Comparing Downlink Capacity between Super Wi-Fi and Wi-Fi in Multi-Floored Indoor Environments

Abstract

Super Wi-Fi is a Wi-Fi-like service exploiting TV white spaces (WS) via the cognitive radio technology which is expected to achieve larger coverage than today’s Wi-Fi thanks to its superior propagation characteristics. Super Wi-Fi is currently being materialized as an international standard, IEEE 802.11af, targetting indoor and outdoor applications. This thesis demonstrates the potential of Super Wi-Fi in indoor environments by measuring its signal propagation characteristics and comparing them with those of Wi-Fi in the same indoor structure. Specifically, this thesis measures the wall and floor attenuation factors and path-loss distribution in 770 MHz and 2.4 GHz, and estimates the downlink capacity of Super Wi-Fi and Wi-Fi according to wide-accepted indoor path loss models. The experimental results reveal that TVWS signals can penetrate up to two floors and provide favorable coverage up to one floor above and below. In addition, TVWS can not only extend the coverage of Wi-Fi but also significantly mitigate shaded regions of Wi-Fi while achieving almost homogeneous data rates in the Wi-Fi’s coverage. The observed phenomena imply that Super Wi-Fi may be suitable for indoor applications with requirements of low-to-moderate data rates, extended horizontal and vertical coverage, and fair rate distribution within the service coverage.