PHY layer access misbehavior in WLAN networks: A game theoretical approach
Probir Khaskel · 2005
This thesis investigates the possible exploitation of the standard channel access mechanism of IEEE 802.11a Wireless Local Area Network (WLAN). We argue that by modifying the Clear Channel Assessment (CCA) sensitivity level, a group of user can achieve higher throughput than other users in a system. The assumption is that all users have the perfect knowledge of the network condition. We model this competing scenario with the help of appropriate tools of Game Theory, to analyze users’ short term as well as long term gain and its impact on the system, focusing on efficient usage of the radio resource. At the same time, system stability and counter measures to dissuade the greedy users in operator’s point of view, is part of our study. Results have shown that in a single cell system, a group of user can achieve higher throughput than the rest of the users by adaptive modification of their CCA level, however, the overall system performance deteriorates. Therefore, a single cell system demands greater monitoring to dissuade any defection from the standard protocol. Multicell system throughput can be increased by around two times compare to the ideal system (following the standard protocol) by adaptive modification of the CCA level based on the network condition. The group formed by a smaller number of users achieve even better througput by adaptive modification, however, the overall system performance degrades. Users are more likely to cooperate in a multicell system.