Am Fri, 30 Mar 2018 23:27:30 -0600, schrieb rbowman:

Any access point that is broadcasting its SSID. I believe you still
need a connection to allow your device to query the database on
someone's server. Basemaps for an area can be downloaded for local use
but I don't know about the SSID position information.

What you bring up is the exact reason for the question.

Let's state the obvious first:
1. The tablet has no GPS and no cellular data is possible.
2. The tablet is in the car which is driving down the road.
3. That means there is no way to connect to an AP unless it's wide open.

*So how does the WiFi-only table know where it is when driving on a road?*

Certainly the tablet "sees" the many secured and unsecured WIFI AP BSSIDs.
The tablet also knows their signal strength (which approximates nearness).
Of that there is no doubt.

How does the tablet /still/ know where it is even when it has no connection
to any of the access points that it can clearly "see"?

That's the question.