WiserAnalyzer: A Passive Monitoring Framework for WLANs

Due to low hardware costs, availability of unlicensed spectrums and support of mobility, WLANs have been widely adopted in home, enterprise, hospital, and campus environments. These networks are used for various purposes including VOIP, data services and inventory management. The QoS in WLANs may be degraded due to a number of reasons such as environment changes, hidden terminals, and asymmetric relationships between wireless nodes and/or malicious usage. These problems are exacerbated by the fact that some chipset vendors do not fully comply with the IEEE 802.11 specifications, and give unfair access opportunities to their wireless devices. This paper introduces WiserAnalyzer, a passive monitoring tool to analyze WLANs for inference of nodal relationships, detection of malicious usage or incompliance to the IEEE 802.11 specification. We also present analysis of user activities based on traces collected from the University of Houston campus WLAN.