A communication system comprises a radio to transmit and receive communication signals to and from a selected ground station; and a management unit coupled to the radio and operable to dynamically set a threshold value for selecting another ground station based on a signal strength corresponding to the selected ground station. The management unit is operable to select another ground station when a signal strength corresponding to the other ground station exceeds the signal strength corresponding to the selected ground station by more than the threshold value set by the management unit.