Abstract: A system and method for ensuring the availability of a radio data communications link for radio data messages between a fleet of mobile stations and a fixed base station is disclosed. The radio data messages between the mobile stations and the base station are composed of both routine messages as well as non-routine, priority messages. A parameter for adjusting the frequency of the routine messages is transmitted from the base station to the mobile stations. Over a selected time period, the number of radio data messages from the mobile stations to the base station which require multiple transmissions for successful receipt by the base station is monitored. At the end of this time period, the parameter is adjusted in response to the number of radio data messages which required multiple transmissions for successful receipt by the base station. The system repeats this method so that the frequency of the routine radio data messages is dynamically controlled.