Analysis of DoS attacks at MAC Layer in mobile adhoc networks

Wireless network security has received tremendous attention due to the vulnerabilities exposed in the open communication medium. The most common wireless Medium Access Control (MAC) protocol is IEEE 802.11, which assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to disrupt network performance, obtain extra bandwidth and conserve resources. These MAC layer misbehaviours can lead to Denial of Service (DoS) attacks which can disrupt the network operation. There is a lack of comprehensive analysis of MAC layer misbehaviour driven DoS attacks for the IEEE 802.11 protocol in MANETs. This research studied possible MAC layer DoS attack strategies that are driven by the MAC layer malicious/selfish nodes on IEEE 802.11 protocol. Such DoS attacks could caused by malicious and selfish nodes by violating their backoff timers associated with the MAC protocol. Therefore, these attacks are experimentally analysed and evaluated the impact on the network performance and stability in MANETs. The simulation results show that introducing DoS attacks at MAC layer could significantly affect the network throughput and data packet collision rate. This paper concludes that DoS attacks with selfish/malicious intend can obtain at least 50% larger throughput by denying well-behaved nodes to obtain deserved throughput, also DoS attacks with the intend of complete destruction which allow only less than 5% throughput for well-behaved nodes which eventually led to shut-down of the network.