Fallback Offline cell data based geolocation
Submitted by Elad Alfassa
Mozilla released their cell database in public domain, https://location.services.mozilla.com/downloads
The files are small enough to include with all GeoClue installations, so in theory you could use them as fallback for when you do have a cellular modem but don't have network (ie. if you exceeded your data quota).
It should only be used as fallback because if you do have network it would still be better to query Mozilla's servers, as they'd be more up-to-date and thus more accurate.