Characterizing interference in a campus WiFi network via mobile crowd sensing

Abstract

WiFi networks and smartphones have been penetrating into people’s daily life pervasively. The increasingly dense deployments of WiFi APs have led to the severe spectrum usage overlap and channel interference. In this paper, we proposed a mobile crowd sensing method to characterize the interference experienced by a campus WiFi network by utilizing the powerful sensing capability of smartphone and users’ mobility. We designed and implemented a mobile measurement App. This App can help the volunteers to sense the neighboring WiFi APs in the background on the Android mobile phones. The measurement data are then uploaded to the measurement repository server for further data analysis. Our measurement results showed that both 2.4 GHz and 5GHz WiFi APs have been commonly deployed on campus, and 2.4 GHz APs dominate for around 80% of total measured APs. The spectrum overlap and channel interference in the 2.4GHz band is much severe than that in the 5 GHz band. The rising WiFi interference is due to the uncoordinated planning, random deployment and intensive density of WiFi networks at different locations. Our field measurement study may provide guidelines to design the next generation software-defined WiFi networks in order to achieve high performance with minimized interference.