Network performance analysis on IEEE 802.11g with different protocols and signal to noise ratio values

Wireless local area network (WLAN) based on IEEE 802.11 standards has experienced tremendous growth in recent years. The 802.11g is one of 802.11 standards that offer data transmission at up to 54 Mbps, compared with the 11 Mbps theoretical maximum with the earlier 802.11b standard. This study experimentally examined network performance of an IEEE 802.11g WLAN. It focused on the effect of signal-to-noise ratio (SNR), transport protocol, chipset design, and the impact of file size or the number of users on the network throughput and delay performances. The measurement results indicated that the network delay is exponentially related to SNR. Hence an empirical delay model was developed. The measurements also showed that for a given file size, the network throughput reached a saturation value at a critical SNR. This result confirmed with a throughput model developed for the 802.11b network by Rappaport. Both developed models can be used in conjunction with propagation models and site-specific information to optimally place network access points prior to actual 802.11g wireless network deployment. Throughput measurements were also obtained using transmission control protocol (TCP), multiple network users, and different packet sizes.