Fine-tuning the Femtocell performance in unlicensed bands: Case of WiFi Co-existence

Femtocell and WiFi play crucial roles in sustaining the continued growth in mobile traffic. Deploying Femtocells in WiFi hotspots would allow the access providers to provide more capacity for users and improve their quality of experience during mobility. Hence, the co-existence of Femtocell and WiFi carries critical importance for improving the total performance of the users and meeting the promised quality of service (QoS) satisfaction of Femtocell end users. In this paper, we propose and develop a framework allowing to make use of unlicensed band and to increase the total throughput of Femtocells while offloading the traffic of Femtocell users to unlicensed bands in case of severe interference with Macrocell. The channel access of both Femtocell and WiFi networks are analytically modeled and numerically verified. Moreover, the effects of WiFi channel access parameters on the performance of WiFi and Femtocell networks are investigated. Numerical evaluation of our proposed scheme show that by adequately tuning and giving priority, the throughput of small cells and utilization of unlicensed spectrum have been improved.