The Federal Communications Commission (FCC) released the final rule to approve of TV white spaces (TVWS), i.e., locally vacant TV channels, for unlicensed use in 2010. This TV spectrum will mitigate the shortage of wireless spectrum resources and provide opportunities for new applications. TVWS differ from the conventional Wi-Fi spectrum in three aspects: spectrum fragmentation, spatial variation, and temporal variation. These differences make the network design over TVWS challenging and fundamentally different from Wi-Fi networks. While most prior works on TVWS network design focused on outdoor large-area scenario, the important indoor scenario is largely open for investigation.

In this paper, we present WINET (for White-space Indoor NETwork), the first design framework for indoor multi-AP white space network. We optimize AP placement, spectrum allocation, and AP association. Spectrum fragmentation, spatial variation, and temporal variation are all tackled in our network design. We build a test-bed and conduct extensive measurements inside an office building across four months to obtain real-world traces. Experimental results show that WINET can increase AP coverage area by an average of 62.2% and obtain 67.9% higher system throughput while achieving fairness among users as compared to alternative approaches.