In one disclosed embodiment, communication between a mobile unit and a base station is performed at a data transfer rate selected from, for example, a finite set of HDR data transfer rates. Meanwhile, the mobile unit continually computes a moving average of the data transfer rates. The mobile unit also ascertains a supportable data rate for receiving data. The supportable data rate can be selected from a finite set of HDR data transfer rates. In order to maintain the moving average of the data transfer rate within a specified range, the mobile unit transmits maximum data rate requests or null data requests to the base station. The maximum data rates requested by the mobile unit are equal to or lower than the supportable data rate.