MAC Protocol Enhancements and A Distributed Scheduler for QoS Guarantees over the IEEE 802.11 Wireless LANs

In future wireless networks, different traffic classes will exhibit a large variety of characteristics and QoS requirements, such as transmission rate, maximum tolerable bit error rate and timeout specifications. However, currently there is no standard way of guaranteeing QoS in wireless access networks like Wireless LAN based on IEEE 802.11. In this paper, we propose medium access control protocol enhancements and a distributed scheduler for QoS guarantees and fairness over IEEE 802.11 WLAN. The proposed scheme uses distributed scheduling at both the access point and the user terminals to schedule the transmission of packets according to their delay requirements. The algorithms used for both scheduling are the same. A flexible and fair resource allocation method among the traffic classes and the user terminals is provided by this scheme. Its performance has been evaluated using UCB/LBNL/VINT Network Simulator and an implementation in the Linux kernel. Keywords— Wireless LAN, QoS guarantees, fairness, IEEE 802.11 MAC protocol