Perfomance Analysis of 802.11b Networks

Abstract

Wireless local area networks (WLANs), especially those incorporating the 802.11b standard, have experienced rapid evolution and unprecedented widespread deployment during the past few years. Increasing research led to the advent of new technologies and standards in WLANs enabling them to achieve higher data rates (e.g., from 2 Mbps to 11Mbps) and wider coverage. Since 802.11b networks operate in the unlicensed ISM (Industrial, Scien- ti¯c and Medical) band of the frequency spectrum, they experience interference from other devices operating in the same band. Therefore, it is important to understand the performance of 802.11b networks, in terms of throughput and quality (packet error rate), for both TCP and UDP data transmissions over these networks, under interference. This thesis presents a detailed experimental study of the impact of self interference (other 802.11b access points and terminals), Bluetooth interference and microwave interference from household appliances on 802.11b networks. A mathematical model for predicting the throughput of 802.11b networks in the presence of self interference is developed. Such a model is extremely useful in planning WLAN network deployments in indoor environments and in proactive performance management.