At least with an iPad, it comes in two favors:
-Cellular, that includes the GPS chipset (I'm told its all one)
-WiFi only, no GPS
WiFi only models simply won't work with GPS because there is none installed. And they can't reference the cell sites for location because they don't have that capability either.
Full GPS/ Cellular chipset iPads, while they have the capability, don't need to look at cell towers because you're outside traveling anyway. The whole triangulation thing is used for 911 1st responders and locating bad guys inside of houses, etc.