Enhancing Wireless Medium Access Control Layer Misbehavior Detection System in IEEE 802.11 Network

Wireless Medium Access Control (MAC) protocols such as IEEE 802.11 use distributed contention resolution mechanisms for sharing the wireless channel. In this environment, selfish hosts that fail to adhere to the MAC protocol may obtain an unfair throughput share. For example, IEEE 802.11 requires hosts competing for access to the channel to wait for a "back-off" interval, randomly selected from a specified range, before initiating a transmission. Selfish hosts may wait for smaller back-off intervals than well-behaved hosts; thereby obtaining an unfair advantage. We show in this thesis that a greedy user can substantially increase his share of bandwidth, at the expense of the other users, by slightly modifying the driver of his network adapter. This study is a complementary of DOMINO System model to enhance the detection system in the MAC layer of IEEE 802.11; our enhanced system is a piece of software to be installed in or near the Access Point. The system can detect and identify greedy stations without requiring any modification of the standard protocol. We illustrate these concepts by simulation results.