A distributed scheduling mechanism to improve quality of service in IEEE 802.11 ad hoc networks

We introduce a queue-adaptive scheduling mechanism that facilitates scheduling differentiation among nodes having traffic within the same access category in IEEE 802.11-based ad hoc networks, which to the best of our knowledge, has not been previously addressed. We investigate the effectiveness of the proposed mechanism, which is easy to implement and requires minimal overhead, via simulation. More specifically, we investigate the effectiveness of dynamically controlling the values of the interframe space, contention window, and the transmission opportunity in the context of voice over IP in a distributed IEEE 802.11 ad hoc network. Our simulation results show that the proposed mechanism considerably lowers the percentage of dropped packets as the number of active calls increases beyond the network´s call carrying capacity, dramatically improves system stability at higher traffic loads, and results in a significant improvement in call carrying capacity.