An optical backhaul solution for LiFi-based access networks

The light fidelity (Li-Fi) technology is being considered as one of the most promising solutions that can achieve a dramatic increase in communication capacity and a significant reduction in transmission latency especially when it is deployed in the indoor scenario. This technique can enable fully networking capabilities by exploiting the high speed transmission of visible light communication (VLC) technique and supporting massive deployment of LiFi access points to create a network of attocells. In this paper, we investigate the design of an optical backhaul network architecture that can provide efficient interconnection for LiFi access points. Specifically, we propose a LiFi access-point structure implementing orthogonal frequency division multiplexing (OFDM) and optical encoding technique to provide multi-users access and allow all-optical processing and transmission in the backhaul network. A tunable optical encoding/decoding technique based on delaying optical pulses in a vector of optical delay line (ODLs) loops is designed to allow efficient mapping of the OFDM based access and data forwarding in the optical backhaul network. In this encoding scheme, optical codewords can be easily modified by dynamically changing the number of rounds that must be performed by the optical pulse in the ODL. This feature was exploited in the backhaul architecture to enable appropriate mobility management schemes and allow seamless handover between attocells. Performance evaluation using simulation was performed to show that the proposed optical backhaul solution can achieve high transmission capacity with reduced latency.