quote:Originally posted by johngenx
SPOT uses Gobalstar, but seems to be way more reliable than the GlabalStar sat phones. Not sure why. Irridium is much better, but still not completely reliable. We've used an Irridium phone quite a few times, and it's been very good, but clear sky view is pretty important. Even a tent causes a loss in reception quality.
Globalstar satellites are in orbits sort of aligned with the equator. I don't think they even work near the poles. So if you're going far toward the poles, use Irridium. Irridium's satellites are in polar orbits, so their coverage actually is more dense as you go far north or south.
SPOT's advantage over Globalstar phone calls is that SPOT automatically retries making contact, and is only one-direction, while phone calls have to be redialed and are full duplex.