A system and method for monitoring and adjusting the data transmission rate of a forward link RF signal from a base station to a mobile platform to maintain a desired, minimum link margin with each of the mobile platforms. The system involves using a signal quality monitoring subsystem carried by each mobile platform during the normal course of its operation to transmit signal quality information via a return link to the base station. The base station uses the signal quality information to monitor and adjust the signal quality of subsequent forward link signals transmitted to the mobile platforms in a manner that optimizes the data transmission rate of the forward link signals. The present invention better accounts for time varying factors that influence the signal quality of received forward link signals by the mobile platforms and obviates the need for mobile test platforms or other expensive and relatively complex methods for predicting needed data transmission rates for the forward link signals.