Method and apparatus for enabling the smooth transmission of bursty data in a wireless communications system

Abstract

A method and apparatus for smoothing bit rate transitions in a bursty input data stream. The method includes the steps of receiving the input data stream in a buffer, periodically measuring the occupancy level of the buffer and withdrawing the contents of the buffer at an output rate. In a simple embodiment of the invention, the output rate is increased if the buffer occupancy level is above a threshold occupancy level and decreased if the buffer occupancy level is below a second threshold intensity, where both threshold occupancy levels are dependent on the current output rate. The output rate is made dependent on the buffer occupancy level, which allows the output data stream to have smoother data rate transitions than does the input data stream. As a result, there is little degradation of service quality to other users of the system upon establishing the bursty connection and problems related to convergence of power levels across the entire system are practically eliminated. Furthermore, power amplifier requirements in the transmitter may be relaxed, which can prevent outages of the high-speed link itself. Also, since there are fewer abrupt changes in the output rate, there will be fewer abrupt changes in the induced interference, leading to a higher percentage of call admissions which are retained and hence the capacity is increased.