WiFi Dimensioning to offload LTE in 5G Networks

On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Long Term Evolution (LTE) and Wireless Fidelity (WiFi) cooperation is needed in order to ensure a balanced traffic load based on different criteria so that the end user will benefit from the maximum throughput with no disturbance or deterioration in the service quality. Thus, alternative plans for exploiting already existing under-utilized WiFi infrastructure become more attractive than expanding the LTE spectrum or increasing the capacity by deployment of additional LTE Base Stations (BSs). To find a more effective spectrum utilization method, alleviate the spectrum scarcity problem of cellular networks and ensure additional capacity, we propose in this paper a solution to calculate the minimum needed number of WiFi Access Points (APs) that will be able to handle the transferred heavy users from LTE advanced (LTE-A) to WiFi. The dimensioning method that we propose in this paper is based on the remaining available capacity of WiFi channels taking into consideration the overlapping characteristics of the physical channels to estimate the percentage of busy time or occupation of the AP channels. Based on this approach, we can investigate first the remaining available capacity in terms of available throughput of WiFi that could be distributed over the transferred LTE users, then the minimum required number of WiFi APs that will be supporting the LTE network for efficient traffic offloading.