Secure VLC for Wide-Area Indoor IoT Connectivity

For Internet of Things (IoT) connectivity, visible light communication (VLC) can play an important role, compared to traditional radio frequency (RF) communication. VLC does not interfere with existing RF communication, and the frequency spectrum is unregulated. Additionally, in an indoor area, VLC can provide secure communication. This study proposes an authentication-based framework that enhances security at the user end. In addition, we have modified the multiple pulse position modulation (MPPM) to map digits and send particulate matter (PM) data in broad area coverage. To reduce communication channel usage, we take the difference between two consecutive values instead of sending the whole value, which enables us to transmit the same volume of data in fewer optical signals using the proposed modulation. The comparative analysis result shows that the proposed modulation can transmit PM data more efficiently than other modulation techniques. We also provided delay analysis for proper synchronization for connectivity between nodes. The modulation was tested in the case of multihop connectivity to send data on long distance about 36 m in real time.