A Distributed Scheduling through Queue-length Exchange in CSMA-based Wireless Mesh Networks

抄録

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.