XPost: comp.mobile.android, alt.home.repair   
   From: rragnusen@ultred.com   
      
   Am Sat, 31 Mar 2018 14:05:11 +0200, schrieb Libor 'Poutnik' Støí¾:   
      
   > Android applications and I suppose iOS ones as well   
   > do not determine location on their own,   
   > but ask the OS what the location is.   
      
   Hi Poutnik,   
      
   That's correct, I don't think that's necessarily the only correct answer   
   since an app can maintain its own database of whatever it wants to maintain   
   (e.g., some apps track in a tunnel where they use predictive algorithms).   
      
   In the case of the Google Map app, we all know that Google maintains a huge   
   *online* database of BSSID:location pairs for all access points that have   
   been reported to it by most (not mine) Android phones.   
      
   Everyone on this thread already knows that it's *possible* that Google   
   simply downloads that BSSID:SSID:location:dBM data to the portion of map   
   that is downloaded for offline use with the "OK MAPS" mechanism.   
      
   The main question is how to prove whether that BSSID:location information   
   is actually stored inside the *offline* Google Maps database which is   
   downloaded by the "OK MAPS" mechanism.   
      
   >    Does it track you only within ranges of supposed Wifis ?   
      
   I need to run tests, but the preliminary answer is "yes".   
   It seemed to work best in populated areas moreso than in remote areas.   
      
   If that proves out, that would be a hint that Google Maps is using a   
   previously stored local database of BSSID:location information, which, by   
   the way, may be the main reason that Google offline maps *expire* after a   
   month (actually 29 or 30 days, depending on the platform).   
      
   >    Does it even track you without any wifi in the range ?   
      
   Preliminary results are that "houses" need to be nearby.   
      
   Whether or not that means access points is unknown, but what else can it be   
   using since there is no GPS possible nor is there cellular data possible?   
      
   I think we all suspect that Google maps is downloading to the "OK MAPS"   
   localized database the access point information that most Android phones   
   (not mine) hand it every day, but the question is how to prove that is the   
   case.   
      
   > In case of the former,   
   >   
   >    Does it track you only at known locations,   
   >    where the device has been before ?   
      
   Ah. This is an interesting question, where the tracking was certainly done   
   in an area that I frequent, since it was "in town", as I was leaving the   
   library (where I had been connected prior).   
      
   The Google Map app does ask if it can get location information even when   
   the user is not using the app, so, there "may" be something in your   
   question for us to track down further.   
      
   Thanks for thinking of that, which nobody else had mentioned (AFAIR).   
      
   >    Does it track you even at new locations   
   >    with wifis unknown to the device ?   
      
   That is a good question. I will have to use the tablet in a location where   
   it has never been before to ascertain that answer.   
      
   But, I think we all suspect it simply downloads the BSSID:location   
   information, which is the same information I queried a long time ago to   
   prove we could track someone's cellphone from our desktops at home.   
      
   You have to have a "key" which Google provides for free, and then you give   
   Google *two* SSIDs (the reason for two, as I recall, is a rudimentary   
   security mechanism), and then you give it a bogus signal strength, and if   
   things match up for Google's liking, it hands back the location.   
      
   Of course, Google's own map app is probably not restricted to two SSIDs   
   even as they would want as many as possible for their "triangulation" to   
   work reasonably accurately.   
      
   > It seems to me not probable   
   > to have pre-downloaded all wifi location database.   
   > Perhaps, it may predownload the data for nearby area only.   
      
   That's is the conundrum.   
      
   How does the Google Map app manage to track you when the tablet has no GPS,   
   no cellular, and the WiFi doesn't have the credentials to connect to   
   anything but an access point which is wide open and just happens to be on   
   the road, but you'd pass by that access point fleetingly so there isn't   
   much time to connect to the net.   
      
   Most of us already suspect the "OK MAPS" mechanism downloads this   
   BSSID:location information - but the question is how to prove that is the   
   case.   
      
   > I would rather believe the tablet does not behave   
   > in the way you suppose it to behave.   
      
   That may very well be the case.   
   And I appreciate that sentiment of yours, which is reasonable.   
      
   I think we all know of a good mechanism that might be what it uses; we just   
   need to figure out how to prove that is the case.   
      
   > Sometimes a particular HW is present,   
   > but not available for the user rather for business reasons,   
   > being either deactivated or just not used.   
      
   This might be the case, but I doubt it (but it's always a possibility).   
      
   > It is cheaper to produce 1 version   
   > and selectively disable optional features.   
      
   Yup. Apple does this all the time, e.g., with their modems where they have   
   an iOS device with a fast modem and another with a slow modem, so they   
   permanently slow down the fast modem just so that the user won't see the   
   speed difference in the two devices.   
      
   But this would be permanent, and hence not useful to the app.   
      
   > Or, selectively disable it just for user applications,   
   > but not for the OS.   
      
   This might be the case. I don't see any evidence of this though, in this   
   case.   
      
   > E.g. Xiaomi MI A1 does have the FM radio chip,   
   > ( one can listen the radio via the service menu )   
   > but it is not mentioned in manual   
   > and there is no builtin nor downloadable FM application   
   > that would work.   
      
   This is an interesting example. So it might be the case here, but I doubt   
   it since Occam's Razor tells us that the simplest solution is the most   
   obvious one that we all know already, but which we don't yet know how to   
   prove it's the case.   
      
   Q: How can we prove that the Google App "OK MAPS" mechanism downloads the   
   BSSID:location information of local access points?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)