Wireless communication always attracts extensive research interest, as it is a core part of modern communication technology. IEEE 802.11b has become common in recent years largely due to the advantage of User mobility, relatively low acquisition cost, and ease of implementation, thus becoming common for both residential and business places for Internet access. However, the end-user experience has often been less satisfactory than what the technology can offer. IEEE 802.11b WLAN is known to achieve relatively small throughput performance compared to other standards. The focus of this work is on IEEE 802.11b network performance. The quaternary key shifting modulation technique was used for the dissertation while discrete event simulation was the simulation technique used on the Riverbed Modeller software. Results showed that when the data rate was increased from 1Mbps to 11 Mbps which is the optimum value, throughput increased, there was an 80% reduction in delay, and retransmission attempts also decreased to approximately zero, results also showed that when buffer size was increased from 1000bits to 12800bits which is also at optimum value, throughput increased by approximately 90% no data dropped since it will take a longer time for the buffer to be filled up and about zero retransmission attempts was achieved.