Coverage Algorithms for WiFO: A Hybrid FSO-WiFi Femtocell Communication System

We study coverage algorithms for deployment of WiFO - a hybrid femtocell architecture based on WiFi and Free Space Optical (FSO) technologies to significantly increase wireless throughput of existing WiFi networks. In contrast with existing WiFi networks, WiFO incorporates small cell size, line of sight transmissions, and the Gaussian attenuation model of light intensity into the design of the coverage algorithms. Specifically, two types of coverage scenarios - the non- overlapped and the overlapped coverage are presented. For the non-overlapped coverage, we show the bounds of coverage efficiency for a finite rectangle area based on a simple model. For the overlapped coverage, user's SNR profiles are assumed to be given. Using these, three algorithms for determining the optimized deployment based on user's SNR profiles and Gaussian light attenuation models are proposed and evaluated. Simulations results are provided to verify the proposed algorithms.