Volume 25 (2017) Pages 174-181
Wireless Mesh Networks (WMNs) over CSMA MAC (especially IEEE 802.11) are an attractive solution to widen the coverage area of the Internet in unlicensed frequency bands. Although such CSMA-based WMNs have been deeply investigated for a long time, they still suffer from heavy interference due to hidden terminals. In this paper, we accelerate the performance of CSMA-based WMNs by introducing a distributed scheduling scheme that exchanges the transmission-queue length information in real-time among neighbor nodes. In our scheduling scheme, we exchange the information of transmission queue-lengths among neighbor nodes in real-time, and allow transmitting frames to the node that has the longest queue length among its 2-hop distance. The proposed scheduling scheme can be regarded as a distributed design of so called ‘Max-weight’ scheduling.By combining CSMA with the queue-length based scheduling, we significantly reduce collisions due to hidden terminals and improve the performance with a small overhead of queue-length fields in MAC frames.