foursquare location over wifi

Question

We are planning to use screens with realtime user check-ins on some events. To to make it easier for users to check-in (mobile internet such as GPRS or 3g has a pure connection) we want to add mobile wifi hotspots around it.. but I fear there could be some trouble with detecting location, because foursquare can remember GPS coordinates from wifi hotspot and use them override GPS or mobile networks (if location data are present).

How could we fix this issue, to get opportunity move hotspot over the city, but locate users correctly each time - always change MAC or SSID, some other way?

Answer 1

Unfortunately, most of the "remembering GPS coordinates from wifi hotspots" is done by the OS, not by Foursquare. I believe the current versions of iOS, Android, and BB all do this automatically to some extent and Foursquare is just getting the GPS coordinates the OS provides it with.

However, I do know that the OSes use a combination of the SSID and the MAC address of the router to determine what router they're looking at. If you change both the SSID and Mac address of the router, then, there will be no way for the OS to "misremember" it. Even if you don't make those changes, then I've usually found the OS to realize its mistake pretty quickly if it has line of sight to the sky and can get a good aGPS fix from a satellite.