Geo-fencing (geofencing) is a programmical method that uses the global positioning system (GPS) or radio frequency identification (RFID) to define or calculate geographical boundaries.
Geo-fencing allows an administrator to set up triggers and handlers so when a device enters (or exits) the boundaries defined by the administrator, an alert is issued or some events can be invoked. Many geo-fencing applications incorporate Google Earth, allowing administrators to define boundaries on top of a satellite view of a specific geographical area. Other applications define boundaries by longitude and latitude or through user-created and Web-based maps.
Geofence virtual barriers can be active or passive. Active geofences require an end user to opt-in to location services and a mobile app to be open. Passive geofences are always on; they rely on Wi-Fi and cellular data instead of GPS or RFID and work in the background.
Geo-Fening Featuring In Taxi-Top Advertising
Since this method can clearly identify the area boundaries, Programmatically you can set variables to determine the particular area id. Then a developer can easily allow particular local advertising banners to display on the tax-top displays. Once the taxi/device enters/leaves the particular area ID, the display can be set to change automatically to those ads allowed to display in relation to that particular area ID.