It's the maps download that goes along with the GPS that requires an internet connection (unless you've pre-downloaded the relevant maps in advance). There are non-map-oriented GPS apps for smartphones, but AFAIK, you have to manually download and install those apps. The GPS apps that typically come on the phones from the manufacturer - Google Maps, etc. - tend to expect an internet connection to be in place. I'd hope these bigger apps will all still give you your coordinates in the absence of maps, there's no reason why they shouldn't, because as jshannon says, the GPS receiver itself is separate from the internet.