Tools and Techniques for Measurement of IEEE 802.11 Wireless Networks

With the growing popularity of wireless local area networks (WLANs) has come an increased need for effective measurements of real-world WLANs and their applications. This paper presents tools and techniques for measuring IEEE 802.11 WLANs. The techniques include details on setting up a PC as a wireless access point and building a wireless sniffer while the tools include programs for measuring link, network and application layer traffic. The tools are all open-source software available for download and the techniques all use open-source software and off-the-shelf hardware components. Together, these tools and techniques facilitate WLAN performance analysis across network layers in a flexible, accurate and cost-effective manner. To illustrate the usefulness of these tools and techniques for gathering WLAN measurements three case studies are presented: a streaming video session showing cross-layer performance; network characteristics of a wireless hand-held game; and measurements of access point queue size. Research employing these tools can yield more accurate WLAN models and more realistic evaluation of proposed WLAN changes in a network testbed.