If you are going to be flying for hours in confined area you may wish to suspend aircraft tracking. There's no point sending GPS position reports if they are not required, so there is a cost saving here. A good example of this is agriculture spraying.
The Geofence capability of the Flightcell DZMx allows just that. Operators are able to suspend tracking while the aircraft remains within a specified radius. Moving outside the geofence perimeter will cause geofence mode to be cancelled and tracking to resume automatically.
Triggered events, such as take-offs and landings, can be suspended as well, or sent only when the aircraft is in cellular range. These configuration options are found in the "Tracking" menu in the DZMx display and in the DZMx Connect GUI. The geofence radius (in km) is also set here.
When enabled, the geofence capability is initiated with a long press on the DZMx MENU keypad button.