Jamming Vulnerabilities of IEEE 802.11e

It has long been recognized that complete jamming of wireless networks can be realized by generating continuous noise with sufficient power in the vicinity of the wireless network. Recent work has shown that for IEEE 802.11b similar jamming effectiveness can be achieved using "intelligent" or protocol specific techniques. These techniques support jamming with low energy requirements and low probability of detection. This paper extends those results to IEEE 802.11e. Many attacks that worked on 802.11b can be applied to 802.11e Some of them are not nearly as effective as they were for 802.11b, while others are more effective. Other jamming techniques specific for IEEE 802.11e are also discussed. We use OPNET to first study the effects of periodic jamming on the network throughput. The critical step for jamming effectiveness is adding intelligence to the jammer by using knowledge of the protocol and exploiting crucial intervals, control messages, and mechanisms. We discover and analyze new vulnerabilities using intelligent jamming in 802.11e. By exploiting the priority levels, we show that "misbehaving" nodes can be used to jam 802.11e by decreasing either the access time or contention window. We also show that the priority level is crucial in this attack. We document the areas of increased vulnerability of this protocol relative to 802.11b. Most importantly, we show that 802.11e can be "jammed" by nodes that obey all protocol rules and use only normal traffic.