Wireless networks have been rapidly integrated with the wired Internet
and have been widely deployed. In particular, IEEE 802.11b WLAN is the
most widespread wireless network today. The IEEE 802.11b WLAN supports
multiple transmission rates and the rate is chosen in an adaptive manner by an
auto rate control algorithm. This auto rate control algorithm deeply affects the total
system performance of the IEEE 802.11b WLAN. In this paper, we examine
the WLAN performance with regard to the auto rate control algorithm, especially
the ARF scheme, which is the most popular auto rate control algorithm in
802.11b based WLAN products. The experimental results indicate that the ARF
scheme works well in the face of signal noise due to node location. However, the
ARF scheme severely degrades system performance when multiple nodes contend
to obtain the wireless channel and the packet is lost due to signal collision.