Rethinking Mobile Data Offloading to Combine Wi-Fi and Small Cell in Unlicensed Spectrum

Abstract

Traditional mobile data offloading transfers cellular users to Wi-Fi networks to relieve the cellular system from the pressure of the ever-increasing data traffic load. The spectrum utilization of the Wi-Fi network is bound to suffer from potential packet collisions due to its contention-based access protocol, especially when the number of competing Wi-Fi users grows large. To tackle this problem, proposing to transfer some Wi-Fi users to be served by the LTE system, in contrast to the traditional mobile data offloading which effectively offloads LTE traffic to the Wi-Fi network. We investigate three different user transfer schemes according to the availability of channel state information (CSI): The random transfer, the distance-based transfer, and the CSI-based transfer. In each scheme, the minimum required amount of unlicensedresources under a given transferred user number is analyzed. Furthermore, we utilize the Nash bargaining solution(NBS) to develop joint user transfer and unlicensed resource allocation strategy to fulfill the win-win situation for both networks, whose performance is demonstrated by numerical simulation.