Categories
Location Maps and Navigation Mobile Phone Network Location

Cellphone location redux

My cellphone for the last three or so years has been a Google Galaxy Nexus which has never shown more that 12 satellites as visible and rarely shows being locked to more than 9. The “time to first fix” can also take several minutes unless it has a pretty good hint on location from some other source. Thus my fixation on network based location services.

Yesterday we received a 2015 model Moto E LTE to replace my spouse’s phone. Out of curiosity I set it to use phone only (GPS with no network assist) and the GPS locked within a second or so and showed 17 satellites visible with 15 locked. I haven’t seen it in the specifications but I suspect it is using the GLONAS system in addition to the GPS system as that is the only explanation I have for the additional satellites and much quicker time to first fix.

So it seems that with a newer phone fussing about outdoor location using cell tower and WiFi AP locations is probably not worth the effort. There should still be room for using those inputs for determining locations when a satellite fix is not possible (e.g. indoors). But the techniques that work there like using RF signatures are quite different than I have been using for outdoor location estimation.