Bacteria communicate with one another by exchanging specific chemical signals called autoinducers. This process, also called quorum sensing, enables a cluster of bacteria to regulate their gene expression and behaviour collectively and synchronously, such as bioluminescence, virulence, sporulation and conjugation. Bacteria assess their population density by detecting the concentration of autoinducers. In Vibrio fischeri, which is a heterotrophic Gram-negative marine bacterium, quorum sensing relies on the synthesis, accumulation and subsequent sensing of a signalling molecule (3-oxo-C6-HSL, an N-acyl homoserine lactone or AHL). In this work, a data link layer protocol for a bacterial communication paradigm based on diffusion is introduced, considering two populations of bacteria as the transmitter node and the receiver node, instead of employing two individual bacteria. Moreover, some initial results are provided, which concern the application of the Stop-N-Wait Automatic Repeat reQuest (SW-ARQ) schemes to the proposed model. The performances of the system are later evaluated, in terms of the transmission time, frame error rate, energy consumption and transmission efficiency. 
Performance of SW-ARQ in bacterial quorum communications