Protecting IEEE 802.11 Wireless LANs against the FCS False Blocking Attack

Abstract

Advances in mobile communication technologies have been promoting the Internet access through wireless networks. According to the data collected by International Data Centre (IDC), there have been more than 45,670 hotspots deployed worldwide. The hotspots provide high-speed Internet access service to users with mobile devices such as laptops or PDAs through the IEEE 802.11 wireless local area network (WLAN) technologies. Because WLAN technologies use air as their transmission medium, the security of data transmission over the exposed medium can be easily impacted by environmental factors such as background noises, eavesdropping, and attacks. Some security weaknesses in the IEEE 802.11 protocol have been identified and effectively resolved in previous research works. In this paper, we introduce a new pattern of 802.11 false blocking attacks - the FCS false blocking attack, in which the attacker continuously transmits data with erroneous FCS values. To cope with the performance degradation caused by such an attack, the corresponding detection and recovery mechanism is also proposed. Simulation results show that with the proposed detection and recovery mechanism, a station can positively detect the ongoing attacks of FCS false blocking and effectively escape from the FCS false blocking attacks and use the WLAN bandwidth effectively.