Contents 1. Introduction
Recently, the visible light communication (VLC) is considered to be a promising new-frequency technology combined with lighting and communication for B5G/6G applications. Ultra-high reliability and bidirectional communication is two of stringent network demands for LiFi and 6G [1]. However, the LiFi network with bidirectional VLC link suffers not only the multipath interference, multi-users access interference, inter-symbol interference, et al., but also self-interference (SI) from its own transmitter. Interference management was investigated in [2]. Authors of [3], [4] investigated the feasibly of bidirectional communication for VLC. The SI and a SI cancellation (SIC) approach were investigated in [4]. These works cannot suppress the interferences completely, which will lead to unreliable link with RF network. Hence, it is necessary to investigate the MAC layer reliable transmission for VLC link. The conventional automatic repeat request (ARQ) reliable transmission protocols such as Pipelined Reliable, Go-Back-N (GBN) and Selective Repeat (SR) have been adopt for VLC in [5], [6] to improve transmission success rate, and furthermore, the bandwidth occupation problem of conventional ARQ due to the transmission of acknowledgments (ACKs) should be considered for practical application.
