Analogue RoF-enabled HetNet architecture for hybrid Li-Fi/Wi-Fi indoor access

To meet the ever-increasing internet-of-things (IoT) demands, the majority of indoor activities are currently accommodated by the existing Wi-Fi networks, despite the extremely limited licensed spectrum and significant challenges in resource allocation and capacity. This paper introduces an optical-aided indoor heterogeneous network (HetNet) that combines Li-Fi and Wi-Fi using an analogue radio over fiber assisted passive optical network (A-RoF assisted PON) architecture, with simplified optical network units (ONUs). Explicitly, by centralizing and optically processing the hybrid Li-Fi and Wi-Fi services in the proposed optical line terminal (OLT), the A-RoF aided PON is capable of reducing the digital signal processing (DSP) complexity of its ONUs. Moreover, we propose an A-RoF-aided multiple-input-multiple-output (MIMO) scheme to further simplify the PON ONU architecture. Then, based on the proposed optical-aided centralized HetNet, a flexible SNR-based adaptation method is conceived for enhancing the system throughput and quality of service (QoS). We experimentally demonstrate the feasibility of the optical-aided HetNet and verify the proposed Li-Fi/Wi-Fi adaptation algorithm. As given by our proof-of-concept experiment, results show that the proposed optical-aided Li-Fi/Wi-Fi HetNet can simultaneously support high-quality Li-Fi and Wi-Fi transmission with centralized optical control and dynamic resource allocation.