TVWS assisted performance anomaly mitigation exploiting spectrum heterogeneity

Abstract

Super Wi-Fi is a Wi-Fi-like service utilizing TV white spaces (TVWS), which has been revealed to provide higher data rates in the outskirts of Wi-Fi’s coverage, thanks to the spectrum heterogeneity between Wi-Fi bands and TVWS. Motivated by this, this paper proposes co-locating a Super Wi-Fi access point (AP) with a Wi-Fi AP aiming to mitigate the performance anomaly of the WLAN by relocating low-rate Wi-Fi stations (STAs) to Super Wi-Fi in the outskirts of Wi-Fi’s coverage. Then, the proposed strategy can enhance average per-STA throughput of both Wi-Fi STAs and relocated Super Wi-Fi STAs while also improving the data rate of Super Wi-Fi STAs, than they would achieve with the legacy Wi-Fi. To quantify such performance improvement, we model the system as a series of two-dimensional Markov chains and provide an in-depth analysis of steady-state probabilities and per-STA throughput. Numerical analysis has shown that Super Wi-Fi co-location improves not only average per-STA throughput but also spectral efficiency, compared to the legacy Wi-Fi with 20 or 20+20 MHz bandwidth for the single BSS scenario. In addition, average per-STA throughput and spectral efficiency are also enhanced in the OBSS scenario both in rural and urban environments. Hence, the co-location strategy is proven to be quite effective in enhancing WLAN’s performance.