Packet transmission scheduling for enhancing total throughput against channel fading in wireless LAN

Abstract

Inefficient channel utilization is still a serious problem in wireless LANs. One of effective solutions is to decrease the frequency of packet loss. While the backoff algorithm in IEEE 802.11 avoids only the packet loss caused by collision, other previous works that prevent the packet loss caused by channel fading improve channel utilization with transmission at a lower rate. However, utilizing lower transmission rate degrades transmission efficiency because the channel is occupied for a longer time. In this paper, we avoid decreasing transmission rate with a novel transmission scheduling. Specifically, transmission to stations under fading channel condition is interrupted until the condition improves, and other transmission is processed on ahead. Moreover, we propose an extended RTS/CTS handshake which quickly detects the improvement of channel condition and minimizes the wasted time even if fading loss occurs. Evaluation results demonstrate that network throughput is improved without degrading the throughput fairness between stations.