote : Re: [Bug 1421623] Re: Welcome wizard claims GPS is less accurate than wifi based location

Option for only wifi + cellular is not really needed for user to chose from.
It is still used by the device, when application does not require precise
location, in order to preserve battery, but this is not to be controlled by
user. In my option no need to have any option like this here.

Still your statement is wrong, you are not referring to accuracy in your
examples but to actual availability, yes when you cannot get GPS lock, then
your wifi will get "better" location, in comparison to no location at all.
Yes wifi is more "accurate" while GPS is acquiring lock. But this is not
accuracy, but speed. It is like saying motorbike is faster than car,
because it can accelerate faster from still, even though car can actually
develop greater top speed.

But do you have case, where GPS is accessible and your option GPS+wifi is
more accurate in comparison? to back up "less accurate" statement?

So adjusting my example with data connections to your logic:
- 4G only (slower)
- 2G/3G/4G

This is obviously wrong, yet by your logic, it is correct. Combined
4G/3G/2G will never be faster than option 4G only, yet there will be cases
without 4G coverage when it will be "faster" compare to no 4G signal. By
your logic 4G is then slower.

On Tue, Sep 1, 2015 at 10:42 AM, Matthew Paul Thomas <email address hidden>
wrote:

> "From all location providers available, GPS is most accurate one,
> unfortunately also most power hungry and slowest to gain lock. This is
> reason we use all other providers to get faster, though less accurate,
> coarse location using combination os visible wifi access point and
> cellular cells."
>
> As I have said three times now, just Wi-Fi + cellular network info is
> not one of the options. It is in Android, and both Rex and I have
> mentioned here the possibility of adding it to Ubuntu -- but right now,
> it is not one of the options. If it was, you would be correct: you could
> save power by not using GPS. But the choice is between GPS only, or GPS
> + Wi-Fi + cellular network info. Since both of them use GPS, neither of
> them save power by not using GPS. And after seven months, you have still
> not given a single example of any moment where GPS only could possibly
> be more accurate than GPS + Wi-Fi + cellular network info, while I've
> given multiple examples where the opposite is true.
>
> Your GPRS analogy fails for the same reason: "GPRS only" is not one of
> the available options, just like "Wi-Fi and cellular networks only" is
> not one of the available options.
>
> The reason we provide multiple options, as explained in the UI, is
> nothing to do with power use. It is simply that the HERE option requires
> you to accept HERE's terms and conditions, while the GPS-only option
> does not. If we didn't care about providing location detection for
> people who don't want to accept the terms and conditions, we could just
> use HERE as the only option, make location detection an on/off toggle
> (like in iOS), and not need any further settings.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1421623
>
> Title:
> Welcome wizard claims GPS is less accurate than wifi based location
>
> Status in Canonical System Image:
> New
> Status in Ubuntu UX:
> Invalid
> Status in ubuntu-system-settings package in Ubuntu:
> Invalid
> Status in unity8 package in Ubuntu:
> Incomplete
>
> Bug description:
> First boot welcome wizard in location sections claims GPS is less
> accurate than network based location service from HERE.
> While this can be theoretically true in some insane corner case, in
> normal life GPS is far more accurate.
>
> To help form correct text here are main differences.
>
> GPS - more accurate, but slow to acquire fix, does not work indoors,
> drains battery more, no need for internet connection, does not send
> any data out.
>
> Network based location - almost instant to get coarse location, works
> indoors, accuracy depends on network coverage in the area, more power
> efficient, requires internet connection. To get location data about
> visible GSM network and wifi networks needs to be send to 3rd party
> server.
>
> tested on krillin vivid-proposed r107
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/canonical-devices-system-image/+bug/1421623/+subscriptions
>