Hybrid Visible-Light/RF Communication System for Mission-Critical IoT Applications

The mission-critical internet of things (IoT) has recently evolved to cover many applications such as e-health, power distribution systems, industrial and smart homes and cities. Such applications are anticipated to work every time without any fail which requires a constant data transmission. Hybrid communication systems are often used to provide reliable transmission, improve the performance of communication systems and provide better mobility to the end users. Contrary to the previous works on this area which discuss the implementation of relays between different communication links, the authors of this paper study the performance of cooperative visible-light communication (VLC) and radiofrequency (RF) communication systems with the presence of AF relay. The performance of the system under consideration is analyzed in terms of ergodic capacity. A mathematical method is exploited for this hybrid system to formulate the overall capacity of the proposed system by using the characteristics of the VLC and RF channels. The analytical results of the derived expression are verified by Monte Carlo simulations throughout this letter. The authors also investigate the effect of the several system parameters on its performance. The results revealed that the length of each link has a negative impact on the system performance. It was also found that the capacity of the integrated VLC/RF system is significantly improved by increasing the AF relay gain.