Link calibration in QoS-aware wireless back-haul networks for rural areas

Rural areas all over the world often lacking affordable broadband Internet connectivity. High CAPEX and especially OPEX due to vast and sparsely populated areas often present an uneconomical environment for deploying traditional wireless carrier equipment. Particularly in emerging and developing countries the lack of well-trained personnel requires inherent self-managed networks. To address these issues, we have developed a carrier-grade heterogeneous Back-haul architecture which may be deployed to extend, complement or even replace traditional operator equipment. Our Wireless Back-Haul (WiBACK) network technology extends the Back-haul coverage by building on cost-effective equipment and provides highly automated self-management features still allowing for effective QoS-provisioning. Due to the limited capacity of Wireless Networks compared to cable or fiber networks, it is important to optimally utilize the wireless links and, hence, to configure them properly to match the characteristics of the wireless channel. This link calibration includes selecting the best-suited Modulation and Coding Scheme (MCS), Transmission (TX)-power and other MAC parameters such as the acknowledgment timeout. In this paper, we present our WiBACK architecture and its suitability for deployments in rural regions. Moreover, we propose a link calibration algorithm for IEEE 802.11 links and its crucial architectural role.