In this paper, a fair Medium Access Control (MAC) scheme is proposed to defend against Request To Send (RTS) attacks in IEEE 802.11 networks. The existing solutions have demonstrated their effectiveness in authentication or traffic detection. However, they are difficult to deploy in wide area and public network scenarios. The proposed light-weight MAC scheme tries to prevent RTS attackers from occupying network channel resources maliciously through a virtual queue management. Simulation results show that the proposed MAC scheme can defend against RTS attacks effectively.