Defending Against Jamming Attacks in Wireless Local Area Networks

Wireless local area networks(WLANs) work upon a shared medium and broadcast data frames via radio waves. These features let legitimate users connect to Internet conveniently at WLAN access points but also let a malicious attacker misuse network flexibly. Attackers can launch jamming attacks by exploiting vulnerabilities in 802.11, which is a dominant protocol used by WLAN. We discuss two jamming attacks, RTS and CTS jamming, and address their attacking conditions and threats. To defend against jamming attacks, a CUSUM based detection method is proposed, which can accurately detect jamming attacks with little computation and storage cost. When continuous attacking packets are sent out, a change-point will appear in a traffic sequence. Our detection method is capable to observe such change-points and then launch alarms. The efficiency of defense methods is verified by simulation results.