Performance Analysis of Improved Backoff Scheme for Full Duplex CSMA/CA in VLC Networks

摘要

IEEE 802.15.7 visible light communication (VLC) networks suffer from performance degradation caused by the hidden device problems due to the directional transmission with narrow beamwidth. One of the solutions for the hidden device is to apply a full-duplex transmission technique to the VLC networks. This approach enables to mitigate collisions induced by hidden devices. As a side effect of applying the full-duplex transmission, however, the data-packet discard by reaching the retransmission limit occurs frequently in the networks. This paper proposes an improved backoff scheme to suppress the packet discard. In the proposed backoff scheme, the values of the backoff exponent (BE) and the number of backoff stage (NB) in IEEE 802.15.7 are increased only when the data packet transmission fails. To evaluate the system performance theoretically, in addition, this paper establishes the analytical models, including operations of the improved backoff scheme. The results from simulation and theoretical analysis show the effectiveness of the proposed scheme.