IssueTracker

Hi,
Fused Location Provider is the recommended way to retrieve device location on Android. It's advertised to fuse data from many sensors (cell towers, Wi-Fi, Bluetooth Low Energy beacons, GPS and motion sensors such as accelerometer) to get the device location in an efficient way. However, the current implementation isn't reliable. I observed the issues in the Google Maps Android app on my Nexus 6P (on Android 7.1, 8.0 and 8.1).

The first time I experienced the issue was more than a year ago when I took my Asus/Google OnHub router usually at my home, to my grandparents home, about 40km away from my home. When I checked Google Maps after having plugged the OnHub to my grandparents modem, it said I was still at my home, while I was 40km away.

The second time was at VIVA Technology in Paris (where Google was a platinium partner), where I was for the 3 days. I tried to get biking directions on the last day to go to the train station, and Google Maps told me it couldn't find a propoer route. Why? It said I was not in France, but elsewhere in Europe! The blue dot (which represents the current location in the Google Maps app) then moved a lot like crazy, like I was in a teleportation pod, but I really was still at Portes de Versailles at the VIVA Technology event. I knew what was the cause of this issue. There was a lot of ephemereal stands, where people brought their Wi-Fi router like I did when I went to my grandparents home, and Google wifi access points location database registered the previous location of all these Wi-Fi routers.

Then it happened during my holidays in Île de la Réunion, where I brought my Asus OnHub, and after 10 hours in an airplane, more than 10Mm (10 million meters, or 10 000 km), Google Maps argued I was still home as long as I stayed within the Wi-Fi range of my router. Then, the location was fixed by itself, and was reporting the right one. Then I moved to another place on the Island, less than 20kms away, I plugged my Asus OnHub on the router of the rent home there, and same issue again! Google Maps reported the older location, 800m higher, kilometers away, with an astonishing "precision" of about 20m. LOL.

Finally, I'm back at my grandparents home, and the issue is happening again, it argues I'm home, but I'm 40kms away.



The big issue is that Google location system assumes Wi-Fi router don't move, while smartphones when Wi-Fi hotspot is enabled, are the first devices that desmontrate the contrary. Light devices like Google Wi-Fi that runs on USB-C are more likely to be carried when going on vacation or on a event, and even without that, people are already moving heavier Wi-Fi routers as seen at tech events or with me and my Asus OnHub. The issues fixes itself within a few days only because there seems to be a periodic wifi location database invalidation, but this is not the right solution.

So how could these issues be automatically prevented?

Cell towers provide location, right? This is the one that can be trusted, since carriers rarely move cell towers as far as I know, and are unlikely to move multiple neighbor cell towers to another location while keeping them neighbor.

Cell towers provide location with low battery consumption with a low accuray, but, IMHO, high reliability. The location reported by cell towers should be used to narrow down the possible location. All sensors/data sources such as Wi-Fi access points, Bluetooth Low Energy beacons, GPS (may come from a repeater that could spoof the satellites? To confirm), reporting a location outside of this area should be invalidated immediately, and not taken into account until their location in the database is fixed. Note that Wi-Fi access points and BLE beacons that are inside the possible area defined by cell towers location should not be ignored if only one or some are invalid.

Also, since Google makes Wi-Fi routers and updates them (OnHub and Google Wi-Fi), a firmware update could add this neat feature: When the router connecivity changes, a check is made first locally to check if it's the same internet IP address as before, and if it's not, it sends it to Google so that it's location is invalidated in the database immediately. The location of the router may also be approximately guessed from the IP address automatically, and be persisted in the location databse.

I think this issue is really important because first, if people notice increasingly unreliable location, they will stop trusting it, which is really bad for Google, all the apps that rely on Fused Location provider, and for UX. And also because location may be used for more critical usages such as emergency calls (I heard Google Play Services added it not so long ago), and for asset tracking in the future with Android Things devices. Showing a wrong location by kilometers, or megameters, while arguing the accuracy is 20meters is a fool statement, not a billions dollars company statement.

I hope for you, and for us, developers, and everything and everyone that is relying on this and us that this issue will be properly adressed.

PS: My dad told me he noticed the accuracy of Google Maps blue dot it worse than before (in comparison of, let's say about a year ago, maybe more, maybe less). Right now, he opened it on his phone while I was writing this issue, and here's what it did, in order:

- Showed a cell-tower precision location
- Showed my home with Wi-Fi "accuracy", which is 40km away, because of this issue.
- Showed a blue dot of a Wi-Fi like "accuracy" of a nearby location (apparently stopped using my OnHub location), but this location is about 100-200m away from our real location, and our current location is not within the blue dot + "accuracy" disc, but far outside of it.