On the Reshape and Comparison of Medium Access Strategies for Infrared Indoor Uplink

In the framework of indoor optical wireless communications, a lot of attention has been paid to the downlink, usually implemented via the new paradigm of Visible Light Communication (VLC). On the other side, the uplink communication process is often dropped and the access in uplink is usually performed by other available wireless technologies, such as the Radio Frequency (RF). In this work, we analyze and compare the performance offered by different access approaches in the context of uplink infrared (IR) communication. Specifically, we consider traditional Time Division Multiple Access, ALOHA and Carrier Sensing Multiple Access with Collision Avoidance approaches, potentially reshaped for IR indoor scenario. Indeed, due to the mainly line-of-sight propagation features of the optical wireless channel, CSMA/CA is rephrased so as to work due to the impossibility of users of applying a true (RF-like) sensing mechanism. We report the performance in terms of efficiency and access probability by considering the impact of different parameters as channel capacity, number of users and burstiness of the services/applications.