BARA: a sender based rate adaptation in wireless networks

Wireless communications benefit from multiple data rates under unstable channel conditions. More efficiently modulated user information results in higher overall data rates, but more error-prone information is received. Thus, it is highly important to adaptively choose a proper data rate so as to optimize network performance based on instantaneous channel condition. This procedure is named as rate adaptation. This paper presents a sender-based rate adaptation proposal named Beacon Auto Rate Adaptation, dubbed BARA, to determine proper instantaneous data rate, especially in the case where control frames such as RTS/CTS are not available. Beacon Auto Rate Adaptation is a suite of mechanisms. Firstly, periodic mandatory control frame beacon is used to estimate the initial data rate for sender at the beginning of a transmission. Then data rate is appropriately adapted during the transmission. Moreover, an innovative scheme is proposed to minimize the number of retransmission. Our simulation with IEEE802.11 demonstrates that, although the improvement for single node is not remarkable, the throughput for network can improved more than 100% in high density network.