Hybrid Medium Access Control Protocol for Radio-Over-Fiber Networks

The oncoming Internet-of-things (IoT) applications and smart machine-to-machine (M2M) communication lead to an enormous increase in network traffic. To meet the escalating demands of these time-critical applications, we need a hybrid optical-wireless network, for which the radio-over-fiber (RoF) technology is a promising candidate. These networks need to support the stringent delay requirements of the above applications for a large number of mobile users. However, the existing user registration and identification approaches for these networks are not efficient for a high user density and cannot keep the overall mean delay within the permissible limit for such applications. In this article, we present a hybrid medium access control (MAC) protocol for the RoF network, for which we propose hybrid user identification and neighbor-aware hybrid user identification algorithms for high user density. Further, the MAC protocol uses a gated polling method for data transfer. Moreover, we propose an analytical delay model for the hybrid MAC protocol, which gives overall end-to-end mean delay considering user identification and data transfer. We verify it with the results obtained from the simulations. Finally, we evaluate the mean delay and packet loss rate of the proposed algorithms by varying the network load, user density, and fiber length and benchmark the performance of the proposed algorithm with the state-of-the-art (SoA).