An energy-aware retransmission model for multimedia communications over wireless networks. (c2010)

Abstract

Traditional error recovery schemes such as automatic repeat request (ARQ) and incremental forward error correction (FEC) rely on immediate retransmissions to deal with transmission errors. Such an approach leads to substantial energy drain and notable performance degradation in case of multimedia communications over wireless networks especially when the probability of data error is high. Moreover, retransmissions negatively impact the performance of other mobile nodes due to the nature of resource sharing in wireless environments. In this thesis, an energy-aware retransmission scheme for multimedia distribution over wireless networks is designed, implemented, and evaluated in different realistic network scenarios. The proposed scheme adapts the retransmission rate based on the predicted channel conditions in a way that keeps the quality of service metrics within the desired range. Performance results using ns2 simulations demonstrate reduction of up to 50% in terms of energy consumption while maintaining the target quality constraints. Results also show that the proposed scheme outperforms the default WLAN medium access control (MAC) protocol in terms of packet delay that is an important metric for real-time multimedia applications.