Chaz Does not have a GPS chip.
Assisted GPS uses the known precise location of cell towers to augment the accuracy from the satellites, and can give a rough location of your device if there is no satellite visible (from inside a house, for example). Some tablets will save the last location that is given by your WiFi modem too (I suspect that is the case of your tablet).
The tower uses GPS to find its location, and compare with its accurately know location. This error is sent to your tablet over cell signals and corrects for the small error from the GPS signal at your tablet. Unassisted GPS is probably good to 10 to 20 meters while assisted GPS can be good to 2 meters.
I don't know if ASIAIR requires a true GPS signal when it issues a system call to obtain Latitude and Longitude. If it does, that can explain your problem.
However,since you do not even have a GPS, I suspect that your tablet also does not have a cell modem to get assisted GPS when there is no WiFi signal. With iPads, for example, you need the "WiFi+Cellular"option to have a built in GPS; otherwise the WiFi-only iPad models need WiFi connection to get a rough location.
All Smart phones, on the other hand, appear to have some form of GPS even without a WiFi signal (since they have cell modems).
However, you should be able to use the entry screen of the ASIAIR to enter your Latitude and Longitude that I mentioned in a previous posting. Did that not work for you? If not, send ZWO support an email.
Chen