I'n not sure that the question is clear or not. What I am interested in is being able to pick up a WiFi signal that is about 800 ft distant. I'd like to be able to do this using a Toshiba Thrive tablet that runs Android OS (JellyBean). The current signal strenght is in the -85-90Dbm, thus it tends to be unstable. There are no physical obstructions other than the walls of building where the router is located. The router is owned by a business and offers a guest access.
I have a couple of Alfa 1000mw USB adapters and another USB adapter that also has the RLT8187 chip set. Of course one impediment is the OS which does not recognize the Alfas or apparently have drivers for the RLT8187 chipset.