Energy-Aware Rate Adaptation Algorithm for High Throughput IEEE 802.11n WLANs

Abstract

IEEE 802.11 has been developed rapidly especially to produce High Throughput (HT) and Very High Throughput (VHT) in Wireless Local Area Network (WLAN). As a consequence, a new rate adaptation algorithm is required that can control the bandwidth of the channel, guard interval, number of spatial streams, and modulation and coding rate scheme (MCS) most appropriate for data transmission. Several algorithms have been proposed in the literature, but they do not consider energy efficiency. In this paper, we propose an energy-aware rate adaptation and call it as Adaptive Power Automatic Rate Fallback for High Throughput (APARF-HT) algorithm. We classify the data rate in IEEE 802.11n WLAN into group rate. If the resulting data transmission reaches the threshold then the transmitted power is decremented while still keeping the data successfully transmitted. If the transmit power has reached the minimum, then the data rate is incremented in the group rate, but if the rate is maximal in the group rate then the group rate is also incremented. So in APARF-HT, transmit power, bandwidth, guard interval, number of data streams and MCS are used dynamically during data transmission to generate optimal throughput and energy consumption. The proposed algorithm is implemented and tested using NS-3. The simulation results show that APARF-HT produces lower energy consumption per bit compared to a similar algorithm.