QOAR: Adaptive QoS Scheme in Multi-Rate Wireless LANs

With the availability of multiple rates in IEEE 802.11a/b/g wireless LANs, it is desirable to improve the network capacity and temporal fairness by sending multiple consecutive frames over high rate links, as proposed in Opportunistic Auto Rate (OAR). However, the basic OAR does not provide Quality of Service (QoS) guarantee and thus is not sufficient in supporting real time voice/video traffic. In this paper, the authors further enhance the OAR protocol with a set of QoS mechanisms. The proposed QOAR protocol consists of two protocols: a traffic differentiating Flow Weight Adaptation protocol (FWA) that dynamically tunes both contention window and concatenation number per channel access; an Admission Control protocol (AC) that guarantees the bandwidth/delay requirements of multimedia services.