A High TCP Performance Rate Adaptation Algorithm for IEEE 802.11 Networks

Abstract

Rate adaptation is a link layer mechanism critical to the system performance by exploiting the multiple transmission rates provided by current IEEE 802.11 WLANs. The key challenge for designing such an algorithm is how to select the most appropriate transmission rate under different environments. The first generation rate adaptation schemes perform poorly in a collision dominant environment because they do not differentiate frame losses caused by collision from channel degradation. The second generation schemes use RTS/CTS control frames to differentiate frame losses. However, introducing the overhead may lower network performance especially when the data frame size is small. This paper gives several guidelines on how to design an efficient rate adaptation scheme and proposes an algorithm called Advanced Rate Adaptation Algorithm (ARA). ARA is implemented along with four other representative rate adaptation schemes on a Linux-based testbed. Experiment results show that ARA outperforms other rate adaptation schemes in most scenarios.