Access point selection in beyond 5G hybrid MmWave/Wi-Fi/Li-Fi network

Abstract

5G and beyond networks are key technologies for realizing high data rate applications such as 4K video streaming and virtual reality. To enable these networks, high and ultra-high bands, i.e., millimeter wave (mmWave) and light fidelity (Li-Fi), with theirs wide range of unlicensed spectrum can be auspicious choice but both face serious technical issues that highly degrade their performance. For instance, mmWave and Li-Fi are highly susceptible to blocking probability and co-channel interference, respectively. To address these problems, existing approaches have proposed integration between them under the control of wide coverage Wi-Fi. While this hybrid networks can improve the throughput and experience of user equipment (UEs), access point selection (APS) in downlink scenario can be challenging due to the mixture of bands. In this paper, the conventional signal strength strategy scheme for APS is first explored. Then, an optimization problem is defined to distribute UEs load among network access points (APs), which can maximize the total UEs throughput while maintaining fairness among them. Additionally, a two-steps approach is proposed to efficiently associate UEs to network APs. First, each UE selects its most favorable AP from each network, i.e., mmWave, Wi-Fi and Li-Fi network, independently. Second, each UE is assigned to certain network based on a fuzzy logic (FL) algorithm. In this step, both the instantaneous throughput from each network and data rate of UE are considered. The performance of this scheme outperforms the conventional scheme in terms of throughput per UE, satisfaction of UEs and fairness among them. Moreover, this scheme achieves nearly optimal performance with high reduction in the system complexity.