An Ultra-Wide Overlay Cognitive Radio System for Wireless Backhauling for Small Cells.

During the last years WLAN (IEEE 802.11) has become the primary wireless access technology. However, the fast evolution of peak data rates and the wide deployment of WLAN hotspots results in the backhaul connecting such small cells becoming a bottleneck. To provide a high capacity backhauling, we propose COUWBAT, a COgnitive Ultra-Wide BAckhaul Transmission system, featuring extremely flexible usage of a very wide range of non-contiguous, dynamically allocatable spectrum for backhauling in rural areas where a wired solution is not economically feasible. The proposed cognitive MAC layer supported by protocol in-band signaling, ensures the continuity of connectivity with high capacity even in case of fast changes in spectrum availability. The proposed system was prototypically implemented and evaluated exhaustively analytically and also by means of network simulations using ns3. The source code of our simulation model is provided to the community as open source.