[QUOTE=Mr Head;21796258]My experience is limited to a first generation Motorola Android and an iPhone 4. Both had to have cell service to perform as GPS. At one critical point we lost the cell connection along with GPS with the Android.
Though the much greater problem was battery life of that phone. It would not charge and guide at the same time. This would eat up the battery in about 2 hours or less. As the phone aged this got worse.
And when I went to my provider for service, I was told....
You guessed it, "They all do that."
And since that old android was not being supported I got to watch as my apps fell out of date. That lead to the iPhone4.
THis works a little better. Voice directions via bluetooth when I use, Google Maps.
Which was one of the driving reasons for the Android.
Battery life is still an issue. Using just the GPS and cell and shutting down all other apps Strava will suck the battery dry in about 6 hours.
That is providing I don't use the phone for anything else.
Interesting, my experience with iPhone was different (moved to a 5 a few months ago). Maybe the differences were due to carrier variances ( I am in VZW) or settings.
I used Navigon ($49?) which requires no cell service as the maps are downloaded to your phone on an iPhone 4 several times in places with no cell service and I have navigon/GPS-current running all day with my phone plugged in and stayed 100% charge all day. I get the same xperience on my iPhone 5 with Verizon now living a 1,000 miles away.
Who knows...all of the experiences with smartphones could be highly variable bassed on the apps on our phones, our carriers's own version, our own personally selected settings. Hard stuff to figure out on a forum.