20. Multiple Access in Visible Light Communication Networks

Visible light communication (VLC) is a high-speed wireless communication technology that has emerged in the recent years, as a strong alternative to existing communication technologies. The features such as high data rates, immunity to electromagnetic interference, and operation in unlicensed bands with high reuse factor make it a favorable option for broadband wireless communications. In 2011, the Institute of Electrical and Electronics Engineers (IEEE) published the 802.15.7 standard as a member of the personal communications family of standards which defines the physical and medium access control (MAC) layers of VLC. This chapter starts with an overview of multiple access techniques that can be considered for VLC networks with inherently directional light sources. The second part of the chapter focuses on the IEEE 802.15.7 VLC standard and thoroughly discusses MAC protocols therein, namely non-beacon mode without CSMA/CA; non-beacon mode with CSMA/CA; beacon-enabled mode without CSMA/CA and beacon-enabled mode with CSMA/CA. The performance of a standard-compliant VLC network is presented in terms of for throughput, drop probability, and power consumption.