Real-time voice traffic scheduling and its optimization in IEEE 802.11 infrastructure-based wireless mesh networks

This paper studies real-time voice traffic scheduling in IEEE 802.11 infrastructure-based wireless mesh networks. Providing strict latency guarantee for real-time traffic in such network is difficult, and one of the main challenges is the difficulty in coordinating temporal operations of the mesh access points (APs). In this paper scheduling problem for constant-rate voice traffic is formulated as a binary linear programming problem and its optimal solution is given. The computational complexity may prevent the optimum scheduling from implementing in practice. Then a bottleneck-first scheduling scheme is proposed where scheduling decisions at the APs with a higher traffic load are done before those with a lower traffic load. At each AP, voice packets with more hops to their destinations are scheduled first. Numerical results show that the proposed scheduling scheme can achieve the same network capacity as the optimal one while keeping reasonably low transmission delay.