As the LED lamps are naturally connected to the powerline, the integration of powerline communication (PLC) and visible light communication (VLC) seems to be trivial. In fact, cascading VLC to PLC is not very simple especially because their channels are not designed for communication purposes. The PLC and VLC channels suffer from severe attenuation with increasing frequency. Thus, the cascading of these two channels will lead to a very limited bandwidth which can complicate the PLC-VLC integration. Few experimental studies are carried out to prove the feasibility of PLC-VLC integration, particularly those based on the amplify and forward (AF) relay. Therefore, PLC-VLC broadband transmission is demonstrated in this paper without making any changes to the transmitted PLC signal before traveling through the optical system. A theoretical study is also carried out to design LED luminaires capable of providing both lighting and communication. This study extrapolates the experimental results of the small-scale PLC-VLC testbed to design a PLC-VLC system for typical indoor applications.

Techniques that improve interfacing between powerline communication (PLC) systems and LED-based visible light communication (VLC) systems start to gain attention in recent years. Indeed, this hybrid system is able to provide simultaneously power, lighting, and data transmission. Contrariwise, if the integration between PLC and commercial LED bulbs is done unintentionally, the risks of PLC data leakage by commercial LED bulbs must be carefully analyzed. Thus, in this paper, the risks of eavesdropping on the PLC network via commercial LED bulbs are studied. The impact of the LED driver on PLC data leakage through LED bulbs is explained. The electrical-optical channel transfer function for different LED bulbs and the power spectral density of the signal received through the LED bulbs when two commercial powerline modems are plugged into the same power line are measured. Afterwards, pseudo random binary sequence signals are injected into the electrical-optical channel in order to assess quantitatively the possibility to extract information from the received signal. Finally, simple LED driver modifications that foster and increase the leakage are analyzed.

The integration of powerline communication (PLC) with visible light communication (VLC) has attracted the attention of many researchers. Cascading these two techniques offers the possibility of performing a wired transmission over existing powerline infrastructure and a last-mile energy-efficient wireless transmission through pre-installed LEDs for indoor illumination. Therefore, VLC should be deeply analyzed to optimize its integration with other systems. So far, most research has only modeled the channel and modulation bandwidth of the VLC system. However, the electrical and optical aspects are rarely taken into account and there is no explicit expression of the received signal as a function of that emitted. So in this paper, An explicit expression is proposed allowing a direct calculation of the photo-current as a function of the transmitted current taking into account the optical, electrical, and frequency behavior of the VLC system. This expression is validated using measurement results.Index Terms-VLC channel, LED frequency response, optical power, photo-current.