Service area for navigational smartphones
With all this enthusiasm about smartphone turn-by-turn navigation making dedicated PND obsolete, I haven't seen any discussion about how well navigational apps work when a smartphone enters an area of no-service. Are there GPS chips onboard smartphones? Or do they all work by using cell tower geolocation? My concern is to be somewhere I couldn't receive directional guidance, nor be able to call for help at the same time. At least with my dedicated GPS, I'm still getting satellite data wherever I am. So with a smartphone, do I have to drive around until I get a signal? That's comforting when you are lost, isn't it?