I just installed the Positioning-Southern-Europe package. But now I have a question due to my poor experience with SFOS, and my lack of knowledge about mobile towers:
When I installed I read: “Positioning using the data does not require network access. Positioning data contains mobile phone information for the region.”
If I drive offline only with GPS activated (with my SIM card off, as usual), is it then the GPS of my smartphone that informs the mobile towers of my position?
Nothing informs towers of your position^[1]. Towers “know” their position, and your SIM, when active, registers with (one or multiple) those towers.
GPS only deals with satellite signals. But in order to be accurate quickly, GPS needs to know approximately where you are so it can use the satellite data effectively.
Mozilla Location Service (MLS) data comes into play here. It is a collection of information which towers are located at which (GPS) position.
When your SIM/modem registers with a tower, the tower sends a certain ID (cell number). By looking up this cell ID in the MLS database, the Location Service on the phone can use this information to have a rough idea of where you are, so GPS can get a better fix.
[1] about positionong your phone through the SIM: network providers do record which SIM logged into which tower at which time. They need to otherwise they couldn’t route calls and data traffic to you.
But a single tower can only estimate your location by the signal strength of the connection between it and the phone.
Through a process called triangulation, which combines the signal strength picked up by multiple towers, the position of your phone/SIM card can be pinpointed more or less accurately by the network providers.
Whether network providers do that, log it, keep those logs, share those logs, and admit to any of it is another topic.
So that assumes that I must necessarily have my SIM ON from now on to drive more precisely.
However, I also gathered from your detailed explanation that the data expenditure is minimal if I have the maps downloaded to OSMScout Server (I’m concerned about the data expenditure, even if it’s just for triangulation).
But then, I guess I also have to change the Pure Maps profile from my current “offline” to “online” (or “mixed”).
To benefit from this service you must only turn on the SIM card and receive at least one tower. You can switch off data communication (mobile data), so you do not consume your data volume of your SIM.
The maps and the MLS data must be stored on the phone before navigating.
This just cleared up all my doubts and concerns about MLS packages. Thank you for your patience on questions that I suppose may have seemed too obvious to you.
Thanks @atlochowski, @nephros, @Seven.of.nine
Q: Downloaded the MLS packages Positioning - Eastern/Southern/Western Europe (3 packets) from Jolla Store.
Have I to do some configuration in Pure Maps to make the MLS work? Will the MLS packages be recognized by Pure Maps automatically? I can find no related item in the settings of Pure Maps.
Pure Maps does not access MLS data directly but just gets location information from the GPS device (which may access GPS, MLS offline, no more online location services).
So no configuration on Pure Maps / OSM scout.
But only on settings - location…
Yes, thats my settings now. My system runs in German language so in my above message I did translate the names of the items only flippant + shorten it…
Getting back to the blue marker orientation discussion cause i played a bit outside today with it. First of my compass seems to be working alright.
As it seems -or this is what i understand- the pointy side of the marker seems give the angle you have from north. Ie if you face north the arrow will point to the north, if you turn 90 degrees right the arrow will point 90 degrees right and so on.
No idea which is supposed to be the intended behavior. Its just a bit confusing.
EDIT
Now i got whats going on. The moving pointy side makes sense when you have auto rotation of the map on.
EDIT 2
A suggestion for making it a bit cleared for morons like myself. Three different markers for each state.
Grey round marker that indicates that it doesn’t receive any position info.
Blue round when there is a position but no auto-rotation
Yes, it is correct. It points as you do when you hold the phone. Similar to showing you direction of your move while you navigate, whether it autorotates the whole map or not.
That pointy marker allows you to get out of the metro in unknown place and orient yourself - data that will be lost when you replace it with the round marker.
If you want write it down to explain to the users and submit as PR for docs or any other helpful info that should be on the homepage, please do so.
Re pointy marker without map rotation: It has the same meaning as showing direction, which can be useful without map rotation. Hard for me to explain, as I just start repeating myself. Maybe someone else can help out and explain. For me, it is useful without map rotation.
App doesn’t work. Position is shown at point roundabout 1 km away from my location and doesn’t move. Did a complete reinstall of pure maps and scout server, but no difference. But it seems that’s a system problem cause other apps seem no to get GPS signal too. Any hints what do do without a reflash?
Sounds like you don’t have GPS lock and are mainly triangulated by radio. Don’t think reflash will help, just go outside and wait with a clear sky. Keep an eye on satellite info using GPSInfo
The pointy marker can show the direction in what you are moving. When standing, by the compass. When moving, the compass is not needed and direction of moving is calculated by the present and older positions,
So the pointy position mark can also make sense with turned off compass.
The same way speed display is working. Usually GPS devices make one position fix per second, and so they can calculate the speed by the distances between the measured positions (= m/s).
