Exploiting IEEE802.11n MIMO technology for cost-effective broadband back-hauling

The lack of affordable broadband Internet connectivity in rural areas, especially in emerging regions, is seen as a major barrier for access to knowledge, education or government services. In order to reduce the costs of back-hauling in rural regions, often without access to a stable power grid, alternative solutions are required to provide high-bandwidth back-hauling at minimal power consumption to allow solar-powered operation. In this paper, we show that cost-effective low-power IEEE802.11n (MIMO) hardware together with a single cross-polarized antenna can be a viable solution to the problem. Our study shows that up to 200 Mbps of actual throughput can be achieved over distances larger than 10 km while the power consumption of a typical forwarding node is well below 10 Watts (http://wiback.org/repeater) - suitable for a cost-effective solar-powered operation. Through theoretical analysis and extensive measurements we show that such a low-cost setup can be used to establish reliable long-distance links providing high-bandwidth connectivity at low latencies and consequently providing the capacity demanded by today's services - everywhere. Exploiting these findings we are in the process of extending existing fiber-based infrastructures in rural Africa with our Wireless Back-Haul (WiBACK) architecture.