A Game-Theoretic Study of CSMA/CA Under a Backoff Attack

Abstract

Abstract-CSMA/CA, the contention mechanism of the IEEE 802.11 DCF medium access protocol, has recently been found vulnerable to selfish backoff attacks consisting in nonstandard configuration of the constituent backoff scheme. Such attacks can greatly increase a selfish station's bandwidth share at the expense of honest stations applying a standard configuration. The paper investigates the distribution of bandwidth among anonymous network stations, some of which are selfish. A station's obtained bandwidth share is regarded as a payoff in a noncooperative CSMA/CA game. Regardless of the IEEE 802.11 parameter setting, the payoff function is found similar to a multiplayer Prisoners' Dilemma; moreover, the number (though not the identities) of selfish stations can be inferred by observation of successful transmission attempts. Further, a repeated CSMA/CA game is defined, where a station can toggle between standard and nonstandard backoff configurations with a view of maximizing a long-term utility. It is argued that a desirable station strategy should yield a fair, Pareto efficient, and subgame perfect Nash equilibrium. One such strategy, called CRISP, is described and evaluated.Index Terms-Ad hoc LAN, game theory, MAC protocol, selfish behavior.

Applications of Repeated Games in Wireless Networks: A Survey

“…While the solution proposed in [23] requires the modification in the MAC layer of wireless nodes, the proposed approach in [25] can protect wireless users from selfish users without any change to the MAC protocol. With the same players, their actions are the selections of backoff configurations.…”

Fair Bandwidth Sharing in Network Using FCFS-TP Protocol

“…Much researcher has been performed on "fair queuing" algorithms for achieving a fair allocation of bandwidth on a shared link [3], [4]. Consider the system shown in figure 1, where a node maintains several queues which store packets to be transmitted on an output link.…”

“…The GPS discipline cannot be accurately implemented in practice, since data transmitted in real network is packetized. There are several packet fair queuing algorithm which approximate GPS under the constraint that each packet must be transmitted as a whole [3], [4], [1], [5], [6].these protocol are centralized by nature, as noted above. There has been some work on achieving fairness using distributed MAC protocol for wireless network [7], [8].…”

“…Reference [4] Provides security against back off attack but it does not provide bandwidth with respect to the relative weight. There has been work on distributed protocols that take priority, when performing medium access control [9], [10].…”

Impact of Contention Window Cheating on Single-Hop IEEE 802.11e MANETs

“…However, it cannot be used in ad-hoc networks. Theoretical research pertaining to backoff attacks in ad-hoc networks has been published by Konorski (e.g., in [6]). A game theoretic approach is used to provide incentives for proper cooperation.…”