  With the increasing availability of flexible wireless 802.11 devices, the
potential exists for users to selfishly manipulate their channel access
parameters and gain a performance advantage. Such practices can have a severe
negative impact on compliant stations. To enable access points to counteract
these selfish behaviours and preserve fairness in wireless networks, in this
paper we propose a policing mechanism that drives misbehaving users into
compliant operation without requiring any cooperation from clients. This
approach is demonstrably effective against a broad class of misbehaviours,
soundly-based, i.e. provably hard to circumvent and amenable to practical
implementation on existing commodity hardware.
