Originally Posted by
noglider
In case you haven't surmised from the answer, yes, the GPS receiver is independent of wifi, though when you have both, they can work together.
When you are outside, WiFi is useless for location (the range of WiFi is too short). Cellphones can use cell towers for rough location too. GPS is much more accurate but it takes awhile to lock (once it's locked, GPS is fast). WiFi and cell towers are fast but inaccurate. They can make the GPS lock in faster and the work indoors where GPS tends not to.
Originally Posted by
noglider
If you're not interested in seeing your progress on a map while you are riding, the tablet can probably do what you want.
If you have a GPS receiver in your tablet or smartphone, you can see your progress on a map while you are riding. (Assuming you can mount the thing.)