Transmission power and playout control for packetized audio streaming over wireless links

We investigate joint transmission power control and playout buffer control for packetized audio streaming over wireless links. We propose a novel model formulation to capture the interactions and tradeoffs between transmission power, playout freezing and jitter caused by the buffer underflow and re-buffering. The optimal joint control policy is obtained using a dynamic programming approach to optimally balance the average power consumption against quality of service (QoS). The latter is measured by the duration of playout freezes, frequency and inter-occurrence time of the playout jitters. We also investigate two special cases where only one of the two controls is available. We obtain the optimal policies and explore their structural properties. Based on those, we also design a low-complexity heuristic. Through simulation we see that the proposed scheme improves the QoS by 50% to 80% when compared with standard benchmarks under the fixed power constraints.