Characterizing the end-to-end throughput in WMN using multiple directional antennas

A potential application of Wireless mesh networks (WMN) technology is using WMN as backbone for wireless access networks. In WMN backbone, the throughput is mainly limited by 2 factors: the ingress/egress congestion in gateway and link interference caused by simultaneous transmissions. Recent study found deploying multiple gateways in WMN is an efficient way to alleviate the ingress/egress bottleneck. Besides, utilizing multiple channels, multiple radio interfaces and directional antenna technology in WMN can greatly alleviate interference problem. In the paper, we propose a practical wireless mesh networks architecture using multi-channels, multi-radios and multiple directional antennas. The end-to-end throughput characters of the proposed WMN are studied based on a network model considering the directional antenna. A STDMA based centralized link scheduling algorithm is used to ensure proper operation of the backbone transmission. We provide necessary conditions to verify the feasibility of rate vectors in the networks, and use them to derive upper bounds of achievable end-to-end throughput. The approaches are illustrated by simulation examples. The results show our scheduling algorithm have better throughput performance compared with scheduling algorithm using greedy method. The simulation also shows that the scheduling procedure and compute time of our algorithm is practical in the WMN backbone networks.