###### Abstract  
Visible light communications (VLC) is an emerging and promising concept that is capable of solving the major challenges of 5G and Internet of Things (IoT) communication systems. Moreover, due to the usage of light-emitting diodes (LEDs) in almost every aspect of our daily life VLC is providing massive connectivity for various types of massive IoT communications ranging from machine-to-machine, vehicle-to-infrastructure, infrastructure-to-vehicle, chip-to-chip as well as device-to-device. In this paper, we undertake a comprehensive review of the prospects of implementing VLC for IoT. Moreover, we investigate existing and proposed approaches implemented in the application of VLC for IoT. Additionally, we look at the challenges faced in applying VLC for IoT and offer solutions where applicable. Then, we identify future research directions in the implementation of VLC for IoT. visible light communications; internet of things; 5G; massive IoT connectivity; large scale VLC-IoT communication; light-emitting diodes; LED modulation; optical wave communications +
Footnote †: journal: _technologies_  
0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-00000-0000-000  
for highly secured connections where wireless data transmission is intended to remain within the range of an access point [20; 21]. For all these reasons, VLC can be applied to most IoT-based smart systems. As a result, a new paradigm in wireless communication known as the internet of light-emitting diode (LED) which integrates IoT with VLC using LED has been introduced and is being investigated. For instance, this technology has been applied in indoor navigation and art gallery monitoring where an array of LEDs on the ceiling of departmental stores and museums which act as a source of illumination are used to transmit the position of certain products and artworks to a user mobile device [19; 22; 23; 24]. Another area of application is in the automotive industry where LED headlights and taillights of modern cars have been used in automobile collision prevention systems through vehicular VLC [11; 14; 25]. In addition, VLC-IoT can be applied to transmit medical data in biomedical sensing and data transmission [19]. These and more attributes have made VLC an attractive alternative solution to RF signals for high data rate transmission and limitless broadband solutions. As a result, there is a new upsurge in research contributions on VLC and on how to improve different aspects of VLC communications. Additionally, many scientists and engineers are now making attempts in implementing VLC for different application areas to overcome specific communications challenges. Unfortunately, there is a dearth of contributions highlighting the potentials, prospects, approaches, challenges, and solutions on the implementation of VLC for IoT communications. Therefore, we recognize the need for an effort that combines the above-mentioned in a single work. The contributions in this paper are our attempt to provide a comprehensive review of the VLC-IoT paradigm and our contributions are summarized as follows:  
1. A point-by-point discussion on whether IoT needs VLC for optimal network performance or not is presented. 2. A network architecture prototype for the deployment of prospective VLC-IoT networks is proposed. 3. The existing and proposed approaches used in the implementation of VLC for IoT are presented. 4. The benefits and challenges of implementing VLC for IoT are presented and solutions are suggested where applicable. 5. Future research directions are identified and discussed on different aspects of VLC and the application of VLC technology. To the best of our knowledge, there is yet to be a comprehensive survey that combines the prospects, existing and proposed approaches, challenges, solutions, future research directions in applying VLC for IoT in a single review paper. The rest of the work is organized as follows. Section 2 discusses related contributions. In Section 3, an overview of the VLC-IoT concept is presented.