Reserve before transmit (RBT): VLC MAC layer frame structure for 5G indoor internet applications

Abstract

For achieving high bandwidth, fast, and robust communication in 5G, multiple technologies are needed to work under heterogeneous networks. Visible light communication, due to its high bandwidth, low latency, and small interference area, will be a significant part of 5G along with mmwave. In this paper, a new frame structure has been proposed that implements reserve before transmit scheme. In this scheme, the active portion of the frame starts with contention access‐based reservation period (RP) followed by access point response (RES Reply) and TDMA‐based guaranteed time slots for successful nodes. In contrast to fixed slot assignment in TDMA, contention‐based reservation avoids idle slot wastage due to fixed allotment. Moreover, small reserve packets keep medium busy for a short time, the benefit of which is a lower probability of failed channel access. The proposed scheme has been compared with IEEE 802.15.7 for a sufficiently large length of RP. A Markov model of the system has been developed for analyzing the effect of RP length on the network performance. The result depicts that reserve before transmit–based frame structure provides an increase of 170% in reliability and decrease of 80% in channel access delay as compared to existing IEEE 802.15.7 CSMA/CA‐based access.