Modeling of Wi-Fi IEEE 802.11ac Offloading Performance for 1000x Capacity Expansion of LTE-Advanced

This paper studies indoor Wi-Fi IEEE 802.11ac deployment as a capacity expansion solution of LTE-A (Long Term Evolution-Advanced) network to achieve 1000 times more capacity increase. The objective is to understand how the latest Wi-Fi 802.11ac helps the LTE-A network to accommodate future 1000 times more traffic demand. For the performance evaluation of Wi-Fi, we propose a novel analytical throughput model that captures both key 802.11ac enhancements and multi-cell interference. We provide quantitative evaluation of large-scale indoor Wi-Fi 802.11ac deployment in a real urban scenario by extensive simulations. We conclude that the 1000 times more network capacity can indeed be achieved by indoor Wi-Fi 802.11ac deployment: in particular, when utilizing only the existing IMT license spectrum at LTE-A network, a Wi-Fi density of approximately 1500 access points/km2 (400 Wi-Fi per macro site) is required; With the availability of new 3.5GHz spectrum, 500 Wi-Fi access points/km2 (100 Wi-Fi per macro site) is required. Moreover, we conclude that, compared to the alternative LTE-A femto cell solution, Wi-Fi has the big advantage of saving the new spectrum resource at 3.5 GHz by utilizing its unlicensed spectrum at 5GHz.