Queue management algorithm for multirate wireless local area networks

Wireless local area network (LAN) has become popular due to the capability of supporting high data rates in ubiquitous computing. These high data rates are possible through new modulation schemes that are optimized for channel conditions. Especially, IEEE 802.11b supports the various data rates, 11 Mbps, 5.5 Mbps, 2 Mbps and 1 Mbps according to the channel conditions between the access point (AP) and the mobile station. The coverage area supported by the high data rate such as 11 Mbps is very small. However, the lower data rate increases the coverage area, thus the change of data rate can overcome this coverage problem of the high data rate. There are many wireless packet scheduling and buffer management algorithms, but they assume a wireless channel supporting only single base-rate and hardly take advantage of high data rate when multiple data rates are possible. In this paper, we propose the new queue management algorithm in order to utilize high data rate efficiently in the current wireless LAN. Basically, the proposed queue management algorithm manages the priority queue of packets, where packet with shorter transmission time has higher priority, since the transmission time is highly dependent on the available data-rate to the mobile station. We show our suggested algorithm achieves high throughput through the simulation in based in wireless LAN environments based on the IEEE 802.11b.